Section

[Code of Federal Regulations]
[Title 40, Volume 20]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR136.5]

[Page 37-337]

TITLE 40--PROTECTION OF ENVIRONMENT

CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

PART 136_GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS--Table of Contents

Sec. 136.5 Approval of alternate test procedures.

(a) The Regional Administrator of the region in which the discharge
will occur has final responsibility for approval of any alternate test
procedure proposed by the responsible person or firm making the
discharge.
(b) Within thirty days of receipt of an application, the Director
will forward such application proposed by the responsible person or firm
making the discharge, together with his recommendations, to the Regional
Administrator. Where the Director recommends rejection of the
application for scientific and technical reasons which he provides, the
Regional Administrator shall deny the application, and shall forward a
copy of the rejected application and his decision to the Director of the
State Permit Program and to the Director of the Analytical Methods
Staff, Washington, DC.
(c) Before approving any application for an alternate test procedure
proposed by the responsible person or firm making the discharge, the
Regional Administrator shall forward a copy of the application to the
Director of the Analytical Methods Staff, Washington, DC.
(d) Within ninety days of receipt by the Regional Administrator of
an application for an alternate test procedure, proposed by the
responsible person or firm making the discharge, the Regional
Administrator shall notify the applicant and the appropriate State
agency of approval or rejection, or shall specify the additional
information which is required to determine whether to approve the
proposed test procedure. Prior to the expiration of such ninety day
period, a recommendation providing the scientific and other technical
basis for acceptance or rejection will be forwarded to the Regional
Administrator by the Director of the Analytical Methods Staff,
Washington, DC. A copy of all approval and rejection notifications will
be forwarded to the Director, Analytical Methods Staff, Washington, DC,
for the purposes of national coordination.
(e) Approval for nationwide use. (1) Within sixty days of the
receipt by the Director of the Analytical Methods Staff, Washington, DC,
of an application for an alternate test procedure for nationwide use,
the Director of the Analytical Methods Staff shall notify the applicant
in writing whether the application is complete. If the application is
incomplete, the applicant shall be informed of the information necessary
to make the application complete.
(2) Within ninety days of the receipt of a complete package, the
Analytical Methods Staff shall perform any analysis necessary to
determine whether the alternate method satisfies the applicable
requirements of this part, and the Director of the Analytical Methods
Staff shall recommend to the Administrator that he/she approve or reject
the application and shall also notify the applicant of such
recommendation.
(3) As expeditiously as practicable, an alternate method determined
by the Administrator to satisfy the applicable requirements of this part
shall be proposed by EPA for incorporation in subsection 136.3 of 40 CFR
part 136. EPA shall make available for review all the factual bases for
its proposal, including any performance data submitted by the applicant
and any available EPA analysis of those data.
(4) Following a period of public comment, EPA shall, as
expeditiously as practicable, publish in the Federal Register a final
decision to approve or reject the alternate method.

[38 FR 28760, Oct. 16, 1973, as amended at 41 FR 52785, Dec. 1, 1976; 55
FR 33440, Aug. 15, 1990; 62 FR 30763, June 5, 1997]

Appendix A to Part 136--Methods for Organic Chemical Analysis of
Municipal and Industrial Wastewater

Method 601--Purgeable Halocarbons

1. Scope and Application

1.1 This method covers the determination of 29 purgeable
halocarbons.
The following parameters may be determined by this method:

------------------------------------------------------------------------
STORET
Parameter No. CAS No.
------------------------------------------------------------------------
Bromodichloromethane........................... 32101 75-27-4
Bromoform...................................... 32104 75-25-2
Bromomethane................................... 34413 74-83-9
Carbon tetrachloride........................... 32102 56-23-5
Chlorobenzene.................................. 34301 108-90-7
Chloroethane................................... 34311 75-00-3
2-Chloroethylvinyl ether....................... 34576 100-75-8
Chloroform..................................... 32106 67-66-3

[[Page 38]]

Chloromethane.................................. 34418 74-87-3
Dibromochloromethane........................... 32105 124-48-1
1,2-Dichlorobenzene............................ 34536 95-50-1
1,3-Dichlorobenzene............................ 34566 541-73-1
1,4-Dichlorobenzene............................ 34571 106-46-7
Dichlorodifluoromethane........................ 34668 75-71-8
1,1-Dichloroethane............................. 34496 75-34-3
1,2-Dichloroethane............................. 34531 107-06-2
1,1-Dichloroethane............................. 34501 75-35-4
trans-1,2-Dichloroethene....................... 34546 156-60-5
1,2-Dichloropropane............................ 34541 78-87-5
cis-1,3-Dichloropropene........................ 34704 10061-01-5
trans-1,3-Dichloropropene...................... 34699 10061-02-6
Methylene chloride............................. 34423 75-09-2
1,1,2,2-Tetrachloroethane...................... 34516 79-34-5
Tetrachloroethene.............................. 34475 127-18-4
1,1,1-Trichloroethane.......................... 34506 71-55-6
1,1,2-Trichloroethane.......................... 34511 79-00-5
Tetrachloroethene.............................. 39180 79-01-6
Trichlorofluoromethane......................... 34488 75-69-4
Vinyl chloride................................. 39715 75-01-4
------------------------------------------------------------------------

1.2 This is a purge and trap gas chro[chyph]ma[chyph]tographic (GC)
method applicable to the determination of the compounds listed above in
municipal and industrial discharges as provided under 40 CFR 136.1. When
this method is used to analyze unfamiliar samples for any or all of the
compounds above, compound identifications should be supported by at
least one additional qualitative technique. This method describes
analytical conditions for a second gas chromatographic column that can
be used to confirm measurements made with the primary column. Method 624
provides gas chromatograph/mass spectrometer (GC/MS) conditions
appropriate for the qualitative and quantitative confirmation of results
for most of the parameters listed above.
1.3 The method detection limit (MDL, defined in Section 12.1)
¹ for each parameter is listed in Table 1. The MDL for a
specific wastewater may differ from those listed, depending upon the
nature of interferences in the sample matrix.
1.4 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.5 This method is restricted to use by or under the supervision of
analysts experienced in the operation of a purge and trap system and a
gas chromatograph and in the interpretation of gas chromatograms. Each
analyst must demonstrate the ability to generate acceptable results with
this method using the procedure described in Section 8.2.

2. Summary of Method

2.1 An inert gas is bubbled through a 5-mL water sample contained in
a specially-designed purging chamber at ambient temperature. The
halocarbons are efficiently transferred from the aqueous phase to the
vapor phase. The vapor is swept through a sorbent trap where the
halocarbons are trapped. After purging is completed, the trap is heated
and backflushed with the inert gas to desorb the halocarbons onto a gas
chromatographic column. The gas chromatograph is temperature programmed
to separate the halocarbons which are then detected with a halide-
specific detector.^2,3
2.2 The method provides an optional gas chromatographic column that
may be helpful in resolving the compounds of interest from interferences
that may occur.

3. Interferences

3.1 Impurities in the purge gas and organic compounds outgassing
from the plumbing ahead of the trap account for the majority of
contamination problems. The analytical system must be demonstrated to be
free from contamination under the conditions of the analysis by running
laboratory reagent blanks as described in Section 8.1.3. The use of non-
Teflon plastic tubing, non-Teflon thread sealants, or flow controllers
with rubber components in the purge and trap system should be avoided.
3.2 Samples can be contaminated by diffusion of volatile organics
(particularly fluorocarbons and methylene chloride) through the septum
seal ilto the sample during shipment and storage. A field reagent blank
prepared from reagent water and carried through the sampling and
handling protocol can serve as a check on such contamination.
3.3 Contamination by carry-over can occur whenever high level and
low level samples are sequentially analyzed. To reduce carry-over, the
purging device and sample syringe must be rinsed with reagent water
between sample analyses. Whenever an unusually concentrated sample is
encountered, it should be followed by an analysis of reagent water to
check for cross contamination. For samples containing large amounts of
water-soluble materials, suspended solids, high boiling compounds or
high organohalide levels, it may be necessary to wash out the purging
device with a detergent solution, rinse it with distilled water, and
then dry it in a 105[deg]C oven between analyses. The trap and other
parts of the system are also subject to contamination; therefore,
frequent bakeout and purging of the entire system may be required.

4. Safety

4.1 The toxicity or carcinogenicity of each [chyph]reagent used in
this method has not been precisely defined; however, each chemical
compound should be treated as a potential health hazard. From this
viewpoint, exposure to these chemicals must be reduced to the lowest
possible level by whatever means available. The laboratory is
responsible for maintaining a current awareness file of

[[Page 39]]

OSHA regulations regarding the safe handling of the chemicals specified
in this method. A reference file of material data handling sheets should
also be made available to all personnel involved in the chemical
analysis. Additional references to laboratory safety are available and
have been identified ^4-6 for the information of the analyst.
4.2 The following parameters covered by this method have been
tentatively classified as known or suspected, human or mammalian
carcinogens: carbon tetrachloride, chloroform, 1,4-dichlorobenzene, and
vinyl chloride. Primary standards of these toxic compounds should be
prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be
worn when the analyst handles high concentrations of these toxic
compounds.

5. Apparatus and Materials

5.1 Sampling equipment, for discrete sampling.
5.1.1 Vial--25-mL capacity or larger, equipped with a screw cap with
a hole in the center (Pierce 13075 or equivalent). Detergent
wash, rinse with tap and distilled water, and dry at 105 [deg]C before
use.
5.1.2 Septum--Teflon-faced silicone (Pierce 12722 or
equivalent). Detergent wash, rinse with tap and distilled water, and dry
at 105 [deg]C for 1 h before use.
5.2 Purge and trap system--The purge and trap system consists of
three separate pieces of equipment: a purging device, trap, and
desorber. Several complete systems are now commercially available.
5.2.1 The purging device must be designed to accept 5-mL samples
with a water column at least 3 cm deep. The gaseous head space between
the water column and the trap must have a total volume of less than 15
mL. The purge gas must pass through the water column as finely divided
bubbles with a diameter of less than 3 mm at the origin. The purge gas
must be introduced no more than 5 mm from the base of the water column.
The purging device illustrated in Figure 1 meets these design criteria.
5.2.2 The trap must be at least 25 cm long and have an inside
diameter of at least 0.105 in. The trap must be packed to contain the
following minimum lengths of adsorbents: 1.0 cm of methyl silicone
coated packing (Section 6.3.3), 7.7 cm of 2,6-diphenylene oxide polymer
(Section 6.3.2), 7.7 cm of silica gel (Section 6.3.4), 7.7 cm of coconut
charcoal (Section 6.3.1). If it is not necessary to analyze for
dichlorodifluoromethane, the charcoal can be eliminated, and the polymer
section lengthened to 15 cm. The minimum specifications for the trap are
illustrated in Figure 2.
5.2.3 The desorber must be capable of rapidly heating the trap to
180 [deg]C. The polymer section of the trap should not be heated higher
than 180 [deg]C and the remaining sections should not exceed 200 [deg]C.
The desorber illustrated in Figure 2 meets these design criteria.
5.2.4 The purge and trap system may be assembled as a separate unit
or be coupled to a gas chromatograph as illustrated in Figures 3 and 4.
5.3 Gas chromatograph--An analytical system complete with a
temperature programmable gas chromatograph suitable for on-column
injection and all required accessories including syringes, analytical
columns, gases, detector, and strip-chart recorder. A data system is
recommended for measuring peak areas.
5.3.1 Column 1--8 ft long x 0.1 in. ID stainless steel or glass,
packed with 1% SP-1000 on Carbopack B (60/80 mesh) or equivalent. This
column was used to develop the method performance statements in Section
12. Guidelines for the use of alternate column packings are provided in
Section 10.1.
5.3.2 Column 2--6 ft long x 0.1 in. ID stainless steel or glass,
packed with chemically bonded n-octane on Porasil-C (100/120 mesh) or
equivalent.
5.3.3 Detector--Electrolytic conductivity or microcoulometric
detector. These types of detectors have proven effective in the analysis
of wastewaters for the parameters listed in the scope (Section 1.1). The
electrolytic conductivity detector was used to develop the method
performance statements in Section 12. Guidelines for the use of
alternate detectors are provided in Section 10.1.
5.4 Syringes--5-mL glass hypodermic with Luerlok tip (two each), if
applicable to the purging device.
5.5 Micro syringes--25-[mu]L, 0.006 in. ID needle.
5.6 Syringe valve--2-way, with Luer ends (three each).
5.7 Syringe--5-mL, gas-tight with shut-off valve.
5.8 Bottle--15-mL, screw-cap, with Teflon cap liner.
5.9 Balance--Analytical, capable of accurately weighing 0.0001 g.

6. Reagents

[[Page 40]]

the water to a narrow mouth screw-cap bottle and seal with a Teflon-
lined septum and cap.
6.2 Sodium thiosulfate--(ACS) Granular.
6.3 Trap Materials:
6.3.1 Coconut charcoal--6/10 mesh sieved to 26 mesh, Barnabey
Cheney, CA-580-26 lot M-2649 or equivalent.
6.3.2 2,6-Diphenylene oxide polymer--Tenax, (60/80 mesh),
chromatographic grade or equivalent.
6.3.3 Methyl silicone packing--3% OV-1 on Chromosorb-W (60/80 mesh)
or equivalent.
6.3.4 Silica gel--35/60 mesh, Davison, grade-15 or equivalent.
6.4 Methanol--Pesticide quality or equivalent.
6.5 Stock standard solutions--Stock standard solutions may be
prepared from pure standard materials or purchased as certified
solutions. Prepare stock standard solutions in methanol using assayed
liquids or gases as appropriate. Because of the toxicity of some of the
organohalides, primary dilutions of these materials should be prepared
in a hood. A NIOSH/MESA approved toxic gas respirator should be used
when the analyst handles high concentrations of such materials.
6.5.1 Place about 9.8 mL of methanol into a 10-mL ground glass
stoppered volumetric flask. Allow the flask to stand, unstoppered, for
about 10 min or until all alcohol wetted surfaces have dried. Weigh the
flask to the learest 0.1 mg.
6.5.2 Add the assayed reference material:
6.5.2.1 Liquid--Using a 100 [mu]L syringe, immediately add two or
more drops of assayed reference material to the flask, then reweigh. Be
sure that the drops fall directly into the alcohol without contacting
the neck of the flask.
6.5.2.2 Gases--To prepare standards for any of the six halocarbons
that boil below 30 [deg] C (bromomethane, chloroethane,
chloro[chyph]methane, dichlorodifluoromethane,
[chyph]trichlorofluoromethane, vinyl chloride), [chyph]fill a 5-mL
valved gas-tight syringe with the reference standard to the 5.0-mL mark.
Lower the needle to 5 mm above the methanol meniscus. Slowly introduce
the reference standard above the surface of the liquid (the heavy gas
will rapidly dissolve into the methanol).
6.5.3 Reweigh, dilute to volume, stopper, then mix by inverting the
flask several times. Calculate the concentration in [mu]g/[mu]L from the
net gain in weight. When compound purity is assayed to be 96% or
greater, the weight can be used without correction to calculate the
concentration of the stock standard. Commercially prepared stock
standards can be used at any concentration if they are certified by the
malufacturer or by an independent source.
6.5.4 Transfer the stock standard solution into a Teflon-sealed
screw-cap bottle. Store, with minimal headspace, at -10 to -20 [deg]C
and protect from light.
6.5.5 Prepare fresh standards weekly for the six gases and 2-
chloroethylvinyl ether. All other standards must be replaced after one
month, or sooner if comparison with check standards indicates a problem.
6.6 Secondary dilution standards--Using stock standard solutions,
prepare secondary dilution standards in methanol that contain the
compounds of interest, either singly or mixed together. The secondary
dilution standards should be prepared at concentrations such that the
aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will
bracket the working range of the analytical system. Secondary dilution
standards should be stored with minimal headspace and should be checked
frequently for signs of degradation or evaporation, especially just
prior to preparing calibration standards from them.
6.7 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

[[Page 41]]

response to concentration (calibration factor) is a constant over the
working range (<10% relative standard deviation, RSD), linearity through
the origin can be assumed and the average ratio or calibration factor
can be used in place of a calibration curve.
7.4 Internal standard calibration procedure--To use this approach,
the analyst must select one or more internal standards that are similar
in analytical behavior to the compounds of interest. The analyst must
further demonstrate that the measurement of the internal standard is not
affected by method or matrix interferences. Because of these
limitations, no internal standard can be suggested that is applicable to
all samples. The compounds recommended for use as surrogate spikes in
Section 8.7 have been used successfully as internal standards, because
of their generally unique retention times.
7.4.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest as described in
Section 7.3.1.
7.4.2 Prepare a spiking solution containing each of the internal
standards using the procedures described in Sections 6.5 and 6.6. It is
recommended that the secondary dilution standard be prepared at a
concentration of 15 [mu]g/mL of each internal standard compound. The
addition of 10 [mu]L of this standard to 5.0 mL of sample or calibration
standard would be equivalent to 30 [mu]g/L.
7.4.3 Analyze each calibration standard according to Section 10,
adding 10 [mu]L of internal standard spiking solution directly to the
syringe (Section 10.4). Tabulate peak height or area responses against
concentration for each compound and internal standard, and calculate
response factors (RF) for each compound using Equation 1.
[GRAPHIC] [TIFF OMITTED] TC15NO91.094

Equation 1
where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Cis=Concentration of the internal standard.
Cs=Concentration of the parameter to be measured.

If the RF value over the working range is a constant (<10% RSD), the RF
can be assumed to be invariant and the average RF can be used for
calculations. Alternatively, the results can be used to plot a
calibration curve of response ratios, As/Ais, vs.
RF.
7.5 The working calibration curve, calibration factor, or RF must be
verified on each working day by the measurement of a QC check sample.
7.5.1 Prepare the QC check sample as described in Section 8.2.2.
7.5.2 Analyze the QC check sample according to Section 10.
7.5.3 For each parameter, compare the response (Q) with the
corresponding calibration acceptance criteria found in Table 2. If the
responses for all parameters of interest fall within the designated
ranges, analysis of actual samples can begin. If any individual Q falls
outside the range, proceed according to Section 7.5.4.
Note: The large number of parameters in Table 2 present a
substantial probability that one or more will not meet the calibration
acceptance criteria when all parameters are analyzed.
7.5.4 Repeat the test only for those parameters that failed to meet
the calibration acceptance criteria. If the response for a parameter
does not fall within the range in this second test, a new calibration
curve, calibration factor, or RF must be prepared for that parameter
according to Section 7.3 or 7.4.

8. Quality Control

[[Page 42]]

8.1.5 The laboratory must, on an ongoing basis, demonstrate through
the analyses of quality control check standards that the operation of
the measurement system is in control. This procedure is described in
Section 8.4. The frequency of the check standard analyses is equivalent
to 10% of all samples analyzed but may be reduced if spike recoveries
from samples (Section 8.3) meet all specified quality control criteria.
8.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is described in
Section 8.5.
8.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
8.2.1 A quality control (QC) check sample concentrate is required
containing each parameter of interest at a concentration of 10 [mu]g/mL
in methanol. The QC check sample concentrate must be obtained from the
U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory in Cincinnati, Ohio, if available. If not available
from that source, the QC check sample concentrate must be obtained from
another external source. If not available from either source above, the
QC check sample concentrate must be prepared by the laboratory using
stock standards prepared independently from those used for calibration.
8.2.2 Prepare a QC check sample to contain 20 [mu]g/L of each
parameter by adding 200 [mu]L of QC check sample concentrate to 100 mL
of reagent water.
8.2.3 Analyze four 5-mL aliquots of the well-mixed QC check sample
according to Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter of
interest using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively, found in
Table 2. If s and X for all parameters of interest meet the acceptance
criteria, the system performance is acceptable and analysis of actual
samples can begin. If any individual s exceeds the precision limit or
any individual X falls outside the range for accuracy, then the system
performance is unacceptable for that parameter.
Note: The large number of parameters in Table 2 present a
substantial probability that one or more will fail at least one of the
acceptance criteria when all parameters are analyzed.
8.2.6 When one or more of the parameters tested fail at least one of
the acceptance criteria, the analyst must proceed according to Section
8.2.6.1 or 8.2.6.2.
8.2.6.1 Locate and correct the source of the problem and repeat the
test for all parameters of interest beginning with Section 8.2.3.
8.2.6.2 Beginning with Section 8.2.3, repeat the test only for those
parameters that failed to meet criteria. Repeated failure, however, will
confirm a general problem with the measurement system. If this occurs,
locate and correct the source of the problem and repeat the test for all
compounds of interest beginning with Section 8.2.3.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at 20 [mu]g/L or 1 to 5 times higher than the background
concentration determined in Section 8.3.2, whichever concentration would
be larger.
8.3.2 Analyze one 5-mL sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second 5-mL sample aliquot with 10
[mu]L of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100(A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 2. These acceptance
criteria were calculated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.⁷ If spiking was performed at a concentration lower than
20 [mu]g/L, the analyst must use either the QC acceptance criteria in
Table 2, or optional QC acceptance criteria calculated for the specific
spike concentration. To calculate optional acceptance criteria for the
recovery of a parameter: (1) Calculate accuracy (X') using the equation
in Table 3, substituting the spike concentration (T) for C; (2)
calculate overall precision (S') using the equation in Table 3,
substituting X' for X; (3) calculate the range for recovery at the spike
concentration as (100 X'/T)+-2.44(100 S'/T)%.⁷

[[Page 43]]

8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory. If the entire list of parameters in Table 2 must be measured
in the sample in Section 8.3, the probability that the analysis of a QC
check standard will be required is high. In this case the QC check
standard should be routinely analyzed with the spiked sample.
8.4.1 Prepare the QC check standard by adding 10 [mu]L of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent water.
The QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
2. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2sp to P+2sp.
If p=90% and sp=10%, for example, the accuracy interval is
expressed as 70-110%. Update the accuracy assessment for each parameter
on a regular basis (e.g. after each five to ten new accuracy
measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates may be analyzed to assess the
precision of the environmental measurements. When doubt exists over the
identification of a peak on the chromatogram, confirmatory techniques
such as gas chromatography with a dissimilar column, specific element
detector, or mass spectrometer must be used. Whenever possible, the
laboratory should analyze standard reference materials and participate
in relevant performance evaluation studies.
8.7 The analyst should monitor both the performance of the
analytical system and the effectiveness of the method in deal[chyph]ing
with each sample matrix by spiking [chyph]each sample, standard, and
reagent [chyph]water blank with surrogate halocarbons. [chyph]A
combination of bromochloromethane, [chyph]2-bromo-1-chloropropane, and
1,4-dichlorobu[chyph]tane is recommended to encompass the range of the
temperature program used in this method. From stock standard solutions
prepared as in Section 6.5, add a volume to give 750 [mu]g of each
surrogate to 45 mL of reagent water contained in a 50-mL volumetric
flask, mix and dilute to volume for a concentration of 15 ng/[mu]L. Add
10 [mu]L of this surrogate spiking solution directly into the 5-mL
syringe with every sample and reference standard analyzed. Prepare a
fresh surrogate spiking solution on a weekly basis. If the internal
standard calibration procedure is being used, the surrogate compounds
may be added directly to the internal standard spiking solution (Section
7.4.2).

9. Sample Collection, Preservation, and Handling

9.1 All samples must be iced or refrigerated from the time of
collection until analysis. If the sample contains free or combined
chlorine, add sodium thiosulfate preservative (10 mg/40 mL is sufficient
for up to 5 ppm Cl2) to the empty sample bottle just prior to
shipping to the sampling site. EPA Methods 330.4 and 330.5 may be used
for measurement of residual chlorine.⁸ Field test kits are
available for this purpose.
9.2 Grab samples must be collected in glass containers having a
total volume of at least 25 mL. Fill the sample bottle just to
overflowing in such a manner that no air bubbles pass through the sample
as the bottle is being filled. Seal the bottle so that no air bubbles
are entrapped in it. If preservative has been added, shake vigorously
for 1 min. Maintain the hermetic seal on the sample bottle until time of
analysis.
9.3 All samples must be analyzed within 14 days of
collection.³

10. Procedure

[[Page 44]]

chromatographic conditions, or detectors may be used if the requirements
of Section 8.2 are met.
10.2 Calibrate the system daily as described in Section 7.
10.3 Adjust the purge gas (nitrogen or helium) flow rate to 40 mL/
min. Attach the trap inlet to the purging device, and set the purge and
trap system to purge (Figure 3). Open the syringe valve located on the
purging device sample introduction needle.
10.4 Allow the sample to come to ambient temperature prior to
introducing it to the syringe. Remove the plunger from a 5-mL syringe
and attach a closed syringe valve. Open the sample bottle (or standard)
and carefully pour the sample into the syringe barrel to just short of
overflowing. Replace the syringe plunger and compress the sample. Open
the syringe valve and vent any residual air while adjusting the sample
volume to 5.0 mL. Since this process of taking an aliquot destroys the
validity of the sample for future analysis, the analyst should fill a
second syringe at this time to protect against possible loss of data.
Add 10.0 [mu]L of the surrogate spiking solution (Section 8.7) and 10.0
[mu]L of the internal standard spiking solution (Section 7.4.2), if
applicable, through the valve bore, then close the valve.
10.5 Attach the syringe-syringe valve assembly to the syringe valve
on the purging device. Open the syringe valves and inject the sample
into the purging chamber.
10.6 Close both valves and purge the sample for 11.0+-0.1 min at
ambient temperature.
10.7 After the 11-min purge time, attach the trap to the
chromatograph, adjust the purge and trap system to the desorb mode
(Figure 4), and begin to temperature program the gas chromatograph.
Introduce the trapped materials to the GC column by rapidly heating the
trap to 180 [deg]C while backflushing the trap with an inert gas between
20 and 60 mL/min for 4 min. If rapid heating of the trap cannot be
achieved, the GC column must be used as a secondary trap by cooling it
to [chyph]30 [deg]C (subambient temperature, if poor peak geometry or
random retention time problems persist) instead of the initial program
temperature of 45 [deg]C
10.8 While the trap is being desorbed into the gas chromatograph,
empty the purging chamber using the sample introduction syringe. Wash
the chamber with two 5-mL flushes of reagent water.
10.9 After desorbing the sample for 4 min, recondition the trap by
returning the purge and trap system to the purge mode. Wait 15 s then
close the syringe valve on the purging device to begin gas flow through
the trap. The trap temperature should be maintained at [chyph]180 [deg]C
After approximately 7 min, turn off the trap heater and open the syringe
valve to stop the gas flow through the trap. When the trap is cool, the
next sample can be analyzed.
10.10 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
can be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.
10.11 If the response for a peak exceeds the working range of the
system, prepare a dilution of the sample with reagent water from the
aliquot in the second syringe and reanalyze.

11. Calculations

11.1 Determine the concentration of individual compounds in the
sample.
11.1.1 If the external standard calibration procedure is used,
calculate the concentration of the parameter being measured from the
peak response using the calibration curve or calibration factor
determined in Section 7.3.2.
11.1.2 If the internal standard calibration procedure is used,
calculate the concentration in the sample using the response factor (RF)
determined in Section 7.4.3 and Equation 2.
Equation 2
[GRAPHIC] [TIFF OMITTED] TC15NO91.095

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Cis=Concentration of the internal standard.

11.2 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

12. Method Performance

12.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and re[chyph]ported
with 99% confidence that the value is [chyph]above zero. \1\ The MDL
concentration listed [chyph]in Table 1 were obtained using reagent
[chyph]water.¹¹. Similar results were achieved using
[chyph]representative wastewaters. The MDL actu[chyph]ally achieved in a
given analysis will [chyph]vary depending on instrument sensitivity and
matrix effects.

12.2 This method is recommended for use in the concentration range
from the MDL to

[[Page 45]]

1000xMDL. Direct aqueous injection techniques should be used to measure
concentration levels above 1000xMDL.
12.3 This method was tested by 20 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
at six concentrations over the range 8.0 to 500 [mu]g/L.⁹
Single operator precision, overall precision, and method accuracy were
found to be directly related to the concentration of the parameter and
essentially independent of the sample matrix. Linear equations to
describe these relationships are presented in Table 3.

References

1. 40 CFR part 136, appendix B.
2. Bellar, T.A., and Lichtenberg, J.J. ``Determining Volatile
Organics at Microgram-per-Litre-Levels by Gas Chromatography,'' Journal
of the American Water Works Association, 66, 739 (1974).
3. Bellar, T.A., and Lichtenberg, J.J. ``Semi-Automated Headspace
Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile
Organic Compounds,'' Proceedings from Symposium on Measurement of
Organic Pollutants in Water and Wastewater, American Society for Testing
and Materials, STP 686, C.E. Van Hall, editor, 1978.
4. ``Carcinogens--Working With Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
5. ``OSHA Safety and Health Standards, General Industry'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
6. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3 is two times the value 1.22
derived in this report.)
8. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for
Chemical Analysis of Water and Wastes, EPA 600/4-79-020, U.S.
Environmental Protection Agency, Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio 45268, March 1979.
9. ``EPA Method Study 24, Method 601--Purgeable Halocarbons by the
Purge and Trap Method,'' EPA 600/4-84-064, National Technical
Information Service, PB84-212448, Springfield, Virginia 22161, July
1984.
10. ``Method Validation Data for EPA Method 601,'' Memorandum from
B. Potter, U.S. Environmental Protection Agency, Environmental
Monitoring and Support Laboratory, Cincinnati, Ohio 45268, November 10,
1983.
11. Bellar, T. A., Unpublished data, U.S. Environmental Protection
Agency, Environmental Monitoring and Support Laboratory, Cincinnati,
Ohio 45268, 1981.

Table 1--Chromatographic Conditions and Method Detection Limits
----------------------------------------------------------------------------------------------------------------
Retention time (min)
Parameter ------------------------------------ Method detection
Column 1 Column 2 limit ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
Chloromethane............................................. 1.50 5.28 0.08
Bromomethane.............................................. 2.17 7.05 1.18
Dichlorodifluoromethane................................... 2.62 nd 1.81
Vinyl chloride............................................ 2.67 5.28 0.18
Chloroethane.............................................. 3.33 8.68 0.52
Methylene chloride........................................ 5.25 10.1 0.25
Trichlorofluoromethane.................................... 7.18 nd nd
1,1-Dichloroethene........................................ 7.93 7.72 0.13
1,1-Dichloroethane........................................ 9.30 12.6 0.07
trans-1,2-Dichloroethene.................................. 10.1 9.38 0.10
Chloroform................................................ 10.7 12.1 0.05
1,2-Dichloroethane........................................ 11.4 15.4 0.03
1,1,1-Trichloroethane..................................... 12.6 13.1 0.03
Carbon tetrachloride...................................... 13.0 14.4 0.12
Bromodichloromethane...................................... 13.7 14.6 0.10
1,2-Dichloropropane....................................... 14.9 16.6 0.04
cis-1,3-Dichloropropene................................... 15.2 16.6 0.34
Trichloroethene........................................... 15.8 13.1 0.12
Dibromochloromethane...................................... 16.5 16.6 0.09
1,1,2-Trichloroethane..................................... 16.5 18.1 0.02
trans-1,3-Dichloropropene................................. 16.5 18.0 0.20
2-Chloroethylvinyl ether.................................. 18.0 nd 0.13
Bromoform................................................. 19.2 19.2 0.20
1,1,2,2-Tetrachloroethane................................. 21.6 nd 0.03
Tetrachloroethene......................................... 21.7 15.0 0.03
Chlorobenzene............................................. 24.2 18.8 0.25
1,3-Dichlorobenzene....................................... 34.0 22.4 0.32
1,2-Dichlorobenzene....................................... 34.9 23.5 0.15

[[Page 46]]

1,4-Dichlorobenzene....................................... 35.4 22.3 0.24
----------------------------------------------------------------------------------------------------------------
Column 1 conditions: Carbopack B (60/80 mesh) coated with 1% SP-1000 packed in an 8 ft x 0.1 in. ID stainless
steel or glass column with helium carrier gas at 40 mL/min flow rate. Column temperature held at 45 [deg]C for
3 min then programmed at 8 [deg]C/min to 220 [deg]C and held for 15 min.
Column 2 conditions: Porisil-C (100/120 mesh) coated with n-octane packed in a 6 ft x 0.1 in. ID stainless steel
or glass column with helium carrier gas at 40 mL/min flow rate. Column temperature held at 50 [deg]C for 3 min
then programmed at 6 [deg]C/min to 170 [deg]C and held for 4 min.
nd=not determined.

Table 2--Calibration and QC Acceptance Criteria--Method 601 a
----------------------------------------------------------------------------------------------------------------
Limit for
Parameter Range for Q s ([mu]g/ Range for X Range P,
([mu]g/L) L) ([mu]g/L) Ps (%)
----------------------------------------------------------------------------------------------------------------
Bromodichloromethane.................................... 15.2-24.8 4.3 10.7-32.0 42-172
Bromoform............................................... 14.7-25.3 4.7 5.0-29.3 13-159
Bromomethane............................................ 11.7-28.3 7.6 3.4-24.5 D-144
Carbon tetrachloride.................................... 13.7-26.3 5.6 11.8-25.3 43-143
Chlorobenzene........................................... 14.4-25.6 5.0 10.2-27.4 38-150
Chloroethane............................................ 15.4-24.6 4.4 11.3-25.2 46-137
2-Chloroethylvinyl ether................................ 12.0-28.0 8.3 4.5-35.5 14-186
Chloroform.............................................. 15.0-25.0 4.5 12.4-24.0 49-133
Chloromethane........................................... 11.9-28.1 7.4 D-34.9 D-193
Dibromochloromethane.................................... 13.1-26.9 6.3 7.9-35.1 24-191
1,2-Dichlorobenzene..................................... 14.0-26.0 5.5 1.7-38.9 D-208
1,3-Dichlorobenzene..................................... 9.9-30.1 9.1 6.2-32.6 7-187
1,4-Dichlorobenzene..................................... 13.9-26.1 5.5 11.5-25.5 42-143
1,1-Dichloroethane...................................... 16.8-23.2 3.2 11.2-24.6 47-132
1,2-Dichloroethane...................................... 14.3-25.7 5.2 13.0-26.5 51-147
1,1-Dichloroethene...................................... 12.6-27.4 6.6 10.2-27.3 28-167
trans-1,2-Dichloroethene................................ 12.8-27.2 6.4 11.4-27.1 38-155
1,2-Dichloropropane..................................... 14.8-25.2 5.2 10.1-29.9 44-156
cis-1,3-Dichloropropene................................. 12.8-27.2 7.3 6.2-33.8 22-178
trans-1,3-Dichloropropene............................... 12.8-27.2 7.3 6.2-33.8 22-178
Methylene chloride...................................... 15.5-24.5 4.0 7.0-27.6 25-162
1,1,2,2-Tetrachloroethane............................... 9.8-30.2 9.2 6.6-31.8 8-184
Tetrachloroethene....................................... 14.0-26.0 5.4 8.1-29.6 26-162
1,1,1-Trichloroethane................................... 14.2-25.8 4.9 10.8-24.8 41-138
1,1,2-Trichloroethane................................... 15.7-24.3 3.9 9.6-25.4 39-136
Trichloroethene......................................... 15.4-24.6 4.2 9.2-26.6 35-146
Trichlorofluoromethane.................................. 13.3-26.7 6.0 7.4-28.1 21-156
Vinyl chloride.......................................... 13.7-26.3 5.7 8.2-29.9 28-163
----------------------------------------------------------------------------------------------------------------
a Criteria were calculated assuming a QC check sample concentration of 20 [mu]g/L.
Q=Concentration measured in QC check sample, in [mu]g/L (Section 7.5.3).
s=Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).
D=Detected; result must be greater than zero.

Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits
for recovery have been broadened to assure applicability of the limits to concentrations below those used to
develop Table 3.

Table 3--Method Accuracy and Precision as Functions of Concentration--Method 601
----------------------------------------------------------------------------------------------------------------
Single analyst
Parameter Accuracy, as recovery, precision, sr' ([mu]g/ Overall precision, S'
X' ([mu]g/L) L) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
Bromodichloromethane................ 1.12C-1.02 0.11X+0.04 0.20X+1.00
Bromoform........................... 0.96C-2.05 0.12X+0.58 0.21X+2.41
Bromomethane........................ 0.76C-1.27 0.28X+0.27 0.36X+0.94
Carbon tetrachloride................ 0.98C-1.04 0.15X+0.38 0.20X+0.39
Chlorobenzene....................... 1.00C-1.23 0.15X-0.02 0.18X+1.21
Choroethane......................... 0.99C-1.53 0.14X-0.13 0.17X+0.63
2-Chloroethylvinyl ether a.......... 1.00C 0.20X 0.35X
Chloroform.......................... 0.93C-0.39 0.13X+0.15 0.19X-0.02
Chloromethane....................... 0.77C+0.18 0.28X-0.31 0.52X+1.31
Dibromochloromethane................ 0.94C+2.72 0.11X+1.10 0.24X+1.68
1,2-Dichlorobenzene................. 0.93C+1.70 0.20X+0.97 0.13X+6.13
1,3-Dichlorobenzene................. 0.95C+0.43 0.14X+2.33 0.26X+2.34
1,4-Dichlorobenzene................. 0.93C-0.09 0.15X+0.29 0.20X+0.41
1,1-Dichloroethane.................. 0.95C-1.08 0.09X+0.17 0.14X+0.94
1,2-Dichloroethane.................. 1.04C-1.06 0.11X+0.70 0.15X+0.94

[[Page 47]]

1,1-Dichloroethene.................. 0.98C-0.87 0.21X-0.23 0.29X-0.40
trans-1,2-Dichloroethene............ 0.97C-0.16 0.11X+1.46 0.17X+1.46
1,2-Dichloropropane a............... 1.00C 0.13X 0.23X
cis-1,3-Dichloropropene a........... 1.00C 0.18X 0.32X
trans-1,3-Dichloropropene a......... 1.00C 0.18X 0.32X
Methylene chloride.................. 0.91C-0.93 0.11X+0.33 0.21X+1.43
1,1,2,2-Tetrachloroethene........... 0.95C+0.19 0.14X+2.41 0.23X+2.79
Tetrachloroethene................... 0.94C+0.06 0.14X+0.38 0.18X+2.21
1,1,1-Trichloroethane............... 0.90C-0.16 0.15X+0.04 0.20X+0.37
1,1,2-Trichloroethane............... 0.86C+0.30 0.13X-0.14 0.19X+0.67
Trichloroethene..................... 0.87C+0.48 0.13X-0.03 0.23X+0.30
Trichlorofluoromethane.............. 0.89C-0.07 0.15X+0.67 0.26X+0.91
Vinyl chloride...................... 0.97C-0.36 0.13X+0.65 0.27X+0.40
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
sn'=Expected single analyst standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
S\1\=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in
[mu]g/L.
C=True value for the concentration, in [mu]g/L.
X=Average recovery found for measurements of samples containing a concentration of C, in [mu]g/L.
a Estimates based upon the performance in a single laboratory.\10\

[[Page 48]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.000

[[Page 49]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.001

[[Page 50]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.002

[[Page 51]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.003

[[Page 52]]

Method 602--Purgeable Aromatics

1. Scope and Application

1.1 This method covers the determination of various purgeable
aromatics. The following parameters may be determined by this method:

------------------------------------------------------------------------
STORET
Parameter No. CAS No.
------------------------------------------------------------------------
Benzene.......................................... 34030 71-43-2
Chlorobenzene.................................... 34301 108-90-7
1,2-Dichlorobenzene.............................. 34536 95-50-1
1,3-Dichlorobenzene.............................. 34566 541-73-1
1,4-Dichlorobenzene.............................. 34571 106-46-7
Ethylbenzene..................................... 34371 100-41-4
Toluene.......................................... 34010 108-88-3
------------------------------------------------------------------------

1.2 This is a purge and trap gas chromatographic (GC) method
applicable to the determination of the compounds listed above in
municipal and industrial discharges as provided under 40 CFR 136.1. When
this method is used to analyze unfamiliar samples for any or all of the
compounds above, compound identifications should be supported by at
least one additional qualitative technique. This method describes
analytical conditions for a second gas chromatographic column that can
be used to confirm measurements made with the primary column. Method 624
provides gas chromatograph/mass spectrometer (GC/MS) conditions
appropriate for the qualitative and quantitative confirmation of results
for all of the parameters listed above.
1.3 The method detection limit (MDL, defined in Section 12.1)
¹ for each parameter is listed in Table 1. The MDL for a
specific wastewater may differ from those listed, depending upon the
nature of interferences in the sample matrix.
1.4 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.5 This method is restricted to use by or under the supervision of
analysts experienced in the operation of a purge and trap system and a
gas chromatograph and in the interpretation of gas chromatograms. Each
analyst must demonstrate the ability to generate acceptable results with
this method using the procedure described in Section 8.2.

2. Summary of Method

2.1 An inert gas is bubbled through a 5-mL water sample contained in
a specially-designed purging chamber at ambient temperature. The
aromatics are efficiently transferred from the aqueous phase to the
vapor phase. The vapor is swept through a sorbent trap where the
aromatics are trapped. After purging is completed, the trap is heated
and backflushed with the inert gas to desorb the aromatics onto a gas
chromatographic column. The gas chromatograph is temperature programmed
to separate the aromatics which are then detected with a photoionization
detector.^{2, 3}
2.2 The method provides an optional gas chromatographic column that
may be helpful in resolving the compounds of interest from interferences
that may occur.

3. Interferences

3.1 Impurities in the purge gas and organic compounds outgassing
from the plumbing ahead of the trap account for the majority of
contamination problems. The analytical system must be demonstrated to be
free from contamination under the conditions of the analysis by running
laboratory reagent blanks as described in Section 8.1.3. The use of non-
Teflon plastic tubing, non-Teflon thread sealants, or flow controllers
with rubber components in the purge and trap system should be avoided.
3.2 Samples can be contaminated by diffusion of volatile organics
through the septum seal into the sample during shipment and storage. A
field reagent blank prepared from reagent water and carried through the
sampling and handling protocol can serve as a check on such
contamination.
3.3 Contamination by carry-over can occur whenever high level and
low level samples are sequentially analyzed. To reduce carry-over, the
purging device and sample syringe must be rinsed with reagent water
between sample analyses. Whenever an unusually concentrated sample is
encountered, it should be followed by an analysis of reagent water to
check for cross contamination. For samples containing large amounts of
water-soluble materials, suspended solids, high boiling compounds or
high aromatic levels, it may be necessary to wash the purging device
with a detergent solution, rinse it with distilled water, and then dry
it in an oven at 105 [deg]C between analyses. The trap and other parts
of the system are also subject to contamination; therefore, frequent
bakeout and purging of the entire system may be required.

4. Safety

[[Page 53]]

are available and have been identified ^4-6 for the
information of the analyst.
4.2 The following parameters covered by this method have been
tentatively classified as known or suspected, human or mam[chyph]malian
carcinogens: benzene and 1,4-[chyph]dichlorobenzene. Primary standards
of [chyph]these toxic compounds should be prepared [chyph]in a hood. A
NIOSH/MESA approved [chyph]toxic gas respirator should be worn
[chyph]when the analyst handles high con[chyph]centrations of these
toxic compounds.

5. Apparatus and Materials

5.1 Sampling equipment, for discrete sampling.
5.1.1 Vial]25-mL capacity or larger, equipped with a screw cap with
a hole in the center (Pierce 13075 or equivalent). Detergent
wash, rinse with tap and distilled water, and dry at 105 [deg]C before
use.
5.1.2 Septum--Teflon-faced silicone (Pierce [chyph]12722 or
equivalent). Deter[chyph]gent wash, rinse with tap and distilled
[chyph]water, and dry at 105 [deg]C for 1 h before use.
5.2 Purge and trap system--The purge and trap system consists of
three separate pieces of equipment: A purging device, trap, and
desorber. Several complete systems are now commercially available.
5.2.1 The purging device must be designed to accept 5-mL samples
with a water column at least 3 cm deep. The gaseous head space between
the water column and the trap must have a total volume of less than 15
mL. The purge gas must pass through the water column as finely divided
bubbles with a diameter of less than 3 mm at the origin. The purge gas
must be introduced no more than 5 mm from the base of the water column.
The purging device illustrated in Figure 1 meets these design criteria.
5.2.2 The trap must be at least 25 cm long and have an inside
diameter of at least 0.105 in.
5.2.2.1 The trap is packed with 1 cm of methyl silicone coated
packing (Section 6.4.2) and 23 cm of 2,6-diphenylene oxide polymer
(Section 6.4.1) as shown in Figure 2. This trap was used to develop the
method performance statements in Section 12.
5.2.2.2 Alternatively, either of the two traps described in Method
601 may be used, although water vapor will preclude the measurement of
low concentrations of benzene.
5.2.3 The desorber must be capable of rapidly heating the trap to
180 [deg]C. The polymer section of the trap should not be heated higher
than 180 [deg]C and the remaining sections should not exceed 200 [deg]C.
The desorber illustrated in Figure 2 meets these design criteria.
5.2.4 The purge and trap system may be assembled as a separate unit
or be coupled to a gas chromatograph as illustrated in Figures 3, 4, and
5.
5.3 Gas chromatograph--An analytical system complete with a
temperature programmable gas chromatograph suitable for on-column
injection and all required accessories including syringes, analytical
columns, gases, detector, and strip-chart recorder. A data system is
recommended for measuring peak areas.
5.3.1 Column 1--6 ft long x 0.082 in. ID stainless steel or glass,
packed with 5% SP-1200 and 1.75% Bentone-34 on Supelcoport (100/120
mesh) or equivalent. This column was used to develop the method
performance statements in Section 12. Guidelines for the use of
alternate column packings are provided in Section 10.1.
5.3.2 Column 2--8 ft long x 0.1 in ID stainless steel or glass,
packed with 5% 1,2,3-Tris(2-cyanoethoxy)propane on Chromosorb W-AW (60/
80 mesh) or equivalent.
5.3.3 Detector--Photoionization detector (h-Nu Systems, Inc. Model
PI-51-02 or equivalent). This type of detector has been proven effective
in the analysis of wastewaters for the parameters listed in the scope
(Section 1.1), and was used to develop the method performance statements
in Section 12. Guidelines for the use of alternate detectors are
provided in Section 10.1.
5.4 Syringes--5-mL glass hypodermic with Luerlok tip (two each), if
applicable to the purging device.
5.5 Micro syringes--25-[mu]L, 0.006 in. ID needle.
5.6 Syringe valve--2-way, with Luer ends (three each).
5.7 Bottle--15-mL, screw-cap, with Teflon cap liner.
5.8 Balance--Analytical, capable of accurately weighing 0.0001 g.

6. Reagents

6.1 Reagent water--Reagent water is defined as a water in which an
interferent is not observed at the MDL of the parameters of interest.
6.1.1 Reagent water can be generated by passing tap water through a
carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-
300, Calgon Corp., or equivalent).
6.1.2 A water purification system (Millipore Super-Q or equivalent)
may be used to generate reagent water.
6.1.3 Reagent water may also be prepared by boiling water for 15
min. Subsequently, while maintaining the temperature at 90 [deg]C,
bubble a contaminant-free inert gas through the water for 1 h. While
still hot, transfer the water to a narrow mouth screw-cap bottle and
seal with a Teflon-lined septum and cap.
6.2 Sodium thiosulfate--(ACS) Granular.
6.3 Hydrochloric acid (1+1)--Add 50 mL of concentrated HCl (ACS) to
50 mL of reagent water.
6.4 Trap Materials:

[[Page 54]]

6.4.1 2,6-Diphenylene oxide polymer--Tenax, [chyph](60/80 mesh),
chromatographic grade or equiv[chyph]alent.
6.4.2 Methyl silicone packing--3% OV-1 on Chromosorb-W (60/80 mesh)
or equivalent.
6.5 Methanol--Pesticide quality or equivalent.
6.6 Stock standard solutions--Stock stand[chyph]ard solutions may be
prepared from pure [chyph]standard materials or purchased as certified
[chyph]solutions. Prepare stock standard solutions in [chyph]methanol
using assayed liquids. Because [chyph]of the toxicity of benzene and
1,4-dichloro[chyph]benzene, primary dilutions of these mate[chyph]rials
should be prepared in a hood. A [chyph]NIOSH/MESA approved toxic gas
respirator should be used when the analyst handles high concentrations
of such materials.
6.6.1 Place about 9.8 mL of methanol into a 10-mL ground glass
stoppered volumetric flask. Allow the flask to stand, unstoppered, for
about 10 min or until all alcohol wetted surfaces have dried. Weigh the
flask to the nearest 0.1 mg.
6.6.2 Using a 100-[mu]L syringe, immediately add two or more drops
of assayed reference material to the flask, then reweigh. Be sure that
the drops fall directly into the alcohol without contacting the neck of
the flask.
6.6.3 Reweigh, dilute to volume, stopper, then mix by inverting the
flask several times. Calculate the concentration in [mu]g/[mu]L from the
net gain in weight. When compound purity is assayed to be 96% or
greater, the weight can be used without correction to calculate the
concentration of the stock standard. Commercially prepared stock
standards can be used at any concentration if they are certified by the
manufacturer or by an independent source.
6.6.4 Transfer the stock standard solution into a Teflon-sealed
screw-cap bottle. Store at 4 [deg]C and protect from light.
6.6.5 All standards must be replaced after one month, or sooner if
comparison with check standards indicates a problem.
6.7 Secondary dilution standards--Using stock standard solutions,
prepare secondary dilution standards in methanol that contain the
compounds of interest, either singly or mixed together. The secondary
dilution standards should be prepared at concentrations such that the
aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will
bracket the working range of the analytical system. Secondary solution
standards must be stored with zero headspace and should be checked
frequently for signs of degradation or evaporation, especially just
prior to preparing calibration standards from them.
6.8 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

7.1 Assemble a purge and trap system that meets the specifications
in Section 5.2. Condition the trap overnight at 180 [deg]C by
backflushing with an inert gas flow of at least 20 mL/min. Condition the
trap for 10 min once daily prior to use.
7.2 Connect the purge and trap system to a gas chromatograph. The
gas chromatograph must be operated using temperature and flow rate
conditions equivalent to those given in Table 1. Calibrate the purge and
trap-gas chromatographic system using either the external standard
technique (Section 7.3) or the internal standard technique (Section
7.4).
7.3 External standard calibration procedure:
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter by carefully adding 20.0 [mu]L
of one or more secondary dilution standards to 100, 500, or 1000 mL of
reagent water. A 25-[mu]L syringe with a 0.006 in. ID needle should be
used for this operation. One of the external standards should be at a
concentration near, but above, the MDL (Table 1) and the other
concentrations should correspond to the expected range of concentrations
found in real samples or should define the working range of the
detector. These aqueous standards must be prepared fresh daily.
7.3.2 Analyze each calibration standard according to Section 10, and
tabulate peak height or area responses versus the concentration in the
standard. The results can be used to prepare a calibration curve for
each compound. Alternatively, if the ratio of response to concentration
(calibration factor) is a constant over the working range (<10% relative
standard deviation, RSD), linearity through the origin can be assumed
and the average ratio or calibration factor can be used in place of a
calibration curve.
7.4 Internal standard calibration procedure--To use this approach,
the analyst must select one or more internal standards that are similar
in analytical behavior to the compounds of interest. The analyst must
further demonstrate that the measurement of the internal standard is not
affected by method or matrix interferences. Because of these
limitations, no internal standard can be suggested that is applicable to
all samples. The compound, [alpha],[alpha],[alpha],-trifluorotoluene,
recommended as a surrogate spiking compound in Section 8.7 has been used
successfully as an internal standard.
7.4.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest as described in
Section 7.3.1.
7.4.2 Prepare a spiking solution containing each of the internal
standards using the procedures described in Sections 6.6 and 6.7. It is
recommended that the secondary dilution standard be prepared at a
concentration of 15 [mu]g/mL of each internal standard compound. The
addition of 10 [mu]l of this

[[Page 55]]

standard to 5.0 mL of sample or calibration standard would be equivalent
to 30 [mu]g/L.
7.4.3 Analyze each calibration standard according to Section 10,
adding 10 [mu]L of internal standard spiking solution directly to the
syringe (Section 10.4). Tabulate peak height or area responses against
concentration for each compound and internal standard, and calculate
response factors (RF) for each compound using Equation 1.

RF= (As)(Cis) (Ais)(Cs)
----------------------------------------------------------------------------------------------------------------

Equation 1

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Cis=Concentration of the internal standard
Cs=Concentration of the parameter to be measured.

8. Quality Control

8.1 Each laboratory that uses this method is required to operate a
formal quality control program. The mimimum requirements of this program
consist of an initial demonstration of laboratory capability and an
ongoing analysis of spiked samples to evaluate and document data
quality. The laboratory must maintain records to document the quality of
data that is generated. Ongoing data quality checks are compared with
established performance criteria to determine if the results of analyses
meet the performance characteristics of the method. When results of
sample spikes indicate atypical method performance, a quality control
check standard must be analyzed to confirm that the measurements were
performed in an in-control mode of operation.
8.1.1 The analyst must make an initial, one-time, demonstration of
the ability to generate acceptable accuracy and precision with this
method. This ability is established as described in Section 8.2.
8.1.2 In recognition of advances that are occurring in
chromatography, the analyst is permitted certain options (detailed in
Section 10.1) to improve the separations or lower the cost of
measurements. Each time such a modification is made to the method, the
analyst is required to repeat the procedure in Section 8.2.
8.1.3 Each day, the analyst must analyze a reagent water blank to
demonstrate that interferences from the analytical system are under
control.
8.1.4 The laboratory must, on an ongoing basis, spike and analyze a
minimum of 10% of all samples to monitor and evaluate laboratory data
quality. This procedure is described in Section 8.3.
8.1.5 The laboratory must, on an ongoing basis, demonstrate through
the analyses of quality control check standards that the operation of
the measurement system is in control. This procedure is described in
Section 8.4. The frequency of the check standard analyses is equivalent
to 10% of all samples analyzed but may be reduced if spike recoveries
from samples (Section 8.3) meet all specified quality control criteria.
8.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is described in
Section 8.5.
8.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
8.2.1 A quality control (QC) check sample concentrate is required
containing each parameter of interest at a concentration of 10 [mu]g/mL
in methanol. The QC check sample concentrate must be obtained from the
U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory in Cincinnati, Ohio, if available. If not available
from that source, the QC check sample concentrate must be obtained from
another external source. If not available from either source above, the
QC check sample concentrate must be prepared by the laboratory using
stock standards prepared independently from those used for calibration.
8.2.2 Prepare a QC check sample to contain 20 [mu]g/L of each
parameter by adding 200 [mu]L of QC check sample concentrate to 100 mL
of reagant water.
8.2.3 Analyze four 5-mL aliquots of the well-mixed QC check sample
according to Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter of
interest using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria

[[Page 56]]

for precision and accuracy, respectively, found in Table 2. If s and X
for all parameters of interest meet the acceptance criteria, the system
performance is acceptable and analysis of actual samples can begin. If
any individual s exceeds the precision limit or any individual X falls
outside the range for accuracy, the system performance is unacceptable
for that parameter.
Note: The large number of parameters in Table 2 present a
substantial probability that one or more will fail at least one of the
acceptance criteria when all parameters are analyzed.
8.2.6 When one or more of the parameters tested fail at least one of
the acceptance criteria, the analyst must proceed according to Section
8.2.6.1 or 8.2.6.2.
8.2.6.1 Locate and correct the source of the problem and repeat the
test for all parameters of interest beginning with Section 8.2.3.
8.2.6.2 Beginning with Section 8.2.3, repeat the test only for those
parameters that failed to meet criteria. Repeated failure, however, will
confirm a general problem with the measurement system. If this occurs,
locate and correct the source of the problem and repeat the test for all
compounds of interest beginning with Section 8.2.3.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at 20 [mu]g/L or 1 to 5 times higher than the background
concentration determined in Section 8.3.2, whichever concentration would
be larger.
8.3.2 Analyze one 5-mL sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second 5-mL sample aliquot with 10
[mu]L of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100(A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 2. These acceptance
criteria were calculated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.\7\ If spiking was performed at a concentration lower than 20 [mu]g/
L, the analyst must use either the QC acceptance criteria in Table 2, or
optional QC acceptance criteria calculated for the specific spike
concentration. To calculate optional acceptance criteria for the
recovery of a parameter: (1) Calculate accuracy (X') using the equation
in Table 3, substituting the spike concentration (T) for C; (2)
calculate overall precision (S') using the equation in Table 3,
substituting X' for X; (3) calculate the range for recovery at the spike
concentration as (100 X'/T) +-2.44(100 S'/T)%.\7\
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory.
8.4.1 Prepare the QC check standard by adding 10 [mu]L of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent water.
The QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
2. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P)

[[Page 57]]

and the standard deviation of the percent recovery (sp).
Express the accuracy assessment as a percent recovery interval from P-
2sp to P+2sp. If P=90% and sp=10%, for
example, the accuracy interval is expressed as 70-110%. Update the
accuracy assessment for each parameter on a regular basis (e.g. after
each five to ten new accuracy measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates may be analyzed to assess the
precision of the environmental measurements. When doubt exists over the
identification of a peak on the chromatogram, confirmatory techniques
such as gas chromatography with a dissimilar column, specific element
detector, or mass spectrometer must be used. Whenever possible, the
laboratory should analyze standard reference materials and participate
in relevant performance evaluation studies.
8.7 The analyst should monitor both the performance of the
analytical system and the effectiveness of the method in dealing with
each sample matrix by spiking each sample, standard, and reagent water
blank with surrogate compounds (e.g. [alpha], [alpha], [alpha],-
trifluorotoluene) that encompass the range of the temperature program
used in this method. From stock standard solutions prepared as in
Section 6.6, add a volume to give 750 [mu]g of each surrogate to 45 mL
of reagent water contained in a 50-mL volumetric flask, mix and dilute
to volume for a concentration of 15 mg/[mu]L. Add 10 [mu]L of this
surrogate spiking solution directly into the 5-mL syringe with every
sample and reference standard analyzed. Prepare a fresh surrogate
spiking solution on a weekly basis. If the internal standard calibration
procedure is being used, the surrogate compounds may be added directly
to the internal standard spiking solution (Section 7.4.2).

9. Sample Collection, Preservation, and Handling

9.1 The samples must be iced or refrigerated from the time of
collection until analysis. If the sample contains free or combined
chlorine, add sodium thiosulfate preservative (10 mg/40 mL is sufficient
for up to 5 ppm Cl2) to the empty sample bottle just prior to
shipping to the sampling site. EPA Method 330.4 or 330.5 may be used for
measurement of residual chlorine.⁸ Field test kits are
available for this purpose.
9.2 Collect about 500 mL of sample in a clean container. Adjust the
pH of the sample to about 2 by adding 1+1 HCl while stirring. Fill the
sample bottle in such a manner that no air bubbles pass through the
sample as the bottle is being filled. Seal the bottle so that no air
bubbles are entrapped in it. Maintain the hermetic seal on the sample
bottle until time of analysis.
9.3 All samples must be analyzed within 14 days of
collection.³

10. Procedure

10.1 Table 1 summarizes the recommended operating conditions for the
gas chrom[chyph]atograph. Included in this table [chyph]are estimated
retention times and MDL [chyph]that can be achieved under these
conditions. An ex[chyph]ample of the separations achieved by Column 1 is
shown in Figure 6. Other packed columns, chromatographic conditions, or
detectors may be used if the requirements of Section 8.2 are met.
10.2 Calibrate the system daily as described in Section 7.
10.3 Adjust the purge gas (nitrogen or helium) flow rate to 40 mL/
min. Attach the trap inlet to the purging device, and set the purge and
trap system to purge (Figure 3). Open the syringe valve located on the
purging device sample introduction needle.
10.4 Allow the sample to come to ambient temperature prior to
introducing it to the syringe. Remove the plunger from a 5-mL syringe
and attach a closed syringe valve. Open the sample bottle (or standard)
and carefully pour the sample into the syringe barrel to just short of
overflowing. Replace the syringe plunger and compress the sample. Open
the syringe valve and vent any residual air while adjusting the sample
volume to 5.0 mL. Since this process of taking an aliquot destroys the
validity of the sample for future analysis, the analyst should fill a
second syringe at this time to protect against possible loss of data.
Add 10.0 [mu]L of the surrogate spiking solution (Section 8.7) and 10.0
[mu]L of the internal standard spiking solution (Section 7.4.2), if
applicable, through the valve bore, then close the valve.
10.5 Attach the syringe-syringe valve assembly to the syringe valve
on the purging device. Open the syringe valves and inject the sample
into the purging chamber.
10.6 Close both valves and purge the sample for 12.0+-0.1 min at
ambient temperature.
10.7 After the 12-min purge time, disconnect the purging device from
the trap. Dry the trap by maintaining a flow of 40 mL/min of dry purge
gas through it for 6 min (Figure 4). If the purging device has no
provision for bypassing the purger for this step, a dry purger should be
inserted into the device to minimize moisture in the gas. Attach the
trap to the chromatograph, adjust the purge and trap system to the
desorb mode (Figure 5), and begin to temperature program the gas
chromatograph. Introduce the trapped materials to the GC column by
rapidly heating the trap to 180 [deg]C while backflushing the trap with
an inert gas between 20 and 60 mL/min for 4 min. If rapid heating of the
trap cannot be achieved, the GC column must be used as

[[Page 58]]

a secondary trap by cooling it to 30 [deg]C (subambient temperature, if
poor peak geometry and random retention time problems persist) instead
of the initial program temperature of 50 [deg]C.
10.8 While the trap is being desorbed into the gas chromatograph
column, empty the purging chamber using the sample introduction syringe.
Wash the chamber with two 5-mL flushes of reagent water.
10.9 After desorbing the sample for 4 min, recondition the trap by
returning the purge and trap system to the purge mode. Wait 15 s, then
close the syringe valve on the purging device to begin gas flow through
the trap. The trap temperature should be maintained at 180 [deg]C. After
approximately 7 min, turn off the trap heater and open the syringe valve
to stop the gas flow through the trap. When the trap is cool, the next
sample can be analyzed.
10.10 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. [chyph]The width of the retention
time window used to make identifications should be based upon
measurements of actual retention time variations of standards over the
course of a day. Three times the standard deviation of a retention time
for a compound can be used to calculate a suggested window size;
however, the experience of the analyst should weigh heavily in the
interpretation of chromatograms.
10.11 If the response for a peak exceeds the working range of the
system, prepare a dilution of the sample with reagent water from the
aliquot in the second syringe and reanalyze.

11. Calculations

Equation 2
where:
As = Response for the parameter to be measured.
Ais = Response for the internal standard.
Cis = Concentration of the internal standard.

11.2 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

12. Method Performance

12.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and reported with 99%
confidence that the value is above zero.¹ The MDL
concentrations listed in Table 1 were obtained using reagent
water.⁹ Similar results were achieved using representative
wastewaters. The MDL actually achieved in a given analysis will vary
depending on instrument sensitivity and matrix effects.
12.2 This method has been demonstrated to be applicable for the
concentration range from the MDL to 100 x MDL.⁹ Direct
aqueous injection techniques should be used to measure concentration
levels above 1000 x MDL.
12.3 This method was tested by 20 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
at six concentrations over the range 2.1 to 550 [mu]g/L.⁹
Single operator precision, overall precision, and method accuracy were
found to be directly related to the concentration of the parameter and
essentially independent of the sample matrix. Linear equations to
describe these relationships are presented in Table 3.

References

1. 40 CFR part 136, appendix B.
2. Lichtenberg, J.J. ``Determining Volatile Organics at Microgram-
per-Litre-Levels by Gas Chromatography,'' Journal American Water Works
Association, 66, 739 (1974).
3. Bellar, T.A., and Lichtenberg, J.J. ``Semi-Automated Headspace
Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile
Organic Compounds,'' Proceedings of Symposium on Measurement of Organic
Pollutants in Water and Wastewater. American Society for Testing and
Materials, STP 686, C.E. Van Hall, editor, 1978.
4. ``Carcinogens--Working with Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health.
Publication No. 77-206, August 1977.
5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
6. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Safety, 3rd Edition, 1979.
7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3. is two times the value 1.22
derived in this report.)

[[Page 59]]

8.``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S.
Environmental Protection Agency, Office of Research and Development,
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268.
March 1979.
9. ``EPA Method Study 25, Method 602, Purgeable Aromatics,'' EPA
600/4-84-042, National Technical Information Service, PB84-196682,
Springfield, Virginia 22161, May 1984.

Table 1--Chromatographic Conditions and Method Detection Limits
------------------------------------------------------------------------
Retention time (min) Method
---------------------- detection
Parameter limit
Column 1 Column 2 ([mu]g/L)
------------------------------------------------------------------------
Benzene................................ 3.33 2.75 0.2
Toluene................................ 5.75 4.25 0.2
Ethylbenzene........................... 8.25 6.25 0.2
Chlorobenzene.......................... 9.17 8.02 0.2
1,4-Dichlorobenzene.................... 16.8 16.2 0.3
1,3-Dichlorobenzene.................... 18.2 15.0 0.4
1,2-Dichlorobenzene.................... 25.9 19.4 0.4
------------------------------------------------------------------------
Column 1 conditions: Supelcoport (100/120 mesh) coated with 5% SP-1200/
1.75% Bentone-34 packed in a 6 ft x 0.085 in. ID stainless steel
column with helium carrier gas at 36 mL/min flow rate. Column
temperature held at 50 [deg]C for 2 min then programmed at 6 [deg]C/
min to 90 [deg]C for a final hold.
Column 2 conditions: Chromosorb W-AW (60/80 mesh) coated with 5% 1,2,3-
Tris(2-cyanoethyoxy)propane packed in a 6 ft x 0.085 in. ID stainless
steel column with helium carrier gas at 30 mL/min flow rate. Column
temperature held at 40 [deg]C for 2 min then programmed at 2 [deg]C/
min to 100 [deg]C for a final hold.

Table 2--Calibration and QC Acceptance Criteria--Method 602 a
----------------------------------------------------------------------------------------------------------------
Limit
Range for Q for s Range for X Range for
Parameter ([mu]g/L) ([mu]g/ ([mu]g/L) P, Ps(%)
L)
----------------------------------------------------------------------------------------------------------------
Benzene.......................................................... 15.4-24.6 4.1 10.0-27.9 39-150
Chlorobenzene.................................................... 16.1-23.9 3.5 12.7-25.4 55-135
1,2-Dichlorobenzene.............................................. 13.6-26.4 5.8 10.6-27.6 37-154
1,3-Dichlorobenzene.............................................. 14.5-25.5 5.0 12.8-25.5 50-141
1,4-Dichlorobenzene.............................................. 13.9-26.1 5.5 11.6-25.5 42-143
Ethylbenzene..................................................... 12.6-27.4 6.7 10.0-28.2 32-160
Toluene.......................................................... 15.5-24.5 4.0 11.2-27.7 46-148
----------------------------------------------------------------------------------------------------------------
Q=Concentration measured in QC check sample, in [mu]g/L (Section 7.5.3).
s=Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
Ps, P=Percent recovery measured (Section 8.3.2, Section 8.4.2).
a Criteria were calculated assuming a QC check sample concentration of 20 [mu]g/L.

Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the
limits for recovery have been broadened to assure applicability of the limits to concentrations below those
used to develop Table 3.

Table 3--Method Accuracy and Precision as Functions of Concentration--Method 602
----------------------------------------------------------------------------------------------------------------
Accuracy, as Single analyst Overall
Parameter recovery, X' precision, s' precision, S'
([mu]g/L) ([mu]g/L) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
Benzene......................................................... 0.92C+0.57 0.09X+0.59 0.21X+0.56
Chlorobenzene................................................... 0.95C+0.02 0.09X+0.23 0.17X+0.10
1,2-Dichlorobenzene............................................. 0.93C+0.52 0.17X-0.04 0.22X+0.53
1,3-Dichlorobenzene............................................. 0.96C-0.05 0.15X-0.10 0.19X+0.09
1,4-Dichlorobenzene............................................. 0.93C-0.09 0.15X+0.28 0.20X+0.41
Ethylbenzene.................................................... 0.94C+0.31 0.17X+0.46 0.26X+0.23
Toluene......................................................... 0.94C+0.65 0.09X+0.48 0.18X+0.71
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
S'=Expected single analyst standard deviation of measurements at an average concentration found of X, in X [mu]g/
L.
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
C=True value for the Concentration, in [mu]g/L.
X=Average recovery found for measurements of samples containing a concentration of C, in [mu]g/L.

[[Page 60]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.004

[[Page 61]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.005

[[Page 62]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.006

[[Page 63]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.007

[[Page 64]]

Method 603--Acrolein and Acrylonitrile

1. Scope and Application

1.1 This method covers the determination of acrolein and
acrylonitrile. The following parameters may be determined by this
method:

1.2 This is a purge and trap gas chromatographic (GC) method
applicable to the determination of the compounds listed above in
municipal and industrial discharges as provided under 40 CFR 136.1. When
this method is used to analyze unfamiliar samples for either or both of
the compounds above, compound identifications should be supported by at
least one additional qualitative technique. This method describes
analytical conditions for a second gas chromatographic column that can
be used to confirm measurements made with the primary column. Method 624
provides gas chromatograph/mass spectrometer (GC/MS) conditions
appropriate for the qualitative and quantitative confirmation of results
for the parameters listed above, if used with the purge and trap
conditions described in this method.
1.3 The method detection limit (MDL, defined in Section 12.1)
¹ for each parameter is listed in Table 1. The MDL for a
specific wastewater may differ from those listed, depending upon the
nature of interferences in the sample matrix.
1.4 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.5 This method is restricted to use by or under the supervision of
analysts experienced in the operation of a purge and trap system and a
gas chromatograph and in the interpretation of gas chromatograms. Each
analyst must demonstrate the ability to generate acceptable results with
this method using the procedure described in Section 8.2.

2. Summary of Method

2.1 An inert gas is bubbled through a 5-mL water sample contained in
a heated purging chamber. Acrolein and acrylonitrile are transferred
from the aqueous phase to the vapor phase. The vapor is swept through a
sorbent trap where the analytes are trapped. After the purge is
completed, the trap is heated and backflushed with the inert gas to
desorb the compound onto a gas chromatographic column. The gas
chromatograph is temperature programmed to separate the analytes which
are then detected with a flame ionization detector.^{2, 3}
2.2 The method provides an optional gas chromatographic column that
may be helpful in resolving the compounds of interest from the
interferences that may occur.

3. Interferences

3.1 Impurities in the purge gas and organic compound outgassing from
the plumbing of the trap account for the majority of contamination
problems. The analytical system must be demonstrated to be free from
contamination under the conditions of the analysis by running laboratory
reagent blanks as described in Section 8.1.3. The use of non-Teflon
plastic tubing, non-Teflon thread sealants, or flow controllers with
rubber components in the purge and trap system should be avoided.
3.2 Samples can be contaminated by diffusion of volatile organics
through the septum seal into the sample during shipment and storage. A
field reagent blank prepared from reagent water and carried through the
sampling and handling protocol can serve as a check on such
contamination.
3.3 Contamination by carry-over can occur whenever high level and
low level samples are sequentially analyzed. To reduce carry-over, the
purging device and sample syringe must be rinsed between samples with
reagent water. Whenever an unusually concentrated sample is encountered,
it should be followed by an analysis of reagent water to check for cross
contamination. For samples containing large amounts of water-soluble
materials, suspended solids, high boiling compounds or high analyte
levels, it may be necessary to wash the purging device with a detergent
solution, rinse it with distilled water, and then dry it in an oven at
105 [deg]C between analyses. The trap and other parts of the system are
also subject to contamination, therefore, frequent bakeout and purging
of the entire system may be required.

4. Safety

[[Page 65]]

5. Apparatus and Materials

5.1 Sampling equipment, for discrete sampling.
5.1.1 Vial--25-mL capacity or larger, equipped with a screw cap with
a hole in the center (Pierce 13075 or equivalent). Detergent
wash, rinse with tap and distilled water, and dry at 105 [deg]C before
use.
5.1.2 Septum--Teflon-faced silicone (Pierce 12722 or
equivalent). Detergent wash, rinse with tap and distilled water and dry
at 105 [deg]C for 1 h before use.
5.2 Purge and trap system--The purge and trap system consists of
three separate pieces of equipment: a purging device, trap, and
desorber. Several complete systems are now commercially available.
5.2.1 The purging device must be designed to accept 5-mL, samples
with a water column at least 3 cm deep. The gaseous head space between
the water column and the trap must have a total volume of less than 15
mL. The purge gas must pass through the water column as finely divided
bubbles with a diameter of less than 3 mm at the origin. The purge gas
must be introduced no more than 5 mm from the base of the water column.
The purging device must be capable of being heated to 85 [deg]C within
3.0 min after transfer of the sample to the purging device and being
held at 85 +-2 [deg]C during the purge cycle. The entire water column in
the purging device must be heated. Design of this modification to the
standard purging device is optional, however, use of a water bath is
suggested.
5.2.1.1 Heating mantle--To be used to heat water bath.
5.2.1.2 Temperature controller--Equipped with thermocouple/sensor to
accurately control water bath temperature to +-2 [deg]C. The purging
device illustrated in Figure 1 meets these design criteria.
5.2.2 The trap must be at least 25 cm long and have an inside
diameter of at least 0.105 in. The trap must be packed to contain 1.0 cm
of methyl silicone coated packing (Section 6.5.2) and 23 cm of 2,6-
diphenylene oxide polymer (Section 6.5.1). The minimum specifications
for the trap are illustrated in Figure 2.
5.2.3 The desorber must be capable of rapidly heating the trap to
180 [deg]C, The desorber illustrated in Figure 2 meets these design
criteria.
5.2.4 The purge and trap system may be assembled as a separate unit
as illustrated in Figure 3 or be coupled to a gas chromatograph.
5.3 pH paper--Narrow pH range, about 3.5 to 5.5 (Fisher Scientific
Short Range Alkacid No. 2, 14-837-2 or equivalent).
5.4 Gas chromatograph--An analytical system complete with a
temperature programmable gas chromatograph suitable for on-column
injection and all required accessories including syringes, analytical
columns, gases, detector, and strip-chart recorder. A data system is
recommended for measuring peak areas.
5.4.1 Column 1--10 ft long x 2 mm ID glass or stainless steel,
packed with Porapak-QS (80/100 mesh) or equivalent. This column was used
to develop the method performance statements in Section 12. Guidelines
for the use of alternate column packings are provided in Section 10.1.
5.4.2 Column 2--6 ft long x 0.1 in. ID glass or stainless steel,
packed with Chromosorb 101 (60/80 mesh) or equivalent.
5.4.3 Detector--Flame ionization detector. This type of detector has
proven effective in the analysis of wastewaters for the parameters
listed in the scope (Section 1.1), and was used to develop the method
performance statements in Section 12. Guidelines for the use of
alternate detectors are provided in Section 10.1.
5.5 Syringes--5-mL, glass hypodermic with Luerlok tip (two each).
5.6 Micro syringes--25-[mu]L, 0.006 in. ID needle.
5.7 Syringe valve--2-way, with Luer ends (three each).
5.8 Bottle--15-mL, screw-cap, with Teflon cap liner.
5.9 Balance--Analytical, capable of accurately weighing 0.0001 g.

6. Reagents

6.1 Reagent water--Reagent water is defined as a water in which an
interferent is not observed at the MDL of the parameters of interest.
6.1.1 Reagent water can be generated by passing tap water through a
carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-
300, Calgon Corp., or equivalent).
6.1.2 A water purification system (Millipore Super-Q or equivalent)
may be used to generate reagent water.
6.1.3 Regent water may also be prepared by boiling water for 15 min.
Subsequently, while maintaining the temperature at 90 [deg]C, bubble a
contaminant-free inert gas through the water for 1 h. While still hot,
transfer the water to a narrow mouth screw-cap bottle and seal with a
Teflon-lined septum and cap.
6.2 Sodium thiosulfate--(ACS) Granular.
6.3 Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) in
reagent water and dilute to 100 mL.
6.4 Hydrochloric acid (1+1)--Slowly, add 50 mL of concentrated HCl
(ACS) to 50 mL of reagent water.
6.5 Trap Materials:
6.5.1 2,6-Diphenylene oxide polymer--Tenax (60/80 mesh),
chromatographic grade or equivalent.
6.5.2 Methyl silicone packing--3% OV-1 on Chromosorb-W (60/80 mesh)
or equivalent.

[[Page 66]]

6.6 Stock standard solutions--Stock standard solutions may be
prepared from pure standard materials or purchased as certified
solutions. Prepare stock standard solutions in reagent water using
assayed liquids. Since acrolein and acrylonitrile are lachrymators,
primary dilutions of these compounds should be prepared in a hood. A
NIOSH/MESA approved toxic gas respirator should be used when the analyst
handles high concentrations of such materials.
6.6.1 Place about 9.8 mL of reagent water into a 10-mL ground glass
stoppered volumetric flask. For acrolein standards the reagent water
must be adjusted to pH 4 to 5. Weight the flask to the nearest 0.1 mg.
6.6.2 Using a 100-[mu]L syringe, immediately add two or more drops
of assayed reference material to the flask, then reweigh. Be sure that
the drops fall directly into the water without contacting the neck of
the flask.
6.6.3 Reweigh, dilute to volume, stopper, then mix by inverting the
flask several times. Calculate the concentration in [mu]g/[mu]L from the
net gain in weight. When compound purity is assayed to be 96% or
greater, the weight can be used without correction to calculate the
concentration of the stock staldard. Optionally, stock standard
solutions may be prepared using the pure standard material by
volumetrically measuring the appropriate amounts and determining the
weight of the material using the density of the material. Commercially
prepared stock standards may be used at any concentration if they are
certified by the manufactaurer or by an independent source.
6.6.4 Transfer the stock standard solution into a Teflon-sealed
screw-cap bottle. Store at 4 [deg]C and protect from light.
6.6.5 Prepare fresh standards daily.
6.7 Secondary dilution standards--Using stock standard solutions,
prepare secondary dilution standards in reagent water that contain the
compounds of interest, either singly or mixed together. The secondary
dilution standards should be prepared at concentrations such that the
aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will
bracket the working range of the analytical system. Secondary dilution
standards should be prepared daily and stored at 4 [deg]C.
6.8 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

7.1 Assemble a purge and trap system that meets the specifications
in Section 5.2. Condition the trap overnight at 180 [deg]C by
backflushing with an inert gas flow of at least 20 mL/min. Condition the
trap for 10 min once daily prior to use.
7.2 Connect the purge and trap system to a gas chromatograph. The
gas chromatograph must be operated using temperature and flow rate
conditions equivalent to those given in Table 1. Calibrate the purge and
trap-gas chromatographic system using either the external standard
technique (Section 7.3) or the internal standard technique (Section
7.4).
7.3 External standard calibration procedure:
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter by carefully adding 20.0 [mu]L
of one or more secondary dilution standards to 100, 500, or 1000 mL of
reagent water. A 25-[mu]L syringe with a 0.006 in. ID needle should be
used for this operation. One of the external standards should be at a
concentration near, but above, the MDL and the other concentrations
should correspond to the expected range of concentrations found in real
samples or should define the working range of the detector. These
standards must be prepared fresh daily.
7.3.2 Analyze each calibration standard according to Section 10, and
tabulate peak height or area responses versus the concentration of the
standard. The results can be used to prepare a calibration curve for
each compound. Alternatively, if the ratio of response to concentration
(calibration factor) is a constant over the working range (< 10%
relative standard deviation, RSD), linearity through the origin can be
assumed and the average ratio or calibration factor can be used in place
of a calibration curve.
7.4 Internal standard calibration procedure--To use this approach,
the analyst must select one or more internal standards that are similar
in analytical behavior to the compounds of interest. The analyst must
further demonstrate that the measurement of the internal standard is not
affected by method or matrix interferences. Because of these
limitations, no internal standard can be suggested that is applicable to
all samples.
7.4.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest as described in
Section 7.3.1.
7.4.2 Prepare a spiking solution containing each of the internal
standards using the procedures described in Sections 6.6 and 6.7. It is
recommended that the secondary dilution standard be prepared at a
concentration of 15 [mu]g/mL of each internal standard compound. The
addition of 10 [mu]L of this standard to 5.0 mL of sample or calibration
standard would be equivalent to 30 [mu]g/L.
7.4.3 Analyze each calibration standard according to Section 10,
adding 10 [mu]L of internal standard spiking solution directly to the
syringe (Section 10.4). Tabulate peak height or area responses against
concentration for each compound and internal standard, and calculate
response factors (RF) for each compound using Equation 1.

[[Page 67]]

RF= (As)(Cis) (Ais)(Cs)
----------------------------------------------------------------------------------------------------------------

Equation 1

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Cis=Concentration of the internal standard.
Cs=Concentration of the parameter to be measured.

8. Quality Control

8.1 Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements of this program
consist of an initial demonstration of laboratory capability and an
ongoing analysis of spiked samples to evaluate and document data
quality. The laboratory must maintain records to document the quality of
data that is generated. Ongoing data quality checks are compared with
established performance criteria to determine if the results of analyses
meet the performance characteristics of the method. When results of
sample spikes indicate atypical method performance, a quality control
check standard must be analyzed to confirm that the measurements were
performed in an in-control mode of operation.
8.1.1 The analyst must make an initial, one-time, demonstration of
the ability to generate acceptable accuracy and precision with this
method. This ability is established as described in Section 8.2.
8.1.2 In recognition of advances that are occurring in
chromatography, the analyst is permitted certain options (detailed in
Section 10.1) to improve the separations or lower the cost of
measurements. Each time such a modification is made to the method, the
analyst is required to repeat the procedure in Section 8.2.
8.1.3 Each day, the analyst must analyze a reagent water blank to
demonstrate that interferences from the analytical system are under
control.
8.1.4 The laboratory must, on an ongoing basis, spike and analyze a
minimum of 10% of all samples to monitor and evaluate laboratory data
quality. This procedure is described in Section 8.3.
8.1.5 The laboratory must, on an ongoing basis, demonstrate through
the analyses of quality control check standards that the operation of
the measurement system is in control. This procedure is described in
Section 8.4. The frequency of the check standard analyses is equivalent
to 10% of all samples analyzed but may be reduced if spike recoveries
from samples (Section 8.3) meet all specified quality control criteria.
8.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is described in
Section 8.5.
8.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
8.2.1 A quality control (QC) check sample concentrate is required
containing each parameter of interest at a concentration of 25 [mu]g/mL
in reagent water. The QC check sample concentrate must be obtained from
the U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory in Cincinnati, Ohio, if available. If not available
from that source, the QC check sample concentrate must be obtained from
another external source. If not available from either source above, the
QC check sample concentrate must be prepared by the laboratory using
stock standards prepared independently from those used for calibration.
8.2.2 Prepare a QC check sample to contain 50 [mu]g/L of each
parameter by adding 200 [mu]L of QC check sample concentrate to 100 mL
of reagent water.
8.2.3 Analyze four 5-mL aliquots of the well-mixed QC check sample
according to Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter
using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively, found in
Table 3. If s and X for all parameters of interest meet the acceptance
criteria, the system performance is acceptable and analysis of actual
samples can begin. If either s exceeds the precision limit or X falls
outside the range for accuracy, the system performance is unacceptable
for that parameter. Locate and correct the source of the

[[Page 68]]

problem and repeat the test for each compound of interest.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at 50 [mu]g/L or 1 to 5 times higher than the background
concentration determined in Section 8.3.2, whichever concentration would
be larger.
8.3.2 Analyze one 5-mL sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second 5-mL sample aliquot with 10
[mu]L of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100(A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 3. These acceptance
criteria were calculated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.⁷
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory.
8.4.1 Prepare the QC check standard by adding 10 [mu]L of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent water.
The QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
3. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2sp to P+2sp.
If P=90% and sp=10%, for example, the accuracy interval is
expressed as 70-110%. Update the accuracy assessment for each parameter
on a regular basis (e.g. after each five to ten new accuracy
measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates may be analyzed to assess the
precision of the environmental measurements. When doubt exists over the
identification of a peak on the chromatogram, confirmatory techniques
such as gas chromatography with a dissimilar column or mass spectrometer
must be used. Whenever possible, the laboratory should analyze standard
reference materials and participate in relevant performance evaluation
studies.

9. Sample Collection, Preservation, and Handling

[[Page 69]]

range pH paper. Samples for acrolein analysis receiving no pH adjustment
must be analyzed within 3 days of sampling.
9.3 Grab samples must be collected in glass containers having a
total volume of at least 25 mL. Fill the sample bottle just to
overflowing in such a manner that no air bubbles pass through the sample
as the bottle is being filled. Seal the bottle so that no air bubbles
are entrapped in it. If preservative has been added, shake vigorously
for 1 min. Maintain the hermetic seal on the sample bottle until time of
analysis.
9.4 All samples must be analyzed within 14 days of
collection.³

10. Procedure

10.1 Table 1 summarizes the recommended operating conditions for the
gas chromatograph. Included in this table are estimated retention times
and MDL that can be achieved under these conditions. An example of the
separations achieved by Column 1 is shown in Figure 5. Other packed
columns, chromatographic conditions, or detectors may be used if the
requirements of Section 8.2 are met.
10.2 Calibrate the system daily as described in Section 7.
10.3 Adjust the purge gas (nitrogen or helium) flow rate to 20 mL-
min. Attach the trap inlet to the purging device, and set the purge and
trap system to purge (Figure 3). Open the syringe valve located on the
purging device sample introduction needle.
10.4 Remove the plunger from a 5-mL syringe and attach a closed
syringe valve. Open the sample bottle (or standard) and carefully pour
the sample into the syringe barrel to just short of overflowing. Replace
the syringe plunger and compress the sample. Open the syringe valve and
vent any residual air while adjusting the sample volume to 5.0 mL. Since
this process of taking an aliquot destroys the validity of the sample
for future analysis, the analyst should fill a second syringe at this
time to protect against possible loss of data. Add 10.0 [mu]L of the
internal standard spiking solution (Section 7.4.2), if applicable,
through the valve bore then close the valve.
10.5 Attach the syringe-syringe valve assembly to the syringe valve
on the purging device. Open the syringe valves and inject the sample
into the purging chamber.
10.6 Close both valves and purge the sample for 15.0 +- 0.1 min
while heating at 85 +- 2 [deg]C.
10.7 After the 15-min purge time, attach the trap to the
chromatograph, adjust the purge and trap system to the desorb mode
(Figure 4), and begin to temperature program the gas chromatograph.
Introduce the trapped materials to the GC column by rapidly heating the
trap to 180 [deg]C while backflushing the trap with an inert gas between
20 and 60 mL/min for 1.5 min.
10.8 While the trap is being desorbed into the gas chromatograph,
empty the purging chamber using the sample introduction syringe. Wash
the chamber with two 5-mL flushes of reagent water.
10.9 After desorbing the sample for 1.5 min, recondition the trap by
returning the purge and trap system to the purge mode. Wait 15 s then
close the syringe valve on the purging device to begin gas flow through
the trap. The trap temperature should be maintained at 210 [deg]C. After
approximately 7 min, turn off the trap heater and open the syringe valve
to stop the gas flow through the trap. When the trap is cool, the next
sample can be analyzed.
10.10 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
can be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.

11. Calculations

Equation 2

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Cis=Concentration of the internal standard.

11.2 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

12. Method Performance

12.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and reported with 99%
confidence that the value is above

[[Page 70]]

zero.¹ The MDL concentrations listed in Table 1 were obtained
using reagent water.⁹ The MDL actually achieved in a given
analysis will vary depending on instrument sensitivity and matrix
effects.
12.2 This method is recommended for the concentration range from the
MDL to 1,000xMDL. Direct aqueous injection techniques should be used to
measure concentration levels above 1,000xMDL.
12.3 In a single laboratory (Battelle-Columbus), the average
recoveries and standard deviations presented in Table 2 were
obtained.⁹ Seven replicate samples were analyzed at each
spike level.

References

1. 40 CFR part 136, appendix B.
2. Bellar, T.A., and Lichtenberg, J.J. ``Determining Volatile
Organics at Microgram-per-Litre-Levels by Gas Chromatography,'' Journal
American Water Works Association, 66, 739 (1974).
3. ``Evaluate Test Procedures for Acrolein and Acrylonitrile,''
Special letter report for EPA Project 4719-A, U.S. Environmental
Protection Agency, Environmental Monitoring and Support Laboratory,
Cincinnati, Ohio 45268, 27 June 1979.
4. ``Carcinogens--Working With Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
6. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983).
8. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S.
Environmental Protection Agency, Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio 45268, March 1979.
9. ``Evaluation of Method 603 (Modified),'' EPA-600/4-84-ABC,
National Technical Information Service, PB84-, Springfield, Virginia
22161, Nov. 1984.

Table 1--Chromatographic Conditions and Method Detection Limits
------------------------------------------------------------------------
Retention time (min) Method
------------------------ detection
Parameter limit
Column 1 Column 2 ([mu]g/L)
------------------------------------------------------------------------
Acrolein............................ 10.6 8.2 0.7
Acrylonitrile....................... 12.7 9.8 0.5
------------------------------------------------------------------------
Column 1 conditions: Porapak-QS (80/100 mesh) packed in a 10 ft x 2 mm
ID glass or stainless steel column with helium carrier gas at 30 mL/
min flow rate. Column temperature held isothermal at 110 [deg]C for
1.5 min (during desorption), then heated as rapidly as possible to 150
[deg]C and held for 20 min; column bakeout at 190 [deg]C for 10
min.\9\
Column 2 conditions: Chromosorb 101 (60/80 mesh) packed in a 6 ft. x 0.1
in. ID glass or stainless steel column with helium carrier gas at 40
mL/min flow rate. Column temperature held isothermal at 80 [deg]C for
4 min, then programmed at 50 [deg]C/min to 120 [deg]C and held for 12
min.

Table 2--Single Laboratory Accuracy and Precision--Method 603
----------------------------------------------------------------------------------------------------------------
Spike
Sample conc. Average Standard Average
Parameter matrix ([mu]g/ recovery deviation percent
L) ([mu]g/L) ([mu]g/L) recovery
----------------------------------------------------------------------------------------------------------------
Acrolein................................................... RW 5.0 5.2 0.2 104
RW 50.0 51.4 0.7 103
POTW 5.0 4.0 0.2 80
POTW 50.0 44.4 0.8 89
IW 5.0 0.1 0.1 2
IW 100.0 9.3 1.1 9
Acrylonitrile.............................................. RW 5.0 4.2 0.2 84
RW 50.0 51.4 1.5 103
POTW 20.0 20.1 0.8 100
POTW 100.0 101.3 1.5 101
IW 10.0 9.1 0.8 91
IW 100.0 104.0 3.2 104
----------------------------------------------------------------------------------------------------------------
ARW=Reagent water.
APOTW=Prechlorination secondary effluent from a municipal sewage treatment plant.
AIW=Industrial wastewater containing an unidentified acrolein reactant.

Table 3--Calibration and QC Acceptance Criteria--Method 603 \a\
----------------------------------------------------------------------------------------------------------------
Limit for
Parameter Range for Q S ([mu]g/ Range for X Range for
([mu]g/L) L) ([mu]g/L) P, Ps (%)
----------------------------------------------------------------------------------------------------------------
Acrolein...................................................... 45.9-54.1 4.6 42.9-60.1 88-118

[[Page 71]]

Acrylonitrile................................................. 41.2-58.8 9.9 33.1-69.9 71-135
----------------------------------------------------------------------------------------------------------------
a=Criteria were calculated assuming a QC check sample concentration of 50 [mu]g/L.9
Q=Concentration measured in QC check sample, in [mu]g/L (Section 7.5.3).
s=Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).

[GRAPHIC] [TIFF OMITTED] TC02JY92.008

[[Page 72]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.009

[[Page 73]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.010

[[Page 74]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.011

Method 604--Phenols

1. Scope and Application

1.1 This method covers the determination of phenol and certain
substituted phenols. The following parameters may be determined by this
method:

------------------------------------------------------------------------
STORET
Parameter No. CAS No.
------------------------------------------------------------------------
4-Chloro-3-methylphenol.......................... 34452 59-50-7
2--Chlorophenol.................................. 34586 95-57-8
2,4-Dichlorophenol............................... 34601 120-83-2
2,4-Dimethylphenol............................... 34606 105-67-9
2,4-Dinitrophenol................................ 34616 51-28-5
2-Methyl-4,6-dinitrophenol....................... 34657 534-52-1
2-Nitrophenol.................................... 34591 88-75-5
4-Nitrophenol.................................... 34646 100-02-7
Pentachlorophenol................................ 39032 87-86-5
Phenol........................................... 34694 108-95-2
2,4,6-Trichlorophenol............................ 34621 88-06-2
------------------------------------------------------------------------

1.2 This is a flame ionization detector gas chromatographic (FIDGC)
method applicable to the determination of the compounds listed above in
municipal and industrial discharges as provided under 40 CFR 136.1. When
this method is used to analyze unfamiliar samples for any or all of the
compounds above, compound identifications should be supported by at
least one additional qualitative technique. This method describes
analytical conditions for derivatization, cleanup, and electron capture
detector gas chromatography (ECDGC) that can be used to confirm
measurements made by FIDGC. Method 625 provides gas chromatograph/mass
spectrometer (GC/MS) conditions appropriate for the qualitative and
quantitative confirmation of results for all of the parameters listed
above, using the extract produced by this method.
1.3 The method detection limit (MDL, defined in Section 14.1) \1\
for each parameter is listed in Table 1. The MDL for a specific
wastewater may differ from those listed, depending upon the nature of
interferences in the sample matrix. The MDL listed in Table 1 for each
parameter was achieved with a flame ionization detector (FID). The MDLs
that were achieved when the derivatization cleanup and electron capture
detector (ECD) were employed are presented in Table 2.

[[Page 75]]

1.4 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.5 This method is restricted to use by or under the supervision of
analysts experienced in the use of a gas chromatograph and in the
interpretation of gas chromatograms. Each analyst must demonstrate the
ability to generate acceptable results with this method using the
procedure described in Section 8.2.

2. Summary of Method

2.1 A measured volume of sample, approximately 1-L, is acidified and
extracted with methylene chloride using a separatory funnel. The
methylene chloride extract is dried and exchanged to 2-propanol during
concentration to a volume of 10 mL or less. The extract is separated by
gas chromatography and the phenols are then measured with an FID.\2\
2.2 A preliminary sample wash under basic conditions can be employed
for samples having high general organic and organic base interferences.
2.3 The method also provides for a derivatization and column
chromatography cleanup procedure to aid in the elimination of
interferences.^2,3 The derivatives are analyzed by ECDGC.

3. Interferences

3.1 Method interferences may be caused by contaminants in solvents,
reagents, glassware, and other sample processing hardware that lead to
discrete artifacts and/or elevated baselines in gas chromatograms. All
of these materials must be routinely demonstrated to be free from
interferences under the conditions of the analysis by running laboratory
reagent blanks as described in Section 8.1.3.
3.1.1 Glassware must be scrupulously cleaned.\4\ Clean all glassware
as soon as possible after use by rinsing with the last solvent used in
it. Solvent rinsing should be followed by detergent washing with hot
water, and rinses with tap water and distilled water. The glassware
should then be drained dry, and heated in a muffle furnace at 400 [deg]C
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not
be eliminated by this treatment. Solvent rinses with acetone and
pesticide quality hexane may be substituted for the muffle furnace
heating. Thorough rinsing with such solvents usually eliminates PCB
interference. Volumetric ware should not be heated in a muffle furnace.
After drying and cooling, glassware should be sealed and stored in a
clean environment to prevent any accumulation of dust or other
contaminants. Store inverted or capped with aluminum foil.
3.1.2 The use of high purity reagents and solvents helps to minimize
interference problems. Purification of solvents by distillation in all-
glass systems may be required.
3.2 Matrix interferences may be caused by contaminants that are
coextracted from the sample. The extent of matrix interferences will
vary considerably from source to source, depending upon the nature and
diversity of the industrial complex or municipality being sampled. The
derivatization cleanup procedure in Section 12 can be used to overcome
many of these interferences, but unique samples may require additional
cleanup approaches to achieve the MDL listed in Tables 1 and 2.
3.3 The basic sample wash (Section 10.2) may cause significantly
reduced recovery of phenol and 2,4-dimethylphenol. The analyst must
recognize that results obtained under these conditions are minimum
concentrations.

4. Safety

4.1 The toxicity or carcinogenicity of each reagent used in this
mothod has not been precisely defined; however, each chemical compound
should be treated as a potential health hazard. From this viewpoint,
exposure to these chemicals must be reduced to the lowest possible level
by whatever means available. The laboratory is responsible for
maintaining a current awareness file of OSHA regulations regarding the
safe handling of the chemicals specified in this method. A reference
file of material data handling sheets should also be made available to
all personnel involved in the chemical analysis. Additional references
to laboratory safety are available and have been identified
^5--7 for the information of analyst.
4.2 Special care should be taken in handling pentafluorobenzyl
bromide, which is a lachrymator, and 18-crown-6-ether, which is highly
toxic.

5. Apparatus and Materials

[[Page 76]]

used. Before use, however, the compressible tubing should be thoroughly
rinsed with methanol, followed by repeated rinsings with distilled water
to minimize the potential for contamination of the sample. An
integrating flow meter is required to collect flow proportional
composites.
5.2 Glassware (All specifications are suggested. Catalog numbers are
included for illustration only.):
5.2.1 Separatory funnel--2-L, with Teflon stopcock.
5.2.2 Drying column--Chromatographic column, 400 mm long x 19 mm ID,
with coarse frit filter disc.
5.2.3 Chromatographic column--100 mm long x 10 mm ID, with Teflon
stopcock.
5.2.4 Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes K-
570050-1025 or equivalent). Calibration must be checked at the volumes
employed in the test. Ground glass stopper is used to prevent
evaporation of extracts.
5.2.5 Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
5.2.6 Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
5.2.7 Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
5.2.8 Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
5.2.9 Reaction flask--15 to 25-mL round bottom flask, with standard
tapered joint, fitted with a water-cooled condenser and U-shaped drying
tube containing granular calcium chloride.
5.3 Boiling chips--Approximately 10/40 mesh. Heat to 400 [deg]C for
30 min or Soxhlet extract with methylene chloride.
5.4 Water bath--Heated, with concentric ring cover, capable of
temperature control (+-2[deg]C). The bath should be used in a hood.
5.5 Balance--Analytical, capable of accurately weighting 0.0001 g.
5.6 Gas chromatograph--An analytical system complete with a
temperature programmable gas chromatograph suitable for on-column
injection and all required accessories including syringes, analytical
columns, gases, detector, and strip-chart recorder. A data system is
recommended for measuring peak areas.
5.6.1 Column for underivatized phenols--1.8 m long x 2 mm ID glass,
packed with 1% SP-1240DA on Supelcoport (80/100 mesh) or equivalent.
This column was used to develop the method performance statements in
Section 14. Guidelines for the use of alternate column packings are
provided in Section 11.1.
5.6.2 Column for derivatized phenols--1.8 m long x 2 mm ID glass,
packed with 5% OV-17 on Chromosorb W-AW-DMCS (80/100 mesh) or
equivalent. This column has proven effective in the analysis of
wastewaters for derivatization products of the parameters listed in the
scope (Section 1.1), and was used to develop the method performance
statements in Section 14. Guidelines for the use of alternate column
packings are provided in Section 11.1.
5.6.3 Detectors--Flame ionization and electron capture detectors.
The FID is used when determining the parent phenols. The ECD is used
when determining the derivatized phenols. Guidelines for the use of
alternatve detectors are provided in Section 11.1.

6. Reagents

6.1 Reagent water--Reagent water is defined as a water in which an
interferent is not observed at the MDL of the parameters of interest.
6.2 Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) in
reagent water and dilute to 100 mL.
6.3 Sodium hydroxide solution (1 N)--Dissolve 4 g of NaOH (ACS) in
reagent water and dilute to 100 mL.
6.4 Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at
400[deg]C for 4 h in a shallow tray.
6.5 Sodium thiosulfate--(ACS) Granular.
6.6 Sulfuric acid (1+1)--Slowly, add 50 mL of
H2SO4 (ACS, sp. gr. 1.84) to 50 mL of reagent
water.
6.7 Sulfuric acid (1 N)--Slowly, add 58 mL of
H2SO4 (ACS, sp. gr. 1.84) to reagent water and
dilute to 1 L.
6.8 Potassium carbonate--(ACS) Powdered.
6.9 Pentafluorobenzyl bromide ([alpha]-Bromopentafluorotoluene)--97%
minimum purity.
Note: This chemical is a lachrymator. (See Section 4.2.)
6.10 18-crown-6-ether (1,4,7,10,13,16-Hexaoxacyclooctadecane)--98%
minimum purity.
Note: This chemical is highly toxic.
6.11 Derivatization reagent--Add 1 mL of pentafluorobenzyl bromide
and 1 g of 18-crown-6-ether to a 50-mL volumetric flask and dilute to
volume with 2-propanol. Prepare fresh weekly. This operation should be
carried out in a hood. Store at 4 [deg]C and protect from light.
6.12 Acetone, hexane, methanol, methylene chloride, 2-propanol,
toluene--Pesticide quality or equivalent.
6.13 Silica gel--100/200 mesh, Davison, grade-923 or equivalent.
Activate at 130 [deg]C overnight and store in a desiccator.
6.14 Stock standard solutions (1.00 [mu]g/[mu]L)--Stock standard
solutions may be prepared from pure standard materials or purchased as
certified solutions.
6.14.1 Prepare stock standard solutions by accurately weighing about
0.0100 g of pure material. Dissolve the material in 2-propanol

[[Page 77]]

and dilute to volume in a 10-mL volumetric flask. Larger volumes can be
used at the convenience of the analyst. When compound purity is assayed
to be 96% or greater, the weight can be used without correction to
calculate the concentration of the stock standard. Commercially prepared
stock standards can be used at any concentration if they are certified
by the manufacturer or by an independent source.
6.14.2 Transfer the stock standard solutions into Teflon-sealed
screw-cap bottles. Store at 4 [deg]C and protect from light. Stock
standard solutions should be checked frequently for signs of degradation
or evaporation, especially just prior to preparing calibration standards
from them.
6.14.3 Stock standard solutions must be replaced after six months,
or sooner if comparison with check standards indicates a problem.
6.15 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

7.1 To calibrate the FIDGC for the anaylsis of underivatized
phenols, establish gas chromatographic operating conditions equivalent
to those given in Table 1. The gas chromatographic system can be
calibrated using the external standard technique (Section 7.2) or the
internal standard technique (Section 7.3).
7.2 External standard calibration procedure for FIDGC:
7.2.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask and diluting to volume
with 2-propanol. One of the external standards should be at a
concentration near, but above, the MDL (Table 1) and the other
concentrations should correspond to the expected range of concentrations
found in real samples or should define the working range of the
detector.
7.2.2 Using injections of 2 to 5 [mu]l, analyze each calibration
standard according to Section 11 and tabulate peak height or area
responses against the mass injected. The results can be used to prepare
a calibration curve for each compound. Alternatively, if the ratio of
response to amount injected (calibration factor) is a constant over the
working range (<10% relative standard deviation, RSD), linearity through
the origin can be assumed and the average ratio or calibration factor
can be used in place of a calibration curve.
7.3 Internal standard calibration procedure for FIDGC--To use this
approach, the analyst must select one or more internal standards that
are similar in analytical behavior to the compounds of interest. The
analyst must further demonstrate that the measurement of the internal
standard is not affected by method or matrix interferences. Because of
these limitations, no internal standard can be suggested that is
applicable to all samples.
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask. To each calibration
standard, add a known constant amount of one or more internal standards,
and dilute to volume with 2-propanol. One of the standards should be at
a concentration near, but above, the MDL and the other concentrations
should correspond to the expected range of concentrations found in real
samples or should define the working range of the detector.
7.3.2 Using injections of 2 to 5 [mu]L, analyze each calibration
standard according to Section 11 and tabulate peak height or area
responses against concentration for each compound and internal standard.
Calculate response factors (RF) for each compound using Equation 1.

RF= (As)(Cis) (Ais)(Cs)
----------------------------------------------------------------------------------------------------------------

Equation 1

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Cis=Concentration of the internal standard ([mu]g/L).

Cs=Concentration of the parameter to be measured ([mu]g/L).

If the RF value over the working range is a constant (<10% RSD), the
RF can be assumed to be invariant and the average RF can be used for
calculations. Alternatively, the results can be used to plot a
calibration curve of response ratios, As/Ais, vs.
RF.
7.4 The working calibration curve, calibration factor, or RF must be
verified on each working day by the measurement of one or more
calibration standards. If the response for any parameter varies from the
predicted response by more than +-15%, a new calibration curve must be
prepared for that compound.
7.5 To calibrate the ECDGC for the analysis of phenol derivatives,
establish gas chromatographic operating conditions equivalent to those
given in Table 2.
7.5.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask and diluting to volume
with 2-propanol. One of the external standards should be at a
concentration near, but above, the MDL (Table 2) and the other
concentrations should correspond to the expected

[[Page 78]]

range of concentrations found in real samples or should define the
working range of the detector.
7.5.2 Each time samples are to be derivatized, simultaneously treat
a 1-mL aliquot of each calibration standard as described in Section 12.
7.5.3 After derivatization, analyze 2 to 5 [mu]L of each column
eluate collected according to the method beginning in Section 12.8 and
tabulate peak height or area responses against the calculated equivalent
mass of underivatized phenol injected. The results can be used to
prepare a calibration curve for each compound.
7.6 Before using any cleanup procedure, the analyst must process a
series of calibration standards through the procedure to validate
elution patterns and the absence of interferences from the reagents.

8. Quality Control

8.1 Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements of this program
consist of an initial demonstration of laboratory capability and an
ongoing analysis of spiked samples to evaluate and document data
quality. The laboratory must maintain records to document the quality of
data that is generated. Ongoing data quality checks are compared with
established performance criteria to determine if the results of analyses
meet the performance characteristics of the method. When results of
sample spikes indicate atypical method performance, a quality control
check standard must be analyzed to confirm that the measurements were
performed in an in-control mode of operation.
8.1.1 The analyst must make an initial, one-time, demonstration of
the ability to generate acceptable accuracy and precision with this
method. This ability is established as described in Section 8.2.
8.1.2 In recognition of advances that are occurring in
chromatography, the analyst is permitted certain options (detailed in
Sections 10.6 and 11.1) to improve the separations or lower the cost of
measurements. Each time such a modification is made to the method, the
analyst is required to repeat the procedure in Section 8.2.
8.1.3 Before processing any samples the analyst must analyze a
reagent water blank to demonstrate that interferences from the
analytical system and glassware are under control. Each time a set of
samples is extracted or reagents are changed a reagent water blank must
be processed as a safeguard against laboratory contamination.
8.1.4 The laboratory must, on an ongoing basis, spike and analyze a
minimum of 10% of all samples to monitor and evaluate laboratory data
quality. This procedure is described in Section 8.3.
8.1.5 The laboratory must, on an ongoing basis, demonstrate through
the analyses of quality control check standards that the operation of
the measurement system is in control. This procedure is described in
Section 8.4. The frequency of the check standard analyses is equivalent
to 10% of all samples analyzed but may be reduced if spike recoveries
from samples (Section 8.3) meet all specified quality control criteria.
8.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is described in
Section 8.5.
8.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
8.2.1 A quality control (QC) check sample concentrate is required
containing each parameter of interest at a concentration of 100 [mu]g/mL
in 2-propanol. The QC check sample concentrate must be obtained from the
U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory in Cincinnati, Ohio, if available. If not available
from that source, the QC check sample concentrate must be obtained from
another external source. If not available from either source above, the
QC check sample concentrate must be prepared by the laboratory using
stock standards prepared independently from those used for calibration.
8.2.2 Using a pipet, prepare QC check samples at a concentration of
100 [mu]g/L by adding 1.00 mL of QC check sample concentrate to each of
four 1-L aliquots of reagent water.
8.2.3 Analyze the well-mixed QC check samples according to the
method beginning in Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter
using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively, found in
Table 3. If s and X for all parameters of interest meet the acceptance
criteria, the system performance is acceptable and analysis of actual
samples can begin. If any individual s exceeds the precision limit or
any individual X falls outside the range for accuracy, the system
performance is unacceptable for that parameter.
Note: The large number of parameters in Talbe 3 present a
substantial probability that one or more will fail at least one of the
acceptance criteria when all parameters are analyzed.
8.2.6 When one or more of the parameters tested fail at least one of
the acceptance criteria, the analyst must proceed according to Section
8.2.6.1 or 8.2.6.2.
8.2.6.1 Locate and correct the source of the problem and repeat the
test for all parameters of interest beginning with Section 8.2.2.

[[Page 79]]

8.2.6.2 Beginning with Section 8.2.2, repeat the test only for those
parameters that failed to meet criteria. Repeated failure, however, will
confirm a general problem with the measurement system. If this occurs,
locate and correct the source of the problem and repeat the test for all
compounds of interest beginning with Section 8.2.2.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at 100 [mu]g/L or 1 to 5 times higher than the
background concentration determined in Section 8.3.2, whichever
concentration would be larger.
8.3.1.3 If it is impractical to determine background levels before
spiking (e.g., maximum holding times will be exceeded), the spike
concentration should be (1) the regulatory concentration limit, if any,
or, if none, (2) the larger of either 5 times higher than the expected
background concentration or 100 [mu]g/L.
8.3.2 Analyze one sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second sample aliquot with 1.0 mL
of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100(A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 3. These acceptance
criteria were calculated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.⁸ If spiking was performed at a concentration lower than
100 [mu]g/L, the analyst must use either the QC acceptance criteria in
Table 3, or optional QC acceptance criteria calculated for the specific
spike concentration. To calculate optional acceptance criteria for the
recovery of a parameter: (1) Calculate accuracy (X') using the equation
in Table 4, substituting the spike concentration (T) for C; (2)
calculate overall precision (S') using the equation in Table 4,
substituting X' for X; (3) calculate the range for recovery at the spike
concentration as (100 X'/T)+-2.44(100 S'/T)%.⁸
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory.
8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The
QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
3. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2sp to P+2sp.
If P=90% and sp=10%, for example, the accuracy interval is
expressed as 70-110%. Update the accuracy assessment for each parameter
on a regular basis (e.g. after each five to ten new accuracy
measurements).
8.6. It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates

[[Page 80]]

may be analyzed to assess the precision of the environmental
measurements. When doubt exists over the identification of a peak on the
chromatogram, confirmatory techniques such as gas chromatography with a
dissimilar column, specific element detector, or mass spectrometer must
be used. Whenever possible, the laboratory should analyze standard
reference materials and participate in relevant performance evaluation
studies.

9. Sample Collection, Preservation, and Handling

9.1 Grab samples must be collected in glass containers. Conventional
sampling practices ⁹ should be followed, except that the
bottle must not be prerinsed with sample before collection. Composite
samples should be collected in refrigerated glass containers in
accordance with the requirements of the program. Automatic sampling
equipment must be as free as possible of Tygon tubing and other
potential sources of contamination.
9.2 All samples must be iced or refrigerated at 4 [deg]C from the
time of collection until extraction. Fill the sample bottles and, if
residual chlorine is present, add 80 mg of sodium thiosulfate per liter
of sample and mix well. EPA Methods 330.4 and 330.5 may be used for
measurement of residual chlorine.¹⁰ Field test kits are
available for this purpose.
9.3 All samples must be extracted within 7 days of collection and
completely analyzed within 40 days of extraction.²

10. Sample Extraction

10.1 Mark the water meniscus on the side of sample bottle for later
determination of sample volume. Pour the entire sample into a 2-L
separatory funnel.
10.2 For samples high in organic content, the analyst may solvent
wash the sample at basic pH as prescribed in Sections 10.2.1 and 10.2.2
to remove potential method interferences. Prolonged or exhaustive
contact with solvent during the wash may result in low recovery of some
of the phenols, notably phenol and 2,4-dimethylphenol. For relatively
clean samples, the wash should be omitted and the extraction, beginning
with Section 10.3, should be followed.
10.2.1 Adjust the pH of the sample to 12.0 or greater with sodium
hydroxide solution.
10.2.2 Add 60 mL of methylene chloride to the sample by shaking the
funnel for 1 min with periodic venting to release excess pressure.
Discard the solvent layer. The wash can be repeated up to two additional
times if significant color is being removed.
10.3 Adjust the sample to a pH of 1 to 2 with sulfuric acid.
10.4 Add 60 mL of methylene chloride to the sample bottle, seal, and
shake 30 s to rinse the inner surface. Transfer the solvent to the
separatory funnel and extract the sample by shaking the funnel for 2
min. with periodic venting to release excess pressure. Allow the organic
layer to separate from the water phase for a minimum of 10 min. If the
emulsion interface between layers is more than one-third the volume of
the solvent layer, the analyst must employ mechanical techniques to
complete the phase separation. The optimum technique depends upon the
sample, but may include stirring, filtration of the emulsion through
glass wool, centrifugation, or other physical methods. Collect the
methylene chloride extract in a 250-mL Erlenmeyer flask.
10.5 Add a second 60-mL volume of methylene chloride to the sample
bottle and repeat the extraction procedure a second time, combining the
extracts in the Erlenmeyer flask. Perform a third extraction in the same
manner.
10.6 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-
mL concentrator tube to a 500-mL evaporative flask. Other concentration
devices or techniques may be used in place of the K-D concentrator if
the requirements of Section 8.2 are met.
10.7 Pour the combined extract through a solvent-rinsed drying
column containing about 10 cm of anhydrous sodium sulfate, and collect
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and
column with 20 to 30 mL of methylene chloride to complete the
quantitative transfer.
10.8 Add one or two clean boiling chips to the evaporative flask and
attach a three-ball Snyder column. Prewet the Snyder column by adding
about 1 mL of methylene chloride to the top. Place the K-D apparatus on
a hot water bath (60 to 65 [deg]C) so that the concentrator tube is
partially immersed in the hot water, and the entire lower rounded
surface of the flask is bathed with hot vapor. Adjust the vertical
position of the apparatus and the water temperature as required to
complete the concentration in 15 to 20 min. At the proper rate of
distillation the balls of the column will actively chatter but the
chambers will not flood with condensed solvent. When the apparent volume
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain
and cool for at least 10 min.
10.9 Increase the temperature of the hot water bath to 95 to 100
[deg]C. Remove the Synder column and rinse the flask and its lower joint
into the concentrator tube with 1 to 2 mL of 2-propanol. A 5-mL syringe
is recommended for this operation. Attach a two-ball micro-Snyder column
to the concentrator tube and prewet the column by adding about 0.5 mL of
2-propanol to the top. Place the micro-K-D apparatus on the water bath
so that the concentrator tube is partially immersed in the hot water.
Adjust the vertical position of the apparatus and the water temperature
as required to complete

[[Page 81]]

concentration in 5 to 10 min. At the proper rate of distillation the
balls of the column will actively chatter but the chambers will not
flood. When the apparent volume of liquid reaches 2.5 mL, remove the K-D
apparatus and allow it to drain and cool for at least 10 min. Add an
additional 2 mL of 2-propanol through the top of the micro-Snyder column
and resume concentrating as before. When the apparent volume of liquid
reaches 0.5 mL, remove the K-D apparatus and allow it to drain and cool
for at least 10 min.
10.10 Remove the micro-Snyder column and rinse its lower joint into
the concentrator tube with a minimum amount of 2-propanol. Adjust the
extract volume to 1.0 mL. Stopper the concentrator tube and store
refrigerated at 4 [deg]C if further processing will not be performed
immediately. If the extract will be stored longer than two days, it
should be transferred to a Teflon-sealed screw-cap vial. If the sample
extract requires no further cleanup, proceed with FIDGC analysis
(Section 11). If the sample requires further cleanup, proceed to Section
12.
10.11 Determine the original sample volume by refilling the sample
bottle to the mark and transferring the liquid to a 1000-mL graduated
cylinder. Record the sample volume to the nearest 5 mL.

11. Flame Ionization Detector Gas Chromatography

11.1 Table 1 summarizes the recommended operating conditions for the
gas chromatograph. Included in this table are retention times and MDL
that can be achieved under these conditions. An example of the
separations achieved by this column is shown in Figure 1. Other packed
or capillary (open-tubular) columns, chromatographic conditions, or
detectors may be used if the requirements of Section 8.2 are met.
11.2 Calibrate the system daily as described in Section 7.
11.3 If the internal standard calibration procedure is used, the
internal standard must be added to the sample extract and mixed
thoroughly immediately before injection into the gas chromatograph.
11.4 Inject 2 to 5 [mu]L of the sample extract or standard into the
gas chromatograph using the solvent-flush technique.¹¹
Smaller (1.0 [mu]L) volumes may be injected if automatic devices are
employed. Record the volume injected to the nearest 0.05 [mu]L, and the
resulting peak size in area or peak height units.
11.5 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
may be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.
11.6 If the response for a peak exceeds the working range of the
system, dilute the extract and reanalyze.
11.7 If the measurement of the peak response is prevented by the
presence of interferences, an alternative gas chromatographic procedure
is required. Section 12 describes a derivatization and column
chromatographic procedure which has been tested and found to be a
practical means of analyzing phenols in complex extracts.

12. Derivatization and Electron Capture Detector Gas Chromatography

12.1 Pipet a 1.0-mL aliquot of the 2-propanol solution of standard
or sample extract into a glass reaction vial. Add 1.0 mL of derivatizing
reagent (Section 6.11). This amount of reagent is sufficient to
derivatize a solution whose total phenolic content does not exceed 0.3
mg/mL.
12.2 Add about 3 mg of potassium carbonate to the solution and shake
gently.
12.3 Cap the mixture and heat it for 4 h at 80 [deg]C in a hot water
bath.
12.4 Remove the solution from the hot water bath and allow it to
cool.
12.5 Add 10 mL of hexane to the reaction flask and shake vigorously
for 1 min. Add 3.0 mL of distilled, deionized water to the reaction
flask and shake for 2 min. Decant a portion of the organic layer into a
concentrator tube and cap with a glass stopper.
12.6 Place 4.0 g of silica gel into a chromatographic column. Tap
the column to settle the silica gel and add about 2 g of anhydrous
sodium sulfate to the top.
12.7 Preelute the column with 6 mL of hexane. Discard the eluate and
just prior to exposure of the sodium sulfate layer to the air, pipet
onto the column 2.0 mL of the hexane solution (Section 12.5) that
contains the derivatized sample or standard. Elute the column with 10.0
mL of hexane and discard the eluate. Elute the column, in order, with:
10.0 mL of 15% toluene in hexane (Fraction 1); 10.0 mL of 40% toluene in
hexane (Fraction 2); 10.0 mL of 75% toluene in hexane (Fraction 3); and
10.0 mL of 15% 2-propanol in toluene (Fraction 4). All elution mixtures
are prepared on a volume: volume basis. Elution patterns for the
phenolic derivatives are shown in Table 2. Fractions may be combined as
desired, depending upon the specific phenols of interest or level of
interferences.
12.8 Analyze the fractions by ECDGC. Table 2 summarizes the
recommended operating conditions for the gas chromatograph. Included in
this table are retention times and MDL that can be achieved under these
conditions. An example of the separations

[[Page 82]]

achieved by this column is shown in Figure 2.
12.9 Calibrate the system daily with a minimum of three aliquots of
calibration standards, containing each of the phenols of interest that
are derivatized according to Section 7.5.
12.10 Inject 2 to 5 [mu]L of the column fractions into the gas
chromatograph using the solvent-flush technique. Smaller (1.0 [mu]L)
volumes can be injected if automatic devices are employed. Record the
volume injected to the nearest 0.05 [mu]L, and the resulting peak size
in area or peak height units. If the peak response exceeds the linear
range of the system, dilute the extract and reanalyze.

13. Calculations

13.1 Determine the concentration of individual compounds in the
sample analyzed by FIDGC (without derivatization) as indicated below.
13.1.1 If the external standard calibration procedure is used,
calculate the amount of material injected from the peak response using
the calibration curve or calibration factor determined in Section 7.2.2.
The concentration in the sample can be calculated from Equation 2.
[GRAPHIC] [TIFF OMITTED] TC15NO91.098

Equation 2

where:
A=Amount of material injected (ng).
Vi=Volume of extract injected ([mu]L).
Vt=Volume of total extract ([mu]L).
Vs=Volume of water extracted (mL).

13.1.2 If the internal standard calibration procedure is used,
calculate the concentration in the sample using the response factor (RF)
determined in Section 7.3.2 and Equation 3.
[GRAPHIC] [TIFF OMITTED] TC15NO91.099

Equation 3

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Is=Amount of internal standard added to each extract ([mu]g).
Vo=Volume of water extracted (L).

13.2 Determine the concentration of individual compounds in the
sample analyzed by derivatization and ECDGC according to Equation 4.
[GRAPHIC] [TIFF OMITTED] TC15NO91.100

Equation 4

where:
A=Mass of underivatized phenol represented by area of peak in sample
chromatogram, determined from calibration curve in Section 7.5.3 (ng).
Vi=Volume of eluate injected ([mu]L).
Vt=Total volume of column eluate or combined fractions from
which Vi was taken ([mu]L).
Vs=Volume of water extracted in Section 10.10 (mL).
B=Total volume of hexane added in Section 12.5 (mL).
C=Volume of hexane sample solution added to cleanup column in Section
12.7 (mL).
D=Total volume of 2-propanol extract prior to derivatization (mL).
E=Volume of 2-propanol extract carried through derivatization in Section
12.1 (mL).

13.3 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

14. Method Performance

14.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and reported with 99%
confidence that the value is above zero.¹ The MDL
concentrations listed in Tables 1 and 2 were obtained using reagent
water.¹² Similar results were achieved using representative
wastewaters. The MDL actually achieved in a given analysis will vary
depending on instrument sensitivity and matrix effects.
14.2 This method was tested by 20 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
as six concentrations over the range 12 to 450 [mu]g/L.\13\ Single
operator precision, overall precision, and method accuracy were found to
be directly related to the concentration of the parameter and
essentially independent of the sample matrix. Linear equations to
describe these relationships for a flame ionization detector are
presented in Table 4.

References

1. 40 CFR part 136, appendix B.
2. ``Determination of Phenols in Industrial and Municipal
Wastewaters,'' EPA 600/4-84-ABC, National Technical Information Service,
PBXYZ, Springfield, Virginia 22161, November 1984.
3. Kawahara, F. K. ``Microdetermination of Derivatives of Phenols
and Mercaptans by

[[Page 83]]

Means of Electron Capture Gas Chromatography,'' Analytical Chemistry,
40, 1009 (1968).
4. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard
Practices for Preparation of Sample Containers and for Preservation of
Organic Constituents,'' American Society for Testing and Materials,
Philadelphia.
5. ``Carcinogens--Working With Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
6. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
7. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
8. Provost, L. P., and Elder, R. S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3 is two times the value 1.22
derived in this report.)
9. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard
Practices for Sampling Water,'' American Society for Testing and
Materials, Philadelphia.
10. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methmds for
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S.
Environmental Protection Agency, Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio 45268, March 1979.
11. Burke, J. A. ``Gas Chromatography for Pesticide Residue
Analysis; Some Practical Aspects,'' Journal of the Association of
Official Analytical Chemists, 48, 1037 (1965).
12. ``Development of Detection Limits, EPA Method 604, Phenols,''
Special letter report for EPA Contract 68-03-2625, U.S. Environmental
Protection Agency, Environmental Monitoring and Support Laboratory,
Cincinnati, Ohio 45268.
13. ``EPA Method Study 14 Method 604-Phenols,'' EPA 600/4-84-044,
National Technical Information Service, PB84-196211, Springfield,
Virginia 22161, May 1984.

Table 1--Chromatographic Conditions and Method Detection Limits
------------------------------------------------------------------------
Method
Retention detection
Parameter time (min) limit ([mu]g/
L)
------------------------------------------------------------------------
2-Chlorophenol................................ 1.70 0.31
2-Nitrophenol................................. 2.00 0.45
Phenol........................................ 3.01 0.14
2,4-Dimethylphenol............................ 4.03 0.32
2,4-Dichlorophenol............................ 4.30 0.39
2,4,6-Trichlorophenol......................... 6.05 0.64
4-Chloro-3-methylphenol....................... 7.50 0.36
2,4-Dinitrophenol............................. 10.00 13.0
2-Methyl-4,6-dinitrophenol.................... 10.24 16.0
Pentachlorophenol............................. 12.42 7.4
4-Nitrophenol................................. 24.25 2.8
------------------------------------------------------------------------
Column conditions: Supelcoport (80/100 mesh) coated with 1% SP-1240DA
packed in a 1.8 m long x 2 mm ID glass column with nitrogen carrier
gas at 30 mL/min flow rate. Column temperature was 80 [deg]C at
injection, programmed immediately at 8 [deg]C/min to 150 [deg]C final
temperature. MDL were determined with an FID.

Table 2--Silica Gel Fractionation and Electron Capture Gas Chromatography of PFBB Derivatives
----------------------------------------------------------------------------------------------------------------
Percent recovery by Method
fraction a Retention detection
Parent compound ---------------------------- time limit
1 2 3 4 (min) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
2-Chlorophenol............................................... ..... 90 1 ..... 3.3 0.58
2-Nitrophenol................................................ ..... ..... 9 90 9.1 0.77
Phenol....................................................... ..... 90 10 ..... 1.8 2.2
2,4-Dimethylphenol........................................... ..... 95 7 ..... 2.9 0.63
2,4-Dichlorophenol........................................... ..... 95 1 ..... 5.8 0.68
2,4,6-Trichlorophenol........................................ 50 50 ..... ..... 7.0 0.58
4-Chloro-3-methylphenol...................................... ..... 84 14 ..... 4.8 1.8
Pentachlorophenol............................................ 75 20 ..... ..... 28.8 0.59
4-Nitrophenol................................................ ..... ..... 1 90 14.0 0.70
----------------------------------------------------------------------------------------------------------------
Column conditions: Chromosorb W-AW-DMCS (80/100 mesh) coated with 5% OV-17 packed in a 1.8 m long x 2.0 mm ID
glass column with 5% methane/95% argon carrier gas at 30 mL/min flow rate. Column temperature held isothermal
at 200 [deg]C. MDL were determined with an ECD.

a Eluant composition:
Fraction 1--15% toluene in hexane.
Fraction 2--40% toluene in hexane.
Fraction 3--75% toluene in hexane.
Fraction 4--15% 2-propanol in toluene.

[[Page 84]]

Table 3--QC Acceptance Criteria--Method 604
----------------------------------------------------------------------------------------------------------------
Test
conc. Limit for Range for X Range for
Parameter ([mu]g/ s ([mu]g/ ([mu]g/L) P, Ps
L) L) (percent)
----------------------------------------------------------------------------------------------------------------
4-Chloro-3-methylphenol........................................... 100 16.6 56.7-113.4 49-122
2-Chlorophenol.................................................... 100 27.0 54.1-110.2 38-126
2,4-Dichlorophenol................................................ 100 25.1 59.7-103.3 44-119
2,4-Dimethylphenol................................................ 100 33.3 50.4-100.0 24-118
4,6-Dinitro-2-methylphenol........................................ 100 25.0 42.4-123.6 30-136
2,4-Dinitrophenol................................................. 100 36.0 31.7-125.1 12-145
2-Nitrophenol..................................................... 100 22.5 56.6-103.8 43-117
4-Nitrophenol..................................................... 100 19.0 22.7-100.0 13-110
Pentachlorophenol................................................. 100 32.4 56.7-113.5 36-134
Phenol............................................................ 100 14.1 32.4-100.0 23-108
2,4,6-Trichlorophenol............................................. 100 16.6 60.8-110.4 53-119
----------------------------------------------------------------------------------------------------------------
s--Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X--Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps--Percent recovery measured (Section 8.3.2, Section 8.4.2).

Note: These criteria are based directly upon the method performance data in Table 4. Where necessary, the limits
for recovery have been broadened to assure applicability of the limits to concentrations below those used to
develop Table 4.

Table 4--Method Accuracy and Precision as Functions of Concentration--Method 604
----------------------------------------------------------------------------------------------------------------
Accuracy, as Single Analyst Overall
Parameter recovery, X' precision, sr' precision, S'
([mu]g/L) ([mu]g/L) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
4-Chloro-3-methylphenol................................ 0.87C-1.97 0.11X-0.21 0.16X+1.41
2-Chlorophenol......................................... 0.83C-0.84 0.18X+0.20 0.21X+0.75
2,4-Dichlorophenol..................................... 0.81C+0.48 0.17X-0.02 0.18X+0.62
2,4-Dimethylphenol..................................... 0.62C-1.64 0.30X-0.89 0.25X+0.48
4,6-Dinitro-2-methylphenol............................. 0.84C-1.01 0.15X+1.25 0.19X+5.85
2,4-Dinitrophenol...................................... 0.80C-1.58 0.27X-1.15 0.29X+4.51
2-Nitrophenol.......................................... 0.81C-0.76 0.15X+0.44 0.14X+3.84
4-Nitrophenol.......................................... 0.46C+0.18 0.17X+2.43 0.19X+4.79
Pentachlorophenol...................................... 0.83C+2.07 0.22X-0.58 0.23X+0.57
Phenol................................................. 0.43C+0.11 0.20X-0.88 0.17X+0.77
2,4,6-Trichlorophenol.................................. 0.86C-0.40 0.10X+0.53 0.13X+2.40
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
sr'=Expected single analyst standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
C=True value for the concentration, in [mu]g/L.
X=Average recovery found for measurements of samples containing a concentration of C, in [mu]g/L.

[[Page 85]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.012

[[Page 86]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.013

Method 605--Benzidines

1. Scope and Application

1.1 This method covers the determination of certain benzidines. The
following parameters can be determined by this method:

------------------------------------------------------------------------
Parameter Storet No CAS No.
------------------------------------------------------------------------
Benzidine..................................... 39120 92-87-5
3,3'-Dichlorobenzidine........................ 34631 91-94-1
------------------------------------------------------------------------

1.2 This is a high performance liquid chromatography (HPLC) method
applicable to the determination of the compounds listed above in
municipal and industrial discharges as provided under 40 CFR 136.1. When
this method is used to analyze unfamiliar samples for the compounds
above, identifications should be supported by at least one additional
qualitative technique. This method describes electrochemical conditions
at a second potential which can be used to confirm measurements made
with this method. Method 625 provides gas chromatograph/mass
spectrometer (GC/MS) conditions appropriate for the qualitative and
quantitative confirmation of results for the parameters listed above,
using the extract produced by this method.
1.3 The method detection limit (MDL, defined in Section 14.1)
¹ for each parameter is

[[Page 87]]

listed in Table 1. The MDL for a specific wastewater may differ from
those listed, depending upon the nature of the interferences in the
sample matrix.
1.4 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.5 This method is restricted to use by or under the supervision of
analysts experienced in the use of HPLC instrumentation and in the
interpretation of liquid chromatograms. Each analyst must demonstrate
the ability to generate acceptable results with this method using the
procedure described in Section 8.2.

2. Summary of Method

2.1 A measured volume of sample, approximately 1-L, is extracted
with chloroform using liquid-liquid extractions in a separatory funnel.
The chloroform extract is extracted with acid. The acid extract is then
neutralized and extracted with chloroform. The final chloroform extract
is exchanged to methanol while being concentrated using a rotary
evaporator. The extract is mixed with buffer and separated by HPLC. The
benzidine compounds are measured with an electrochemical
detector.²
2.2 The acid back-extraction acts as a general purpose cleanup to
aid in the elimination of interferences.

3. Interferences

3.1 Method interferences may be caused by contaminants in solvents,
reagents, glassware, and other sample processing hardware that lead to
discrete artifacts and/or elevated baselines in chromatograms. All of
these materials must be routinely demonstrated to be free from
interferences under the conditions of the analysis by running laboratory
reagent blanks as described in Section 8.1.3.
3.1.1 Glassware must be scrupulously cleaned.³ Clean all
glassware as soon as [chyph]possible after use by rinsing with the last
[chyph]solvent used in it. Solvent rinsing should [chyph]be followed by
detergent washing with hot [chyph]water, and rinses with tap water and
[chyph]distilled water. The glassware should then be [chyph]drained dry,
and heated in a muffle furnace at [chyph]400 [deg]C for 15 to 30 min.
Some thermally [chyph]stable materials may not be eliminated by
[chyph]this treatment. Solvent rinses with acetone [chyph]and pesticide
quality hexane may be substi[chyph]tuted for the muffle furnace heating.
Vol[chyph]umetric ware should not be heated in a muffle [chyph]furnace.
After drying and cooling, glass[chyph]ware should be sealed and stored
in a clean en[chyph]vironment to prevent any accumulation of [chyph]dust
or other contaminants. Store inverted or [chyph]capped with aluminum
foil.
3.1.2 The use of high purity reagents and solvents helps to minimize
interference problems. Purification of solvents by distillation in all-
glass systems may be required.
3.2 Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary
considerably from source to source, depending upon the nature and
diversity of the industrial complex or municipality [chyph]being
sampled. The cleanup procedures [chyph]that are inherent in the
extraction step are [chyph]used to overcome many of these
interfer[chyph]ences, but unique samples may require addi[chyph]tional
cleanup approaches to achieve [chyph]the MDL listed in Table 1.
3.3 Some dye plant effluents contain [chyph]large amounts of
components with re[chyph]tention times closed to benzidine. In
[chyph]these cases, it has been found useful to reduce the electrode
potential in order to eliminate interferences and still detect
benzidine. (See Section 12.7.)

4. Safety

4.1 The toxicity or carcinogenicity of each reagent used in this
method has not been precisely defined; however, each chemical compound
should be treated as a potential health harzard. From this viewpoint,
exposure to these chemicals must be reduced to the lowest possible level
by whatever means available. The laboratory is responsible for
maintaining a current awareness file of OSHA regulations regarding the
safe handling of the chemicals specified in this method. A reference
file of material data handling sheets should also be made available to
all personnel involved in the chemical analysis. Additional references
to laboratory safety are available and have been identified
^4-6 for the information of the analyst.
4.2 The following parameters covered by this method have been
tentatively classified as known or suspected, human or mammalian
carcinogens: benzidine and 3,3'-dichlorobenzidine. Primary standards of
these toxic compounds should be prepared in a hood. A NIOSH/MESA
approved toxic gas respirator should be worn when the analyst handles
high concentrations of these toxic compounds.
4.3 Exposure to chloroform should be minimized by performing all
extractions and extract concentrations in a hood or other well-
ventiliated area.

5. Apparatus and Materials

[[Page 88]]

chloride, and dried before use to minimize contamination.
5.1.2 Automatic sampler (optional)--The sampler must incorporate
glass sample containers for the collection of a minimum of 250 mL of
sample. Sample containers must be kept refrigerated at 4[deg]C and
protected from light during compositing. If the sampler uses a
peristaltic pump, a minimum length of compressible silicone rubber
tubing may be used. Before use, however, the compressible tubing should
be thoroughly rinsed with methanol, followed by repeated rinsings with
distilled water to minimize the potential for contamination of the
sample. An integrating flow meter is required to collect flow
proportional composites.
5.2 Glassware (All specifications are suggested):
5.2.1 Separatory funnels--2000, 1000, and 250-mL, with Teflon
stopcock.
5.2.2 Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
5.2.3 Rotary evaporator.
5.2.4 Flasks--Round bottom, 100-mL, with 24/40 joints.
5.2.5 Centrifuge tubes--Conical, graduated, with Teflon-lined screw
caps.
5.2.6 Pipettes--Pasteur, with bulbs.
5.3 Balance--Analytical, capable of accurately weighing 0.0001 g.
5.4 High performance liquid chromatograph (HPLC)--An analytical
system complete with column supplies, high pressure syringes, detector,
and compatible recorder. A data system is recommended for measuring peak
areas and retention times.
5.4.1 Solvent delivery system--With pulse damper, Altex 110A or
equivalent.
5.4.2 Injection valve (optional)--Waters U6K or equivalent.
5.4.3 Electrochemical detector--Bioanalyti[chyph]cal Systems LC-2A
with glassy carbon [chyph]electrode, or equivalent. This detector has
[chyph]proven effective in the analysis of wastewaters for the
parameters listed in the scope (Section 1.1), and was used to develop
the method performance statements in Section 14. Guidelines for the use
of alternate detectors are provided in Section 12.1.
5.4.4 Electrode polishing kit--Princeton Applied Research Model 9320
or equivalent.
5.4.5 Column--Lichrosorb RP-2, 5 micron particle diameter, in a 25
cm x 4.6 mm ID stainless steel column. This column was used to develop
the method performance statements in Section 14. Guidelines for the use
of alternate column packings are provided in Section 12.1.

6. Reagents

6.1 Reagent water--Reagent water is defined as a water in which an
interferent is not observed at the MDL of the parameters of interest.
6.2 Sodium hydroxide solution (5 N)--Dissolve 20 g of NaOH (ACS) in
reagent water and dilute to 100 mL.
6.3 Sodium hydroxide solution (1 M)--Dissolve 40 g of NaOH (ACS) in
reagent water and dilute to 1 L.
6.4 Sodium thiosulfate--(ACS) Granular.
6.5 Sodium tribasic phosphate (0.4 M)--Dissolve 160 g of trisodium
phosphate decahydrate (ACS) in reagent water and dilute to 1 L.
6.6 Sulfuric acid (1+1)--Slowly, add 50 mL of
H2SO4 (ACS, sp. gr. 1.84) to 50 mL of reagent
water.
6.7 Sulfuric acid (1 M)--Slowly, add 58 mL of
H2SO4 (ACS, sp. gr. 1.84) to reagent water and
dilute to 1 L.
6.8 Acetate buffer (0.1 M, pH 4.7)--Dissolve 5.8 mL of glacial
acetic acid (ACS) and 13.6 g of sodium acetate trihydrate (ACS) in
reagent water which has been purified by filtration through a RO-4
Millipore System or equivalent and dilute to 1 L.
6.9 Acetonitrile, chloroform (preserved with 1% ethanol), methanol--
Pesticide quality or equivalent.
6.10 Mobile phase--Place equal volumes of filtered acetonitrile
(Millipore type FH filter or equivalent) and filtered acetate buffer
(Millipore type GS filter or equivalent) in a narrow-mouth, glass
container and mix thoroughly. Prepare fresh weekly. Degas daily by
sonicating under vacuum, by heating an stirring, or by purging with
helium.
6.11 Stock standard solutions (1.00 [mu]g/[mu]L)--Stock standard
solutions may be prepared from pure standard materials or purchased as
certified solutions.
6.11.1 Prepare stock standard solutions by accurately weighing about
0.0100 g of pure material. Dissolve the material in methanol and dilute
to volume in a 10-mL volumetric flask. Larger volumes can be used at the
convenience of the analyst. When compound purity is assayed to be 96% or
greater, the weight can be used without correction to calculate the
concentration of the stock standard. Commercially prepared stock
standards can be used at any concentration if they are certified by the
manufacturer or by an independent source.
6.11.2 Transfer the stock standard solutions into Teflon-sealed
screw-cap bottles. Store at 4 [deg]C and protect from light. Stock
standard solutions should be checked frequently for signs of degradation
or evaporation, especially just prior to preparing calibration standards
from them.
6.11.3 Stock standard solutions must be replaced after six months,
or sooner if comparison with check standards indicates a problem.
6.12 Quality control check sample concentrate--See Section 8.2.1.

[[Page 89]]

7. Calibration

7.1 Establish chromatographic operating conditions equivalent to
those given in Table 1. The HPLC system can be calibrated using the
external standard technique (Section 7.2) or the internal standard
technique (Section 7.3).
7.2 External standard calibration procedure:
7.2.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask and diluting to volume
with mobile phase. One of the external standards should be at a
concentration near, but above, the MDL (Table 1) and the other
concentrations should correspond to the expected range of concentrations
found in real samples or should define the working range of the
detector.
7.2.2 Using syringe injections of 5 to 25 [mu]L or a constant volume
injection loop, analyze each calibration standard according to Section
12 and tabulate peak height or area responses against the mass injected.
The results can be used to prepare a calibration curve for each
compound. Alternatively, if the ratio of response to amount injected
(calibration factor) is a constant over the working range (<10% relative
standard deviation, RSD), linearity through the origin can be assumed
and the average ratio or calibration factor can be used in place of a
calibration curve.
7.3 Internal standard calibration procedure--To use this approach,
the analyst must select one or more internal standards that are similar
in analytical behavior to the compounds of interest. The analyst must
further demonstrate that the measurement of the internal standard is not
affected by method or matrix interferences. Because of these
limitations, no internal standard can be suggested that is applicable to
all samples.
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask. To each calibration
standard, add a known constant amount of one or more internal standards,
and dilute to volume with mobile phase. One of the standards should be
at a concentration near, but above, the MDL and the other concentrations
should correspond to the expected range of concentrations found in real
samples or should define the working range of the detector.
7.3.2 Using syringe injections of 5 to 25 [mu]L or a constant volume
injection loop, analyze each calibration standard according to Section
12 and tabulate peak height or area responses against concentration for
each compound and internal standard. Calculate response factors (RF) for
each compound using Equation 1.

RF= (As)(Cis) (Ais)(Cs)
----------------------------------------------------------------------------------------------------------------

Equation 1

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Cis=Concentration of the internal standard ([mu]g/L).
Cs=Concentration of the parameter to be measured ([mu]g/L).

8. Quality Control

[[Page 90]]

the method, the analyst is required to repeat the procedure in Section
8.2.
8.1.3 Before processing any samples, the analyst must analyze a
reagent water blank to demonstrate that interferences from the
analytical system and glassware are under control. Each time a set of
samples is extracted or reagents are changed, a reagent water blank must
be processed as a safeguard against laboratory contamination.
8.1.4 The laboratory must, on an ongoing basis, spike and analyze a
minimum of 10% of all samples to monitor and evaluate laboratory data
quality. This procedure is described in Section 8.3.
8.1.5 The laboratory must, on an ongoing basis, demonstrate through
the analyses of quality control check standards that the operation of
the measurement system is in control. This procedure is described in
Section 8.4. The frequency of the check standard analyses is equivalent
to 10% of all samples analyzed but may be reduced if spike recoveries
from samples (Section 8.3) meet all specified quality control criteria.
8.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is described in
Section 8.5.
8.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
8.2.1 A quality control (QC) check sample concentrate is required
containing benzidine and/or 3,3'-dichlorobenzidine at a concentration of
50 [mu]g/mL each in methanol. The QC check sample concentrate must be
obtained from the U.S. Environmental Protection Agency, Environmental
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If
not available from that source, the QC check sample concentrate must be
obtained from another external source. If not available from either
source above, the QC check sample concentrate must be prepared by the
laboratory using stock standards prepared independently from those used
for calibration.
8.2.2 Using a pipet, prepare QC check samples at a concentration of
50 [mu]g/L by adding 1.00 mL of QC check sample concentrate to each of
four 1-L-L aliquots of reagent water.
8.2.3 Analyze the well-mixed QC check samples according to the
method beginning in Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter
using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively, found in
Table 2. If s and X for all parameters of interest meet the acceptance
criteria, the system performance is acceptable and analysis of actual
samples can begin. If any individual s exceeds the precision limit or
any individual X falls outside the range for accuracy, the system
performance is unacceptable for that parameter. Locate and correct the
source of the problem and repeat the test for all parameters of interest
beginning with Section 8.2.2.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at 50 [mu]g/L or 1 to 5 times higher than the background
concentration determined in Section 8.3.2, whichever concentration would
be larger.
8.3.1.3 If it is impractical to determine background levels before
spiking (e.g., maximum holding times will be exceeded), the spike
concentration should be (1) the regulatory concentration limit, if any;
or, if none (2) the larger of either 5 times higher than the expected
background concentration or 50 [mu]g/L.
8.3.2 Analyze one sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second sample aliquot with 1.0 mL
of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100(A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 2. These acceptance
criteria were calculated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.\7\ If spiking was performed at a concentration lower than 50 [mu]g/
L, the analyst must use either the QC acceptance criteria in Table 2, or
optional QC acceptance criteria calculated for the specific spike
concentration. To calculate optional acceptance criteria for the
recovery of a parameter: (1) Calculate accuracy (X') using the equation
in Table 3, substituting

[[Page 91]]

the spike concentration (T) for C; (2) calculate overall precision (S')
using the equation in Table 3, substituting X' for X; (3) calculate the
range for recovery at the spike concentration as (100 X'/T)+-2.44(100
S'/T)%.\7\
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory.
8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check
sample concentrate (Sections 8.2.1 or 8.3.2) to 1 L of reagent water.
The QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
2. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2sp to P+2sp.
If P=90% and sp=10%, for example, the accuracy interval is
expressed as 70-110%. Update the accuracy assessment for each parameter
on a regular basis (e.g. after each five to ten new accuracy
measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates may be analyzed to assess the
precision of the environmental measurements. When doubt exists over the
identification of a peak on the chromatogram, confirmatory techniques
such as HPLC with a dissimilar column, gas chromatography, or mass
spectrometer must be used. Whenever possible, the laboratory should
analyze standard reference materials and participate in relevant
performance evaluation studies.

9. Sample Collection, Preservation, and Handling

9.1 Grab samples must be collected in glass containers. Conventional
sampling practices\8\ should be followed, except that the bottle must
not be prerinsed with sample before collection. Composite samples should
be collected in refrigerated glass containers in accordance with the
requirements of the program. Automatic sampling equipment must be as
free as possible of Tygon tubing and other potential sources of
contamination.
9.2 All samples must be iced or refrigerated at 4[deg]C and stored
in the dark from the time of collection until extraction. Both benzidine
and 3,3'-dichlorobenzidine are easily oxidized. Fill the sample bottles
and, if residual chlorine is present, add 80 mg of sodium thiosulfate
per liter of sample and mix well. EPA Methods 330.4 and 330.5 may be
used for measurement of residual chlorine.\9\ Field test kits are
available for this purpose. After mixing, adjust the pH of the sample to
a range of 2 to 7 with sulfuric acid.
9.3 If 1,2-diphenylhydrazine is likely to be present, adjust the pH
of the sample to 4.0+- 0.2 to prevent rearrangement to benzidine.
9.4 All samples must be extracted within 7 days of collection.
Extracts may be held up to 7 days before analysis, if stored under an
inert (oxidant free) atmosphere.\2\ The extract should be protected from
light.

10. Sample Extraction

[[Page 92]]

wool, centrifugation, or other physical methods. Collect the chloroform
extract in a 250-mL separatory funnel.
10.3 Add a 50-mL volume of chloroform to the sample bottle and
repeat the extraction procedure a second time, combining the extracts in
the separatory funnel. Perform a third extraction in the same manner.
10.4 Separate and discard any aqueous layer remaining in the 250-mL
separatory funnel after combining the organic extracts. Add 25 mL of 1 M
sulfuric acid and extract the sample by shaking the funnel for 2 min.
Transfer the aqueous layer to a 250-mL beaker. Extract with two
additional 25-mL portions of 1 M sulfuric acid and combine the acid
extracts in the beaker.
10.5 Place a stirbar in the 250-mL beaker and stir the acid extract
while carefully adding 5 mL of 0.4 M sodium tribasic phosphate. While
monitoring with a pH meter, neutralize the extract to a pH between 6 and
7 by dropwise addition of 5 N sodium hydroxide solution while stirring
the solution vigorously. Approximately 25 to 30 mL of 5 N sodium
hydroxide solution will be required and it should be added over at least
a 2-min period. Do not allow the sample pH to exceed 8.
10.6 Transfer the neutralized extract into a 250-mL separatory
funnel. Add 30 mL of chloroform and shake the funnel for 2 min. Allow
the phases to separate, and transfer the organic layer to a second 250-
mL separatory funnel.
10.7 Extract the aqueous layer with two additional 20-mL aliquots of
chloroform as before. Combine the extracts in the 250-mL separatory
funnel.
10.8 Add 20 mL of reagent water to the combined organic layers and
shake for 30 s.
10.9 Transfer the organic extract into a 100-mL round bottom flask.
Add 20 mL of methanol and concentrate to 5 mL with a rotary evaporator
at reduced pressure and 35 [deg]C. An aspirator is recommended for use
as the source of vacuum. Chill the receiver with ice. This operation
requires approximately 10 min. Other concentration techniques may be
used if the requirements of Section 8.2 are met.
10.10 Using a 9-in. Pasteur pipette, transfer the extract to a 15-
mL, conical, screw-cap centrifuge tube. Rinse the flask, including the
entire side wall, with 2-mL portions of methanol and combine with the
original extract.
10.11 Carefully concentrate the extract to 0.5 mL using a gentle
stream of nitrogen while heating in a 30 [deg]C water bath. Dilute to 2
mL with methanol, reconcentrate to 1 mL, and dilute to 5 mL with acetate
buffer. Mix the extract thoroughly. Cap the centrifuge tube and store
refrigerated and protected from light if further processing will not be
performed immediately. If the extract will be stored longer than two
days, it should be transferred to a Teflon-sealed screw-cap vial. If the
sample extract requires no further cleanup, proceed with HPLC analysis
(Section 12). If the sample requires further cleanup, proceed to Section
11.
10.12 Determine the original sample volume by refilling the sample
bottle to the mark and transferring the liquid to a 1,000-mL graduated
cylinder. Record the sample volume to the nearest 5 mL.

11. Cleanup and Separation

11.1 Cleanup procedures may not be necessary for a relatively clean
sample matrix. If particular circumstances demand the use of a cleanup
procedure, the analyst first must demonstrate that the requirements of
Section 8.2 can be met using the method as revised to incorporate the
cleanup procedure.

12. High Performance Liquid Chromatography

12.1 Table 1 summarizes the recommended operating conditions for the
HPLC. Included in this table are retention times, capacity factors, and
MDL that can be achieved under these conditions. An example of the
separations achieved by this HPLC column is shown in Figure 1. Other
HPLC columns, chromatographic conditions, or detectors may be used if
the requirements of Section 8.2 are met. When the HPLC is idle, it is
advisable to maintain a 0.1 mL/min flow through the column to prolong
column life.
12.2 Calibrate the system daily as described in Section 7.
12.3 If the internal standard calibration procedure is being used,
the internal standard must be added to the sample extract and mixed
thoroughly immediately before injection into the instrument.
12.4 Inject 5 to 25 [mu]L of the sample extract or standard into the
HPLC. If constant volume injection loops are not used, record the volume
injected to the nearest 0.05 [mu]L, and the resulting peak size in area
or peak height units.
12.5 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
can be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.
12.6 If the response for a peak exceeds the working range of the
system, dilute the extract with mobile phase and reanalyze.
12.7 If the measurement of the peak response for benzidine is
prevented by the presence of interferences, reduce the electrode

[[Page 93]]

potential to +0.6 V and reanalyze. If the benzidine peak is still
obscured by interferences, further cleanup is required.

13. Calculations

13.1 Determine the concentration of individual compounds in the
sample.
13.1.1 If the external standard calibration procedure is used,
calculate the amount of material injected from the peak response using
the calibration curve or calibration factor determined in Section 7.2.2.
The concentration in the sample can be calculated from Equation 2.
[GRAPHIC] [TIFF OMITTED] TC15NO91.101

Equation 2

where:
A=Amount of material injected (ng).
Vi=Volume of extract injected ([mu]L).
Vt=Volume of total extract ([mu]L).
Vs=Volume of water extracted (mL).

Equation 3

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Is=Amount of internal standard added to each extract ([mu]g).
Vo=Volume of water extracted (L).

13.2 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

14. Method Performance

14.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and reported with 99%
confidence that the value is above zero.\1\ The MDL concentrations
listed in Table 1 were obtained using reagent water.\10\ Similar results
were achieved using representative wastewaters. The MDL actually
achieved in a given analysis will vary depending on instrument
sensitivity and matrix effects.
14.2 This method has been tested for linearity of spike recovery
from reagent water and has been demonstrated to be applicable over the
concentration range from 7xMDL to 3000xMDL.\10\
14.3 This method was tested by 17 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
at six concentrations over the range 1.0 to 70 [mu]g/L.\11\ Single
operator precision, overall precision, and method accuracy were found to
be directly related to the concentration of the parameter and
essentially independent of the sample matrix. Linear equations to
describe these relationships are presented in Table 3.

References

1. 40 CFR part 136, appendix B.
2. ``Determination of Benzidines in Industrial and Muncipal
Wastewaters,'' EPA 600/4-82-022, National Technical Information Service,
PB82-196320, Springfield, Virginia 22161, April 1982.
3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard
Practices for Preparation of Sample Containers and for Preservation of
Organic Constituents,'' American Society for Testing and Materials,
Philadelphia.
4. ``Carcinogens--Working With Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
6. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3 is two times the value 1.22
derived in this report.)
8. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard
Practices for Sampling Water,'' American Society for Testing and
Materials, Philadelphia.
9. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5
(Spectrophotometric, DPD) for Chlorine Total Residual,'' Methods for
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S.
Environmental Protection Agency, Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio 45268, March 1979.
10. ``EPA Method Study 15, Method 605 (Benzidines),'' EPA 600/4-84-
062, National Technical Information Service, PB84-211176, Springfield,
Virginia 22161, June 1984.
11. ``EPA Method Validation Study 15, Method 605 (Benzidines),''
Report for EPA Contract 68-03-2624 (In preparation).

[[Page 94]]

Table 1--Chromatographic Conditions and Method Detection Limits
------------------------------------------------------------------------
Method
Retention Column detection
Parameter time (min) capacity limit
factor (k') ([mu]g/L)
------------------------------------------------------------------------
Benzidine........................ 6.1 1.44 0.08
3,3'-Dichlorobenzidine........... 12.1 3.84 0.13
------------------------------------------------------------------------
HPLC Column conditions: Lichrosorb RP-2, 5 micron particle size, in a 25
cmx4.6 mm ID stainless steel column. Mobile Phase: 0.8 mL/min of 50%
acetonitrile/50% 0.1M pH 4.7 acetate buffer. The MDL were determined
using an electrochemical detector operated at +0.8 V.

Table 2--QC Acceptance Criteria--Method 605
----------------------------------------------------------------------------------------------------------------
Test Limit for Range for Range for
Parameter conc. s ([mu]g/ X ([mu]g/ P, Ps
([mu]g/L) L) L) (percent)
----------------------------------------------------------------------------------------------------------------
Benzidine.......................................................... 50 18.7 9.1-61.0 D-140
3.3'-Dichlorobenzidine............................................. 50 23.6 18.7-50.0 5-128
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).
D=Detected; result must be greater than zero.

Table 3--Method Accuracy and Precision as Functions of Concentration--Method 605
----------------------------------------------------------------------------------------------------------------
Accuracy, as Single analyst Overall
Parameter recovery, precision, sr' precision, S'
X'([mu]g/L) ([mu]g/L) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
Benzidine....................................................... 0.70C+0.06 0.28X+0.19 0.40X+0.18
3,3'-Dichlorobenzidine.......................................... 0.66C+0.23 0.39X-0.05 0.38X+0.02
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
sr'=Expected single analyst standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
C=True value for the concentration, in [mu]g/L.
X=Average recovery found for measurements of samples containing a concentration of C, in [mu]g/L.

[[Page 95]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.014

[[Page 96]]

Method 606--Phthalate Ester

1. Scope and Application

1.1 This method covers the determination of certain phthalate
esters. The following parameters can be determined by this method:

1.2 This is a gas chromatographic (GC) method applicable to the
determination of the compounds listed above in municipal and industrial
discharges as provided under 40 CFR 136.1. When this method is used to
analyze unfamiliar samples for any or all of the compounds above,
compound identifications should be supported by at least one additional
qualitative technique. This method describes analytical conditions for a
second gas chromatographic column that can be used to confirm
measurements made with the primary column. Method 625 provides gas
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the
qualitative and quantitative confirmation of results for all of the
parameters listed above, using the extract produced by this method.
1.3 The method detection limit (MDL, defined in Section 14.1)\1\ for
each parameter is listed in Table 1. The MDL for a specific wastewater
may differ from those listed, depending upon the nature of interferences
in the sample matrix.
1.4 The sample extraction and concentration steps in this method are
essentially the same as in Methods 608, 609, 611, and 612. Thus, a
single sample may be extracted to measure the parameters included in the
scope of each of these methods. When cleanup is required, the
concentration levels must be high enough to permit selecting aliquots,
as necessary, to apply appropriate cleanup procedures. The analyst is
allowed the latitude, under Section 12, to select chromatographic
conditions appropriate for the simultaneous measurement of combinations
of these parameters.
1.5 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.6 This method is restricted to use by or under the supervision of
analysts experienced in the use of a gas chromatograph and in the
interpretation of gas chromatograms. Each analyst must demonstrate the
ability to generate acceptable results with this method using the
procedure described in Section 8.2.

2. Summary of Method

2.1 A measured volume of sample, approximately 1-L, is extracted
with methylene chloride using a separatory funnel. The methylene
chloride extract is dried and exchanged to hexane during concentration
to a volume of 10 mL or less. The extract is separated by gas
chromatography and the phthalate esters are then measured with an
electron capture detector.\2\
2.2 Analysis for phthalates is especially complicated by their
ubiquitous occurrence in the environment. The method provides Florisil
and alumina column cleanup procedures to aid in the elimination of
interferences that may be encountered.

3. Interferences

3.1 Method interferences may be caused by contaminants in solvents,
reagents, glassware, and other sample processing hardware that lead to
discrete artifacts and/or elevated baselines in gas chromatograms. All
of these materials must be routinely demonstrated to be free from
interferences under the conditions of the analysis by running laboratory
reagent blanks as described in Section 8.1.3.
3.1.1 Glassware must be scrupulously cleaned.\3\ Clean all glassware
[chyph]as soon as possible after use by rinsing with the last solvent
used in it. Solvent rinsing should be followed by detergent washing with
hot water, and rinses with tap water and distilled water. The glassware
should then be drained dry, and heated in a muffle furnace at 400 [deg]C
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not
be eliminated by this treatment. Solvent rinses with acetone and
pesticide quality hexane may be substituted for the muffle furnace
heating. Thorough rinsing with such solvents usually eliminates PCB
interference. Volumetric ware should not be heated in a muffle furnace.
After drying and cooling, glassware should be sealed and stored in a
clean environment to prevent any accumulation of dust or other
contaminants. Store inverted or capped with aluminum foil.
3.1.2 The use of high purity reagents and solvents helps to minimize
interference problems. Purification of solvents by distillation in all-
glass systems may be required.
3.2 Phthalate esters are contaminants in many products commonly
found in the laboratory. It is particularly important to avoid the use
of plastics because phthalates are commonly used as plasticizers and are
easily extracted from plastic materials. Serious phthalate contamination
can result at any time, if consistent quality control is not practiced.
Great care must be experienced to prevent such contamination. Exhaustive
cleanup of reagents and glassware may be required to eliminate
background phthalate contamination.^4,5

[[Page 97]]

3.3 Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary
considerably from source to source, depending upon the nature and
diversity of the industrial complex or municipality being sampled. The
cleanup procedures in Section 11 can be used to overcome many of these
interferences, but unique samples may require additional cleanup
approaches to achieve the MDL listed in Table 1.

4. Safety

5. Apparatus and Materials

5.1 Sampling equipment, for discrete or composite sampling.
5.1.1 Grab sample bottle--1-L or 1-qt, amber glass, fitted with a
screw cap lined with Teflon. Foil may be substituted for Teflon if the
sample is not corrosive. If amber bottles are not available, protect
samples from light. The bottle and cap liner must be washed, rinsed with
acetone or methylene chloride, and dried before use to minimize
contamination.
5.1.2 Automatic sampler (optional)--The sampler must incorporate
glass sample containers for the collection of a minimum of 250 mL of
sample. Sample containers must be kept refrigerated at 4 [deg]C and
protected from light during compositing. If the sampler uses a
peristaltic pump, a minimum length of compressible silicone rubber
tubing may be used. Before use, however, the compressible tubing should
be thoroughly rinsed with methanol, followed by repeated rinsings with
distilled water to minimize the potential for contamination of the
sample. An integrating flow meter is required to collect flow
proportional composites.
5.2 Glassware (All specifications are suggested. Catalog numbers are
included for illustration only).
5.2.1 Separatory funnel--2-L, with Teflon stopcock.
5.2.2 Drying column--Chromatographic column, approximately 400 mm
long x 19 mm ID, with coarse frit filter disc.
5.2.3 Chromatographic column--300 mm long x 10 mm ID, with Teflon
stopcock and coarse frit filter disc at bottom (Kontes K-420540-0213 or
equivalent).
5.2.4 Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes K-
570050-1025 or equivalent). Calibration must be checked at the volumes
employed in the test. Ground glass stopper is used to prevent
evaporation of extracts.
5.2.5 Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
5.2.6 Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
5.2.7 Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
5.2.8 Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
5.3 Boiling chips--Approximately 10/40 mesh. Heat to 400 [deg]C for
30 min or Soxhlet extract with methylene chloride.
5.4 Water bath--Heated, with concentric ring cover, capable of
temperature control (+-2 [deg]C). The bath should be used in a hood.
5.5 Balance--Analytical, capable of accurately weighing 0.0001 g.
5.6 Gas chromatograph--An analytical system complete with gas
chromatograph suitable for on-column injection and all required
accessories including syringes, analytical columns, gases, detector, and
strip-chart recorder. A data system is recommended for measuring peak
areas.
5.6.1 Column 1--1.8 m long x 4 mm ID glass, packed with 1.5% SP-
2250/1.95% SP-2401 Supelcoport (100/120 mesh) or equivalent. This column
was used to develop the method performance statemelts in Section 14.
Guidelines for the use of alternate column packings are provided in
Section 12.1.
5.6.2 Column 2--1.8 m long x 4 mm ID glass, packed with 3% OV-1 on
Supelcoport (100/120 mesh) or equivalent.
5.6.3 Detector--Electron capture detector. This detector has proven
effective in the analysis of wastewaters for the parameters listed in
the scope (Section 1.1), and was used to develop the method performance
statements in Section 14. Guidelines for the use of alternate detectors
are provided in Section 12.1.

6. Reagents

6.1 Reagent water--Reagent water is defined as a water in which an
interferent is not observed at the MDL of the parameters of interest.
6.2 Acetone, hexane, isooctane, methylene chloride, methanol--
Pesticide quality or equivalent.
6.3 Ethyl ether--nanograde, redistilled in glass if necessary.
6.3.1 Ethyl ether must be shown to be free of peroxides before it is
used as indicated by

[[Page 98]]

EM Laboratories Quant test strips. (Available from Scientific Products
Co., Cat. No. P1126-8, and other suppliers.)
6.3.2 Procedures recommended for removal of peroxides are provided
with the test strips. After cleanup, 20 mL of ethyl alcohol preservative
must be added to each liter of ether.
6.4 Sodium sulfate--(ACS) Granular, anhydrous. Several levels of
purification may be required in order to reduce background phthalate
levels to an acceptable level: 1) Heat 4 h at 400 [deg]C in a shallow
tray, 2) Heat 16 h at 450 to 500 [deg]C in a shallow tray, 3) Soxhlet
extract with methylene chloride for 48 h.
6.5 Florisil--PR grade (60/100 mesh). Purchase activated at 1250
[deg]F and store in the dark in glass containers with ground glass
stoppers or foil-lined screw caps. To prepare for use, place 100 g of
Florisil into a 500-mL beaker and heat for approximately 16 h at 40
[deg]C. After heating transfer to a 500-mL reagent bottle. Tightly seal
and cool to room temperature. When cool add 3 mL of reagent water. Mix
thoroughly by shaking or rolling for 10 min and let it stand for at
least 2 h. Keep the bottle sealed tightly.
6.6 Alumina--Neutral activity Super I, W200 series (ICN Life
Sciences Group, No. 404583). To prepare for use, place 100 g of alumina
into a 500-mL beaker and heat for approximately 16 h at 400 [deg]C.
After heating transfer to a 500-mL reagent bottle. Tightly seal and cool
to room temperature. When cool add 3 mL of reagent water. Mix thoroughly
by shaking or rolling for 10 min and let it stand for at least 2 h. Keep
the bottle sealed tightly.
6.7 Stock standard solutions (1.00 [mu]g/[mu]L)--Stock standard
solutions can be prepared from pure standard materials or purchased as
certified solutions.
6.7.1 Prepare stock standard solutions by accurately weighing about
0.0100 g of pure material. Dissolve the material in isooctane and dilute
to volume in a 10-mL volumetric flask. Larger volumes can be used at the
convenience of the analyst. When compound purity is assayed to be 96% or
greater, the weight can be used without correction to calculate the
concentration of the stock standard. Commercially prepared stock
standards can be used at any concentration if they are certified by the
manufacturer or by an independent source.
6.7.2 Transfer the stock standard solutions into Teflon-sealed
screw-cap bottles. Store at 4 [deg]C and protect from light. Stock
standard solutions should be checked frequently for signs of degradation
or evaporation, especially just prior to preparing calibration standards
from them.
6.7.3 Stock standard solutions must be replaced after six months, or
sooner if comparison with check standards indicates a problem.
6.8 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

7.1 Establish gas chromatograph operating conditions equivalent to
those given in Table 1. The gas chromatographic system can be calibrated
using the external standard technique (Section 7.2) or the internal
standard technique (Section 7.3).
7.2 External standard calibration procedure:
7.2.1 Prepared calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask and diluting to volume
with isooctane. One of the external standards should be at a
concentration near, but above, the MDL (Table 1) and the other
concentrations should correspond to the expected range of concentrations
found in real samples or should define the working range of the
detector.
7.2.2 Using injections of 2 to 5 [mu]L, analyze each calibration
standard according to Section 12 and tabulate peak height or area
responses against the mass injected. The results can be used to prepare
a calibration curve for each compound. Alternatively, if the ratio of
response to amount injected (calibration factor) is a constant over the
working range (<10% relative standard deviation, RSD), linearity through
the origin can be assumed and the average ratio or calibration factor
can be used in place of a calibration curve.
7.3 Internal standard calibration procedure--To use this approach,
the analyst must select one or more internal standards that are similar
in analytical behavior to the compounds of interest. The analyst must
further demonstrate that the measurement of the internal standard is not
affected by method or matrix interferences. Because of these
limitations, no internal standard can be suggested that is applicable to
all samples.
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flash. To each calibration
standard, add a known constant amount of one or more internal standards,
and dilute to volume with isooctane. One of the standards should be at a
concentraton near, but above, the MDL and the other concentrations
should correspond to the expected range of concentrations found in real
samples or should define the working range of the detector.

[[Page 99]]

7.3.2 Using injections of 2 to 5 [mu]L, analyze each calibration
standard according to Section 12 and tabulate peak height or area
responses against concentration for each compound and internal standard.
Calculate response factors (RF) for each compound using Equation 1.

RF= (As)(Cis) (Ais)(Cs)
----------------------------------------------------------------------------------------------------------------

Equation 1

8. Quality Control

8.1 Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements of this program
consist of an initial demonstration of laboratory capability and an
ongoing analysis of spiked samples to evaluate and document data
quality. The laboratory must maintain records to document the quality of
data that is generated. Ongoing data quality checks are compared with
established performance criteria to determine if the results of analyses
meet the performance characteristics of the method. When results of
sample spikes indicate atypical method performance, a quality control
check standard must be analyzed to confirm that the measurements were
performed in an in-control mode of operation.
8.1.1 The analyst must make an initial, one-time, demonstration of
the ability to generate acceptable accuracy and precision with this
method. This ability is established as described in Section 8.2.
8.1.2 In recognition of advances that are occurring in
chromatography, the analyst is permitted certain options (detailed in
Sections 10.4, 11.1, and 12.1) to improve the separations or lower the
cost of measurements. Each time such a modification is made to the
method, the analyst is required to repeat the procedure in Section 8.2.
8.1.3 Before processing any samples, the analyst must analyze a
reagent water blank to demonstrate that interferences from the
analytical system and glassware are under control. Each time a set of
samples is extracted or reagents are changed, a reagent water blank must
be processed as a safeguard against laboratory contamination.
8.1.4 The laboratory must, on an ongoing basis, spike and analyze a
minimum of 10% of all samples to monitor and evaluate laboratory data
quality. This procedure is described in Section 8.3.
8.1.5 The laboratory must, on an ongoing basis, demonstrate through
the analyses of quality control check standards that the operation of
the measurement system is in control. This procedure is described in
Section 8.4. The frequency of the check standard analyses is equivalent
to 10% of all samples analyzed but may be reduced if spike recoveries
from samples (Section 8.3) meet all specified quality control criteria.
8.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is described in
Section 8.5.
8.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
8.2.1 A quality contrml (QC) check sample concentrate is required
containing each parameter of interest at the following concentrations in
acetone: butyl benzyl phthalate, 10 [mu]g/mL; bis(2-ethylhexyl)
phthalate, 50 [mu]g/mL; di-n-octyl phthalate, 50 [mu]g/mL; any other
phthlate, 25 [mu]g/mL. The QC check sample concentrate must be obtained
from the U.S. Environmental Protection Agancy, Environmental Monitoring
and Support Laboratory in Cincinnati, Ohio, if available. If not
available from that source, the QC check sample concentrate must be
obtained from another external source. If not available from either
source above, the QC check sample concentrate must be prepared by the
laboratory using stock standards prepared independently from those used
for calibration.
8.2.2 Using a pipet, prepare QC check samples at the test
concentrations shown in Table 2 by adding 1.00 mL of QC check sample
concentrate to each of four 1-L aliquots of reagent water.
8.2.3 Analyze the well-mixed QC check samples according to the
method beginning in Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter
using the four results.

[[Page 100]]

8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively, found in
Table 2. If s and X for all parameters of interest meet the acceptance
criteria, the system performance is acceptable and analysis of actual
samples can begin. If any individual s exceeds the precision limit or
any individual X falls outside the range for accuracy, the system
performance is unacceptable for that parameter. Locate and correct the
source of the problem and repeat the test for all parameters of interest
beginning with Section 8.2.2.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at the test concentration in Section 8.2.2 or 1 to 5
times higher than the background concentration determined in Section
8.3.2, whichever concentration would be larger.
8.3.1.3 If it is impractical to determine background levels before
spiking (e.g., maximum holding times will be exceeded), the spike
concentration should be (1) the regulatory concentration limit, if any;
or, if none (2) the larger of either 5 times higher than the expected
background concentration or the test concentration in Section 8.2.2.
8.3.2 Analyze one sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second sample aliquot with 1.0 mL
of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100(A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 2. These acceptance
criteria were calculated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.\9\ If spiking was performed at a concentration lower than the test
concentration in Section 8.2.2, the analyst must use either the QC
acceptance criteria in Table 2, or optional QC acceptance criteria
calculated for the specific spike concentration. To calculate optional
acceptance criteria for the recovery of a parameter: (1) Calculate
accuracy (X') using the equation in Table 3, substituting the spike
concentration (T) for C; (2) calculate overall precision (S') using the
equation in Table 3, substituting X' for X; (3) calculate the range for
recovery at the spike concentration as (100 X'/T)+-2.44(100 S'/T)%.\9\
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory.
8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The
QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
2. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2sp to P+2sp.
If P=90% and sp=10%, for example, the accuracy interval is
expressed as 70-110%.

[[Page 101]]

Update the accuracy assessment for each parameter on a regular basis
(e.g. after each five to ten new accuracy measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates may be analyzed to assess the
precision of the environmental measurements. When doubt exists over the
identification of a peak on the chromatogram, confirmatory techniques
such as gas chromatography with a dissimilar column, specific element
detector, or mass spectrometer must be used. Whenever possible, the
laboratory should analyze standard reference materials and participate
in relevant performance evaluation studies.

9. Sample Collection, Preservation, and Handling

9.1 Grab samples must be collected in glass containers. Conventional
sampling practices\10\ should be followed, except that the bottle must
not be prerinsed with sample before collection. Composite samples should
be collected in refrigerated glass containers in accordance with the
requirements of the program. Automatic sampling equipment must be as
free as possible of Tygon tubing and other potential sources of
contamination.
9.2 All samples must be iced or refrigerated at 4 [deg]C from the
time of collection until extraction.
9.3 All samples must be extracted within 7 days of collection and
completely analyzed within 40 days of extraction.\2\

10. Sample Extraction

10.1 Mark the water meniscus on the side of the sample bottle for
later determination of sample volume. Pour the entire sample into a 2-L
separatory funnel.
10.2 Add 60 mL of methylene chloride to the sample bottle, seal, and
shake 30 s to rinse the inner surface. Transfer the solvent to the
separatory funnel and extract the sample by shaking the funnel for 2
min. with periodic venting to release excess pressure. Allow the organic
layer to separate from the water phase for a minimum of 10 min. If the
emulsion interface between layers is more than one-third the volume of
the solvent layer, the analyst must employ mechanical techniques to
complete the phrase separation. The optimum technique depends upon the
sample, but may include stirring, filtration of the emulsion through
glass wool, centrifugation, or other physical methods. Collect the
methylene chloride extract in a 250-mL Erlenmeyer flask.
10.3 Add a second 60-mL volume of methylene chloride to the sample
bottle and repeat the extraction procedure a second time, combining the
extracts in the Erlenmeyer flask. Perform a third extraction in the same
manner.
10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-
mL concentrator tube to a 500-mL evaporative flask. Other concentrator
devices or techniques may be used in place of the K-D concentrator if
the requirements of Section 8.2 are met.
10.5 Pour the combined extract through a solvent-rinsed drying
column containing about 10 cm of anhydrous sodium sulfate, and collect
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and
column with 20 to 30 mL of methylene chloride to complete the
quantitative transfer.
10.6 Add one or two clean boiling chips to the evaporative flask and
attach a three-ball Snyder column. Prewet the Snyder column by adding
about 1 mL of methylene chloride to the top. Place the K-D apparatus on
a hot water bath (60 to 65 [deg]C) so that the concentrator tube is
partially immersed in the hot water, and the entire lower rounded
surface of the flask is bathed with hot vapor. Adjust the vertical
position of the apparatus and the water temperature as required to
complete the concentration in 15 to 20 min. At the proper rate of
distillation the balls of the column will actively chatter but the
chambers will not flood with condensed solvent. When the apparent volume
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain
and cool for at least 10 min.
10.7 Increase the temperature of the hot water bath to about 80
[deg]C. Momentarily remove the Snyder column, add 50 mL of hexane and a
new boiling chip, and reattach the Snyder column. Concentrate the
extract as in Section 10.6, except use hexane to prewet the column. The
elapsed time of concentration should be 5 to 10 min.
10.8 Remove the Snyder column and rinse the flask and its lower
joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL
syringe is recommended for this operation. Adjust the extract volume to
10 mL. Stopper the concentrator tube and store refrigerated if further
processing will not be performed immediately. If the extract will be
stored longer than two days, it should be transferred to a Teflon-sealed
screw-cap vial. If the sample extract requires no further cleanup,
proceed with gas chromatographic analysis (Section 12). If the sample
requires further cleanup, proceed to Section 11.
10.9 Determine the original sample volume by refilling the sample
bottle to the mark and transferring the liquid to a 1000-mL graduated
cylinder. Record the sample volume to the nearest 5 mL.

11. Cleanup and Separation

11. Cleanup procedures may not be necessary for a relatively clean
sample matrix. If particular circumstances demand the use

[[Page 102]]

of a cleanup procedure, the analyst may use either procedure below or
any other appropriate procedure. However, the analyst first must
demonstrate that the requirements of Section 8.2 can be met using the
method as revised to incorporate the cleanup procedure.
11.2 If the entire extract is to be cleaned up by one of the
following procedures, it must be concentrated to 2.0 mL. To the
concentrator tube in Section 10.8, add a clean boiling chip and attach a
two-ball micro-Snyder column. Prewet the column by adding about 0.5 mL
of hexane to the top. Place the micro-K-D apparatus on a hot water bath
(80 [deg]C) so that the concentrator tube is partially immersed in the
hot water. Adjust the vertical position of the apparatus and the water
temperature as required to complete the concentration in 5 to 10 min. At
the proper rate of distillation the balls of the column will actively
chatter but the chambers will not flood. When the apparent volume of
liquid reaches about 0.5 mL, remove the K-D apparatus and allow it to
drain and cool for at least 10 min. Remove the micro-Snyder column and
rinse its lower joint into the concentrator tube with 0.2 mL of hexane.
Adjust the final volume to 2.0 mL and proceed with one of the following
cleanup procedures.
11.3 Florisil column cleanup for phthalate esters:
11.3.1 Place 10 g of Florisil into a chromatographic column. Tap the
column to settle the Florisil and add 1 cm of anhydrous sodium sulfate
to the top.
11.3.2 Preelute the column with 40 mL of hexane. The rate for all
elutions should be about 2 mL/min. Discard the eluate and just prior to
exposure of the sodium sulfate layer to the air, quantitatively transfer
the 2-mL sample extract onto the column using an additional 2 mL of
hexane to complete the transfer. Just prior to exposure of the sodium
sulfate layer to the air, add 40 mL of hexane and continue the elution
of the column. Discard this hexane eluate.
11.3.3 Next, elute the column with 100 mL of 20% ethyl ether in
hexane (V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator
tube. Concentrate the collected fraction as in Section 10.6. No solvent
exchange is necessary. Adjust the volume of the cleaned up extract to 10
mL in the concentrator tube and analyze by gas chromatography (Section
12).
11.4 Alumina column cleanup for phthalate esters:
11.4.1 Place 10 g of alumina into a chromatographic column. Tap the
column to settle the alumina and add 1 cm of anhydrous sodium sulfate to
the top.
11.4.2 Preelute the column with 40 mL of hexane. The rate for all
elutions should be about 2 mL/min. Discard the eluate and just prior to
exposure of the sodium sulfate layer to the air, quantitatively transfer
the 2-mL sample extract onto the column using an additional 2 mL of
hexane to complete the transfer. Just prior to exposure of the sodium
sulfate layer to the air, add 35 mL of hexane and continue the elution
of the column. Discard this hexane eluate.
11.4.3 Next, elute the column with 140 mL of 20% ethyl ether in
hexane (V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator
type. Concentrate the collected fraction as in Section 10.6. No solvent
exchange is necessary. Adjust the volume of the cleaned up extract to 10
mL in the concentrator tube and analyze by gas chromatography (Section
12).

12. Gas Chromatography

12.1 Table 1 summarizes the recommended operating conditions for the
gas chromatograph. Included in this table are retention times and MDL
that can be achieved under these conditions. Examples of the separations
achieved by Column 1 are shown in Figures 1 and 2. Other packed or
capillary (open-tubular) columns, chromatographic conditions, or
detectors may be used if the requirements of Section 8.2 are met.
12.2 Calibrate the system daily as described in Section 7.
12.3 If the internal standard calibration procedure is being used,
the internal staldard must be added to the sample extract and mixed
thoroughly immediately before injection into the gas chromatograph.
12.4 Inject 2 to 5 [mu]L of the sample extract or standard into the
gas-chromatograph using the solvent-flush technique.\11\ Smaller (1.0
[mu]L) volumes may be injected if automatic devices are employed. Record
the volume injected to the nearest 0.05 [mu]L, and the resulting peak
size in area or peak height units.
12.5 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
can be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.
12.6 If the response for a peak exceeds the working range of the
system, dilute the extract and reanalyze.
12.7 If the measurement of the peak response is prevented by the
presence of interferences, further cleanup is required.

13. Calculations

13.1 Determine the concentration of individual compounds in the
sample.

[[Page 103]]

13.1.1 If the external standard calibration procedure is used,
calculate the amount of material injected from the peak response using
the calibration curve or calibration factor determined in Section 7.2.2.
The concentration in the sample can be calculated from Equation 2.
[GRAPHIC] [TIFF OMITTED] TC15NO91.103

Equation 2

where:
A=Amount of material injected (ng).
Vi=Volume of extract injected ([mu]L).
Vt=Volume of total extract ([mu]L).
Vs=Volume of water extracted (mL).

Equation 3

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Is=Amount of internal standard added to each extract ([mu]g).
Vo=Volume of water extracted (L).

13.2 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

14. Method Performance

14.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and reported with 99%
confidence that the value is above zero.\1\ The MDL concentrations
listed in Table 1 were obtained using reagent water.\12\ Similar results
were achieved using representative wastewaters. The MDL actually
achieved in a given analysis will vary depending on instrument
sensitivity and matrix effects.
14.2 This method has been tested for linearity of spike recovery
from reagent water and has been demonstrated to be applicable over the
concentration range from 5 x MDL to 1000 x MDL with the following
exceptions: dimethyl and diethyl phthalate recoveries at 1000 x MDL were
low (70%); bis-2-ethylhexyl and di-n-octyl phthalate recoveries at 5 x
MDL were low (60%).\12\
14.3 This method was tested by 16 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
at six concentrations over the range 0.7 to 106 [mu]g/L.\13\ Single
operator precision, overall precision, and method accuracy were found to
be directly related to the concentration of the parameter and
essentially independent of the sample matrix. Linear equations to
describe these relationships are presented in Table 3.

References

1. 40 CFR part 136, appendix B.
2. ``Determination of Phthalates in Industrial and Muncipal
Wastewaters,'' EPA 600/4-81-063, National Technical Information Service,
PB81-232167, Springfield, Virginia 22161, July 1981.
3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard
Practices for Preparation of Sample Containers and for Preservation of
Organic Constituents,'' American Society for Testing and Materials,
Philadelphia.
4. Giam, C.S., Chan, H.S., and Nef, G.S. ``Sensitive Method for
Determination of Phthalate Ester Plasticizers in Open-Ocean Biota
Samples,'' Analytical Chemistry, 47, 2225 (1975).
5. Giam, C.S., and Chan, H.S. ``Control of Blanks in the Analysis of
Phthalates in Air and Ocean Biota Samples,'' U.S. National Bureau of
Standards, Special Publication 442, pp. 701-708, 1976.
6. ``Carcinogens--Working with Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
7. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
8. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
9. Provost L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3 is two times the value 1.22
derived in this report.)
10. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard
Practices for Sampling Water,'' American Society for Testing and
Materials, Philadelphia.
11. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis;
Some Practical Aspects,'' Journal of the Association of Official
Analytical Chemists, 48, 1037 (1965).
12. ``Method Detection Limit and Analytical Curve Studies, EPA
Methods 606, 607, and 608,'' Special letter report for EPA Contract 68-
03-2606, U.S. Environmental Protection Agency, Environmental Monitoring
and Support Laboratory, Cincinnati, Ohio 45268, June 1980.

[[Page 104]]

13. ``EPA Method Study 16 Method 606 (Phthalate Esters),'' EPA 600/
4-84-056, National Technical Information Service, PB84-211275,
Springfield, Virginia 22161, June 1984.

Table 1--Chromatographic Conditions and Method Detection Limits
------------------------------------------------------------------------
Retention time (min) Method
---------------------------- detection
Parameter limit ([mu]g/
Column 1 Column 2 L)
------------------------------------------------------------------------
Dimethyl phthalate............ 2.03 0.95 0.29
Diethyl phthalate............. 2.82 1.27 0.49
Di-n-butyl phthalate.......... 8.65 3.50 0.36
Butyl benzyl phthalate........ a 6.94 a 5.11 0.34
Bis(2-ethylhexyl) phthalate... a 8.92 a 10.5 2.0
Di-n-octyl phthalate.......... a 16.2 a 18.0 3.0
------------------------------------------------------------------------
Column 1 conditions: Supelcoport (100/120 mesh) coated with 1.5% SP-2250/
1.95% SP-2401 packed in a 1.8 m long x 4 mm ID glass column with 5%
methane/95% argon carrier gas at 60 mL/min flow rate. Column
temperature held isothermal at 180[deg]C, except where otherwise
indicated.
Column 2 conditions: Supelcoport (100/120 mesh) coated with 3% OV-1
packed in a 1.8 m long x 4 mm ID glass column with 5% methane/95%
argon carrier gas at 60 mL/min flow rate. Column temperature held
isothermal at 200 [deg]C, except where otherwise indicated.
a 220 [deg]C column temperature.

Table 2--QC Acceptance Criteria--Method 606
----------------------------------------------------------------------------------------------------------------
Test Limit for Range for Range for
Parameter conc. s ([mu]g/ X ([mu]g/ P, Ps
([mu]g/L) L) L) (percent)
----------------------------------------------------------------------------------------------------------------
Bis(2-ethylhexyl) phthalate........................................ 50 38.4 1.2-55.9 D-158
Butyl benzyl phthalate............................................. 10 4.2 5.7-11.0 30-136
Di-n-butyl phthalate............................................... 25 8.9 10.3-29.6 23-136
Diethyl phthalate.................................................. 25 9.0 1.9-33.4 D-149
Dimethyl phathalate................................................ 25 9.5 1.3-35.5 D-156
Di-n-octyl phthalate............................................... 50 13.4 D-50.0 D-114
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).
D=Detected; result must be greater than zero.

Table 3--Method Accuracy and Precision as Functions of Concentration--Method 606
----------------------------------------------------------------------------------------------------------------
Accuracy, as Single analyst Overall
Parameter recovery, X' precision, sr' precision, S'
([mu]g/L) ([mu]g/L) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
Bis(2-ethylhexyl) phthalate..................................... 0.53C+2.02 0.80X-2.54 0.73X-0.17
Butyl benzyl phthalate.......................................... 0.82C+0.13 0.26X+0.04 0.25X+0.07
Di-n-butyl phthalate............................................ 0.79C+0.17 0.23X+0.20 0.29X+0.06
Diethyl phthalate............................................... 0.70C+0.13 0.27X+0.05 0.45X+0.11
Dimethyl phthalate.............................................. 0.73C+0.17 0.26X+0.14 0.44X+0.31
Di-n-octyl phthalate............................................ 0.35C-0.71 0.38X+0.71 0.62X+0.34
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
sr'=Expected single analyst standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
C=True value for the concentration, in [mu]g/L.
X=Average recovery found for measurements of samples containing a concentration of C, in [mu]g/L.

[[Page 105]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.015

[[Page 106]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.016

[[Page 107]]

Method 607--Nitrosamines

1. Scope and Application

1.1 This method covers the determination of certain nitrosamines.
The following parameters can be determined by this method:

------------------------------------------------------------------------
Parameter Storet No. CAS No.
------------------------------------------------------------------------
N-Nitrosodimethylamine........................ 34438 62-75-9
N-Nitrosodiphenylamine........................ 34433 86-30-6
N-Nitrosodi-n-propylamine..................... 34428 621-64-7
------------------------------------------------------------------------

1.2 This is a gas chromatographic (GC) method applicable to the
determination of the parameters listed above in municipal and industrial
discharges as provided under 40 CFR 136.1. When this method is used to
analyze unfamiliar samples for any or all of the compmunds above,
compound identifications should be supported by at least one additional
qualitative technique. This method describes analytical conditimns for a
second gas chromatographic column that can be used to confirm
measurements made with the primary column. Method 625 provides gas
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the
qualitative and quantitative confirmation of results for N-nitrosodi-n-
propylamine. In order to confirm the presence of N-nitrosodiphenylamine,
the cleanup procedure specified in Section 11.3 or 11.4 must be used. In
order to confirm the presence of N-nitrosodimethylamine by GC/MS, Column
1 of this method must be substituted for the column recommended in
Method 625. Confirmation of these parameters using GC-high resolution
mass spectrometry or a Thermal Energy Analyzer is also recommended.
^1,2
1.3 The method detection limit (MDL, defined in Section
14.1)³ for each parameter is listed in Table 1. The MDL for a
specific wastewater may differ from those listed, depending upon the
nature of interferences in the sample matrix.
1.4 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.5 This method is restricted to use by or under the supervision of
analysts experienced in the use of a gas chromatograph and in the
interpretation of gas chromatograms. Each analyst must demonstrate the
ability to generate acceptable results with this method using the
procedure described in Section 8.2.

2. Summary of Method

2.1 A measured volume of sample, approximately 1-L, is extracted
with methylene chloride using a separatory funnel. The methylene
chloride extract is washed with dilute hydrochloric acid to remove free
amines, dried, and concentrated to a volume of 10 mL or less. After the
extract has been exchanged to methanol, it is separated by gas
chromatography and the parameters are then measured with a nitrogen-
phosphorus detector.⁴
2.2 The method provides Florisil and alumina column cleanup
procedures to separate diphenylamine from the nitrosamines and to aid in
the elimination of interferences that may be encountered.

3. Interferences

3.1 Method interferences may be caused by contaminants in solvents,
reagents, glassware, and other sample processing hardware that lead to
discrete artifacts and/or elevated baselines in gas chromatograms. All
of these materials must be routinely demonstrated to be free from
interferences under the conditions of the analysis by running laboratory
reagent blanks as described in Section 8.1.3.
3.1.1 Glassware must be scrupulously cleaned.⁵ Clean all
glassware as soon as possible after use by rinsing with the last solvent
used in it. Solvent rinsing should be followed by detergent washing with
hot water, and rinses with tap water and distilled water. The glassware
should then be drained dry, and heated in a muffle furnace at 400 [deg]C
for 15 to 30 min. Solvent rinses with acetone and pesticide quality
hexane may be substituted for the muffle furnace heating. Volumetric
ware should not be heated in a muffle furnace. After drying and cooling,
glassware should be sealed and stored in a clean environment to prevent
any accumulation of dust or other contaminants. Store inverted or capped
with aluminum foil.
3.1.2 The use of high purity reagents and solvents helps to minimize
interference problems. Purification of solvents by distillation in all-
glass systems may be required.
3.2 Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary
considerably from source to source, depending upon the nature and
diversity of the industrial complex or municipality being sampled. The
cleanup procedures in Section 11 can be used to overcome many of these
interferences, but unique samples may require additional cleanup
approaches to achieve the MDL listed in Table 1.
3.3 N-Nitrosodiphenylamine is reported^6-9 to undergo
transnitrosation reactions. Care must be exercised in the heating or
concentrating of solutions containing this compound in the presence of
reactive amines.
3.4 The sensitive and selective Thermal Energy Analyzer and the
reductive Hall detector may be used in place of the nitrogen-phosphorus
detector when interferences are encountered. The Thermal Energy Analyzer
offers the highest selectivity of the non-MS detectors.

[[Page 108]]

4. Safety

4.1 The toxicity or carcinogenicity of each [chyph]reagent used in
this method has not been [chyph]precisely defined; however, each
chemical [chyph]compound should be treated as a potential health hazard.
From this viewpoint, exposure to these chemicals must be reduced to the
lowest possible level by whatever means available. The laboratory is
responsible for maintaining a current awareness file of OSHA regulations
regarding the safe handling of the chemicals specified in this method. A
reference file of material data handling sheets should also be made
available to all personnel involved in the chemical analysis. Additional
references to laboratory safety are available and have been identified
^10-12 for the information of the analyst.
4.2 These nitrosamines are known carcinogens ^13-17,
therefore, utmost care must be exercised in the handling of these
materials. Nitrosamine reference standards and standard solutions should
be handled and prepared in a ventilated glove box within a properly
ventilated room.

5. Apparatus and Materials

5.1 Sampling equipment, for discrete or composite sampling.
5.1.1 Grab sample bottle--1-L or 1-qt, amber glass, fitted with a
screw cap lined with Teflon. Foil may be substituted for Teflon if the
sample is not corrosive. If amber bottles are not available, protect
samples from light. The bottle and cap liner must be washed, rinsed with
acetone or methylene chloride, and dried before use to minimize
contamination.
5.1.2 Automatic sampler (optional)--The sampler must incorporate
glass sample containers for the collection of a minimum of 250 mL of
sample. Sample containers must be kept refrigerated at 4 [deg]C and
protected from light during compositing. If the sampler uses a
peristaltic pump, a minimum length of compressible silicone rubber
tubing may be used. Before use, however, the compressible tubing should
be thoroughly rinsed with methanol, followed by repeated rinsings with
distilled water to minimize the potential for contamination of the
sample. An integrating flowmeter is required to collect flow
proportional composites.
5.2 Glassware (All specifications are suggested. Catalog numbers are
included for illustration only.):
5.2.1 Separatory funnels--2-L and 250-mL, with Teflon stopcock.
5.2.2 Drying column--Chromatographic [chyph]column, approximately
400 mm long x 19 mm [chyph]ID, with coarse frit filter disc.
5.2.3 Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes K-
570050-1025 or equivalent). Calibration must be checked at the volumes
employed in the test. Ground glass stopper is used to prevent
evaporation of extracts.
5.2.4 Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
5.2.5 Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
5.2.6 Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
5.2.7 Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
5.2.8 Chromatographic column--Approximately 400 mm long x 22 mm ID,
with Teflon stopcock and coarse frit filter disc at bottom (Kontes K-
420540-0234 or equivalent), for use in Florisil column cleanup
procedure.
5.2.9 Chromatographic column--Approximately 300 mm long x 10 mm ID,
with Teflon stopcock and coarse frit filter disc at bottom (Kontes K-
420540-0213 or equivalent), for use in alumina column cleanup procedure.
5.3 Boiling chips--Approximately 10/40 mesh. Heat to 400 [deg]C for
30 min or Soxhlet extract with methylene chloride.
5.4 Water bath--Heated, with concentric ring cover, capable of
temperature control (+-2 [deg]C). The bath should be used in a hood.
5.5 Balance--Analytical, capable of accurately weighing 0.0001 g.
5.6 Gas chromatograph--An analytical system complete with gas
chromatograph suitable for on-column injection and all required
accessories including syringes, analytical columns, gases, detector, and
strip-chart recorder. A data system is recommended for measuring peak
areas.
5.6.1 Column 1--1.8 m long x 4 mm ID glass, packed with 10% Carbowax
20 M/2% KOH on Chromosorb W-AW (80/100 mesh) or equivalent. This column
was used to develop the method performance statements in Section 14.
Guidelines for the use of alternate column packings are provided in
Section 12.2.
5.6.2 Column 2--1.8 m long x 4 mm ID glass, packed with 10% SP-2250
on Supel- coport (100/120 mesh) or equivalent.
5.6.3 Detector--Nitrogen-phosphorus, reductive Hall, or Thermal
Energy Analyzer detector.\1,\ \2\ These detectors have proven effective
in the analysis of wastewaters for the parameters listed in the scope
(Section 1.1). A nitrogen-phosphorus detector was used to develop the
method performance statements in Section 14. Guidelines for the use of
alternate detectors are provided in Section 12.2.

6. Reagents

[[Page 109]]

6.3 Sodium thiosulfate--(ACS) Granular.
6.4 Sulfuric acid (1+1)--Slowly, add 50 mL of
H2SO4 (ACS, sp. gr. 1.84) to 50 mL of reagent
water.
6.5 Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at
400 [deg]C for 4 h in a shallow tray.
6.6 Hydrochloric acid (1+9)--Add one volume of concentrated HCl
(ACS) to nine volumes of reagent water.
6.7 Acetone, methanol, methylene chloride, pentane--Pesticide
quality or equivalent.
6.8 Ethyl ether--Nanograde, redistilled in glass if necessary.
6.8.1 Ethyl ether must be shown to be free of peroxides before it is
used as indicated by EM Laboratories Quant test strips. (Available from
Scientific Products Co., Cat No. P1126-8, and other suppliers.)
6.8.2 Procedures recommended for removal of peroxides are provided
with the test strips. After cleanup, 20 mL of ethyl alcohol preservative
must be added to each liter of ether.
6.9 Florisil--PR grade (60/100 mesh). Purchase activated at 1250
[deg]F and store in the dark in glass containers with ground glass
stoppers or foil-lined screw caps. Before use, activate each batch at
least 16 h at 130 [deg]C in a foil-covered glass container and allow to
cool.
6.10 Alumina--Basic activity Super I, W200 series (ICN Life Sciences
Group, No. 404571, or equivalent). To prepare for use, place 100 g of
alumina into a 500-mL reagent bottle and add 2 mL of reagent water. Mix
the alumina preparation thoroughly by shaking or rolling for 10 min and
let it stand for at least 2 h. The preparation should be homogeneous
before use. Keep the bottle sealed tightly to ensure proper activity.
6.11 Stock standard solutions (1.00 [mu]g/[mu]L)--Stock standard
solutions can be prepared from pure standard materials or purchased as
certified solutions.
6.11.1 Prepare stock standard solutions by accurately weighing about
0.0100 g of pure material. Dissolve the material in methanol and dilute
to volume in a 10-mL volumetric flask. Larger volumes can be used at the
convenience of the analyst. When compound purity is assayed to be 96% or
greater, the weight can be used without correction to calculate the
concentration of the stock standard. Commercially prepared stock
standards can be used at any concentration if they are certified by the
manufacturer or by an independent source.
6.11.2 Transfer the stock standard solutions into Teflon-sealed
screw-cap bottles. Store at 4 [deg]C and protect from light. Stock
standard solutions should be checked frequently for signs of degradation
or evaporation, especially just prior to preparing calibration standards
from them.
6.11.3 Stock standard solutions must be replaced after six months,
or sooner if comparison with check standards indicates a problem.
6.12 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

7.1 Establish gas chromatographic operating conditions equivalent to
those given in Table 1. The gas chromatographic system can be calibrated
using the external standard technique (Section 7.2) or the internal
standard technique (Section 7.3).
7.2 External standard calibration procedure:
7.2.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask and diluting to volume
with methanol. One of the external standards should be at a concentraton
near, but above, the MDL (Table 1) and the other concentrations should
correspond to the expected range of concentrations found in real samples
or should define the working range of the detector.
7.2.2 Using injections of 2 to 5 [mu]L, analyze each calibration
standard according to Section 12 and tabulate peak height or area
responses against the mass injected. The results can be used to prepare
a calibration curve for each compound. Alternatively, if the ratio of
response to amount injected (calibration factor) is a constant over the
working range (<10% relative standard deviation, RSD), linearity through
the origin can be assumed and the average ratio or calibration factor
can be used in place of a calibration curve.
7.3 Internal standard calibration procedure--To use this approach,
the analyst must select one or more internal standards that are similar
in analytical behavior to the compounds of interest. The analyst must
further demonstrate that the measurement of the internal standard is not
affected by method or matrix interferences. Because of these
limitations, no internal standard can be suggested that is applicable to
all samples.
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask. To each calibration
standard, add a known constant amount of one or more internal standards,
and dilute to volume with methanol. One of the standards should be at a
concentration near, but above, the MDL and the other concentrations
should correspond to the expected range of concentrations found in real
samples or should define the working range of the detector.

[[Page 110]]

RF= (As)(Cis) (Ais)(Cs)
----------------------------------------------------------------------------------------------------------------

Equation 1

8. Quality Control

8.1 Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements of this program
consist of an initial demonstration of laboratory capability and an
ongoing analysis of spiked samples to evaluate and document data
quality. The laboratory must maintain records to document the quality of
data that is generated. Ongoing data quality checks are compared with
established performance criteria to determine if the results of analyses
meet the performance characteristics of the method. When results of
sample spikes indicate atypical method performance, a quality control
check standard must be analyzed to confirm that the measurements were
performed in an in-control mode of operation.
8.1.1 The analyst must make an initial, one-time, demonstration of
the ability to generate acceptable accuracy and precision with this
method. This ability is established as described in Section 8.2.
8.1.2 In recognition of advances that are occurring in
chromatography, the analyst is permitted certain options (detailed in
Sections 10.4, 11.1, and 12.2) to improve the separations or lower the
cost of measurements. Each time such a modification is made to the
method, the analyst is required to repeat the procedure in Section 8.2.
8.1.3 Before processing any samples, the analyst must analyze a
reagent water blank to demonstrate that interferences from the
analytical system and glassware are under control. Each time a set of
samples is extracted or reagents are changed, a reagent water blank must
be processed as a safeguard against laboratory contamination.
8.1.4 The laboratory must, on an ongoing basis, spike and analyze a
minimum of 10% of all samples to monitor and evaluate laboratory data
quality. This procedure is described in Section 8.3.
8.1.5 The laboratory must, on an ongoing basis, demonstrate through
the analyses of quality control check standards that the operation of
the measurement system is in control. This procedure is described in
Section 8.4. The frequency of the check standard analyses is equivalent
to 10% of all samples analyzed but may be reduced if spike recoveries
from samples (Section 8.3) meet all specified quality control criteria.
8.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is described in
Section 8.5.
8.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
8.2.1 A quality control (QC) check sample concentrate is required
containing each parameter of interest at a concentration of 20 [mu]g/mL
in methanol. The QC check sample concentrate must be obtained from the
U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory in Cincinnati, Ohio, if available. If not available
from that source, the QC check sample concentrate must be obtained from
another external source. If not available from either source above, the
QC check sample concentrate must be prepared by the laboratory using
stock standards prepared independently from those used for calibration.
8.2.2 Using a pipet, prepare QC check samples at a concentration of
20 [mu]g/L by adding 1.00 mL of QC check sample concentrate to each of
four 1-L aliquots of reagent water.
8.2.3 Analyze the well-mixed QC check samples according to the
method beginning in Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter
using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively,

[[Page 111]]

found in Table 2. If s and X for all parameters of interest meet the
acceptance criteria, the system performance is acceptable and analysis
of actual samples can begin. If any individual s exceeds the precision
limit or any individual X falls outside the range for accuracy, the
system performance is unacceptable for that parameter. Locate and
correct the source of the problem and repeat the test for all parameters
of interest beginning with Section 8.2.2.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at 20 [mu]g/L or 1 to 5 times higher than the background
concentration determined in Section 8.3.2, whichever concentration would
be larger.
8.3.1.3 If it is impractical to determine background levels before
spiking (e.g., maximum holding times will be exceeded), the spike
concentration should be (1) the regulatory concentration limit, if any;
or, if none (2) the larger of either 5 times higher than the expected
background concentration or 20 [mu]g/L.
8.3.2 Analyze one sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second sample aliquot with 1.0 mL
of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100(A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 2. These acceptance
criteria were caluclated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.\18\ If spiking was performed at a concentration lower than 20
[mu]g/L, the analyst must use either the QC acceptance criteria in Table
2, or optional QC acceptance criteria caluclated for the specific spike
concentration. To calculate optional acceptance crtieria for the
recovery of a parameter: (1) Calculate accuracy (X') using the equation
in Table 3, substituting the spike concentration (T) for C; (2)
calculate overall precision (S') using the equation in Table 3,
substituting X' for X; (3) calculate the range for recovery at the spike
concentration as (100 X'/T) +- 2.44(100 S'/T)%.\18\
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory.
8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The
QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
2. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2sp to P+2sp.
If P=90% and sp=10%, for example, the accuracy interval is
expressed as 70-110%. Update the accuracy assessment for each parameter
on a regular basis (e.g. after each five to ten new accuracy
measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices

[[Page 112]]

for use with this method. The specific practices that are most
productive depend upon the needs of the laboratory and the nature of the
samples. Field duplicates may be analyzed to assess the precision of the
environmental measurements. When doubt exists over the identification of
a peak on the chromatogram, confirmatory techniques such [chyph]as gas
chromatography with a dissimilar [chyph]column, specific element
detector, or mass [chyph]spectrometer must be used. Whenever possible,
the laboratory should analyze standard reference materials and
participate in relevant performance evaluation studies.

9. Sample Collection, Preservation, and Handling

9.1 Grab samples must be collected in glass [chyph]containers.
Conven[chyph]tional sampling practices \19\ should be [chyph]followed,
except that the bottle must not be pre[chyph]rinsed with sample before
collection. Composite sam[chyph]ples should be collected in refrigerated
glass containers in accordance with the requirements of the program.
Automatic sampling equipment must be as free as possible of Tygon tubing
and other potential sources of contamination.
9.2 All samples must be iced or refrigerated at 4 [deg]C from the
time of collection until extraction. Fill the sample bottles and, if
residual chlorine is present, add 80 mg of sodium thiosulfate per liter
of sample and mix well. EPA Methods 330.4 and 330.5 may be used for
measurement of residual chlorine.\20\ Field test kits are available for
this purpose. If N-nitrosodiphenylamine is to be determined, adjust the
sample pH to 7 to 10 with sodium hydroxide solution or sulfuric acid.
9.3 All samples must be extracted within 7 days of collection and
completely analyzed within 40 days of extraction.\4\
9.4 Nitrosamines are known to be light sen[chyph]sitive.\7\ Samples
should be stored in amber or foil-wrapped bottles in order to minimize
photolytic decomposition.

10. Sample Extraction

10.1 Mark the water meniscus on the side of the sample bottle for
later determination of sample volume. Pour the entire sample into a 2-L
separatory funnel. Check the pH of the sample with wide-range pH paper
and adjust to within the range of 5 to 9 with sodium hydroxide solution
or sulfuric acid.
10.2 Add 60 mL of methylene chloride to the sample bottle, seal, and
shake 30 s to rinse the inner surface. Transfer the solvent to the
separatory funnel and extract the sample by shaking the funnel for 2 min
with periodic venting to release excess pressure. Allow the organic
layer to separate from the water phase for a minimum of 10 min. If the
emulsion interface between layers is more than one-third the volume of
the solvent layer, the analyst must employ mechanical techniques to
complete the phase separation. The optimum technique depends upon the
sample, but may include stirring, filtration of the emulsion through
glass wool, centrifugation, or other physical methods. Collect the
methylene chloride extract in a 250-mL Erlenmeyer flask.
10.3 Add a second 60-mL volume of methylene chloride to the sample
bottle and repeat the extraction procedure a second time, combining the
extracts in the Erlenmeyer flask. Perform a third extraction in the same
manner.
10.4 Assemble a Kuderna-Danish (K-D) con[chyph]centrator by
attaching a 10-mL concentra[chyph]tor tube to a 500-mL evaporative
flask. Other [chyph]concentration devices or techniques may be used in
place of the K-D concentrator if the requirements of Section 8.2 are
met.
10.5 Add 10 mL of hydrochloric acid to the combined extracts and
shake for 2 min. Allow the layers to separate. Pour the combined extract
through a solvent-rinsed drying column containing about 10 cm of
anhydrous sodium sulfate, and collect the extract in the K-D
concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of
methylene chloride to complete the quantitative transfer.
10.6 Add one or two clean boiling chips to the evaporative flask and
attach a three-ball Snyder column. Prewet the Snyder column by adding
about 1 mL of methylene chloride to the top. Place the K-D apparatus on
a hot water bath (60 to 65[deg]C) so that the concentrator tube is
partially immersed in the hot water, and the entire lower rounded
surface of the flask is bathed with hot vapor. Adjust the vertical
position of the apparatus and the water temperature as required to
complete the concentration in 15 to 20 min. At the proper rate of
distillation the balls of the column will actively chatter but the
chambers will not flood with condensed solvent. When the apparent volume
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain
and cool for at least 10 min.
10.7 Remove the Snyder column and rinse the flask and its lower
joint into the concentrator tube with 1 to 2 mL of methylene chloride. A
5-mL syringe is recommended for this operation. Stopper the concentrator
tube and store refrigerated if further processing will not be performed
immediately. If the extract will be stored longer than two days, it
should be transferred to a Teflon-sealed screw-cap vial. If N-
nitro[chyph]sodi[chyph]phe[chyph]nylamine is to be measured by gas
chromatography, the analyst must first use a cleanup column to eliminate
diphenylamine interference (Section 11). If N-nitrosodiphenylamine is of
no interest, the analyst may proceed directly with gas chromatographic
analysis (Section 12).

[[Page 113]]

10.8 Determine the original sample volume by refilling the sample
bottle to the mark and transferring the liquid to a 1000-
mL graduated cylinder. Record the sample volume to the nearest 5 mL.

11. Cleanup and Separation

11.1 Cleanup procedures may not be necessary for a relatively clean
sample matrix. If particular circumstances demand the use of a cleanup
procedure, the analyst may use either procedure below or any other
appropriate procedure. However, the analyst first must demonstrate that
the requirements of Section 8.2 can be met using the method as revised
to incorporate the cleanup procedure. Diphenylamine, if present in the
original sample extract, must be separated from the nitrosamines if N-
nitrosodiphenylamine is to be determined by this method.
11.2 If the entire extract is to be cleaned up by one of the
following procedures, it must be concentrated to 2.0 mL. To the
concentrator tube in Section 10.7, add a clean boiling chip and attach a
two-ball micro-Snyder column. Prewet the column by adding about 0.5 mL
of methylene chloride to the top. Place the micr-K-D apparatus on a hot
water bath (60 to 65 [deg]C) so that the concentrator tube is partially
immersed in the hot water. Adjust the vertical position of the apparatus
and the water temperature as required to complete the concentration in 5
to 10 min. At the proper rate of distillation the balls of the column
will actively chatter but the chambers will not flood. When the apparent
volume of liquid reaches about 0.5 mL, remove the K-D apparatus and
allow it to drain and cool for at least 10 min. Remove the micro-Snyder
column and rinse its lower joint into the concentrator tube with 0.2 mL
of methylene chloride. Adjust the final volume to 2.0 mL and proceed
with one of the following cleanup procedures.
11.3 Florisil column cleanup for nitro[chyph]samines:
11.3.1 Place 22 g of activated Florisil into a 22-mm ID
chromatographic column. Tap the column to settle the Florisil and add
about 5 mm of anhydrous sodium sulfate to the top.
11.3.2 Preelute the column with 40 mL of ethyl ether/pentane
(15+85)(V/V). Discard the eluate and just prior to exposure of the
sodium sulfate layer to the air, quantitatively transfer the 2-mL sample
extract onto the column using an additional 2 mL of pentane to complete
the transfer.
11.3.3 Elute the column with 90 mL of ethyl ether/pentane (15+85)(V/
V) and discard the eluate. This fraction will contain the diphenylamine,
if it is present in the extract.
11.3.4 Next, elute the column with 100 mL of acetone/ethyl ether
(5+95)(V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator
tube. This fraction will contain all of the nitrosamines listed in the
scope of the method.
11.3.5 Add 15 mL of methanol to the collected fraction and
concentrate as in Section 10.6, except use pentane to prewet the column
and set the water bath at 70 to 75 [deg]C. When the apparatus is cool,
remove the Snyder column and rinse the flask and its lower joint into
the concentrator tube with 1 to 2 mL of pentane. Analyze by gas
chromatography (Section 12).
11.4 Alumina column cleanup for nitro[chyph]samines:
11.4.1 Place 12 g of the alumina preparation (Section 6.10) into a
10-mm ID chromatographic column. Tap the column to settle the alumina
and add 1 to 2 cm of anhydrous sodium sulfate to the top.
11.4.2 Preelute the column with 10 mL of ethyl ether/pentane
(3+7)(V/V). Discard the eluate (about 2 mL) and just prior to exposure
of the sodium sulfate layer to the air, quantitatively transfer the 2 mL
sample extract onto the column using an additional 2 mL of pentane to
complete the transfer.
11.4.3 Just prior to exposure of the sodium sulfate layer to the
air, add 70 mL of ethyl ether/pentane (3+7)(V/V). Discard the first 10
mL of eluate. Collect the remainder of the eluate in a 500-mL K-D flask
equipped with a 10 mL concentrator tube. This fraction contains N-
nitrosodiphenylamine and probably a small amount of N-nitrosodi-n-
propylamine.
11.4.4 Next, elute the column with 60 mL of ethyl ether/pentane
(1+1)(V/V), collecting the eluate in a second K-D flask equipped with a
10-mL concentrator tube. Add 15 mL of methanol to the K-D flask. This
fraction will contain N-nitrosodimethylamine, most of the N-nitrosodi-n-
propylamine and any diphenylamine that is present.
11.4.5 Concentrate both fractions as in Section 10.6, except use
pentane to prewet the column. When the apparatus is cool, remove the
Snyder column and rinse the flask and its lower joint into the
concentrator tube with 1 to 2 mL of pentane. Analyze the fractions by
gas chromatography (Section 12).

12. Gas Chromatography

12.1 N-nitrosodiphenylamine completely reacts to form diphenylamine
at the normal operating temperatures of a GC injection port (200 to 250
[deg]C). Thus, N-nitro[chyph]sodi[chyph]phenylamine is chromatographed
and detected as di[chyph]phe[chyph]nyla[chyph]mine. Accurate
determination depends on removal of di[chyph]phe[chyph]nyla[chyph]mine
that may be present in the original extract prior to GC analysis (See
Section 11).
12.2 Table 1 summarizes the recommended operating conditions for the
gas chromatograph. Included in this table are retention times and MDL
that can be achieved under these conditions. Examples of the separations
achieved by Column 1 are shown in

[[Page 114]]

Figures 1 and 2. Other packed or capillary (open-tubular) columns,
chromatographic conditions, or detectors may be used if the requirements
of Section 8.2 are met.
12.3 Calibrate the system daily as described in Section 7.
12.4 If the extract has not been subjected to one of the cleanup
procedures in Section 11, it is necessary to exchange the solvent from
methylene chloride to methanol before the thermionic detector can be
used. To a 1 to 10-mL volume of methylene chloride extract in a
concentrator tube, add 2 mL of methanol and a clean boiling chip. Attach
a two-ball micro-Snyder column to the concentrator tube. Prewet the
column by adding about 0.5 mL of methylene chloride to the top. Place
the micro-K-D apparatus on a boiling (100 [deg]C) water bath so that the
concentrator tube is partially immersed in the hot water. Adjust the
vertical position of the apparatus and the water temperature as required
to complete the concentration in 5 to 10 min. At the proper rate of
distillation the balls of the column will actively chatter but the
chambers will not flood. When the apparent volume of liquid reaches
about 0.5 mL, remove the K-D apparatus and allow it to drain and cool
for at least 10 min. Remove the micro-Snyder column and rinse its lower
joint into the concentrator tube with 0.2 mL of methanol. Adjust the
final volume to 2.0 mL.
12.5 If the internal standard calibration procedure is being used,
the internal standard must be added to the sample extract and mixed
thoroughly immediately before injection into the gas chromatograph.
12.6 Inject 2 to 5 [mu]L of the sample extract or standard into the
gas chromatograph using the solvent-flush technique.\21\ Smaller (1.0
[mu]L) volumes may be injected if automatic devices are employed. Record
the volume injected to the nearest 0.05 [mu]L, and the resulting peak
size in area or peak height units.
12.7 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
can be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.
12.8 If the response for a peak exceeds the working range of the
system, dilute the extract and reanalyze.
12.9 If the measurement of the peak response is prevented by the
presence of interferences, further cleanup is required.

13. Calculations

Equation 2

where:
A=Amount of material injected (ng).
Vi=Volume of extract injected ([mu]L).
Vt=Volume of total extract ([mu]L).
Vs=Volume of water extracted (mL).

Equation 3

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Is=Amount of internal standard added to each extract ([mu]g).
Vo=Volume of water extracted (L).

13.2 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

14. Method Performance

14.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and reported with 99%
confidence that the value is above zero.\3\ The MDL concentrations
listed in Table 1 were obtained using reagent water.\22\ Similar results
were achieved using representative wastewaters. The MDL actually
achieved in a given analysis will vary depending on instrument
sensitivity and matrix effects.
14.2 This method has been tested for linearity of spike recovery
from reagent water and has been demonstrated to be applicable over the
concentration range from 4 x MDL to 1000 x MDL.\22\
14.3 This method was tested by 17 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
at six concentrations

[[Page 115]]

over the range 0.8 to 55 [mu]g/L.\23\ Single operator precision, overall
precision, and method accuracy were found to be directly related to the
concentration of the parameter and essentially independent of the sample
matrix. Linear equations to describe these relationships are presented
in Table 3.

References

1. Fine, D.H., Lieb, D., and Rufeh, R. ``Principle of Operation of
the Thermal Energy Analyzer for the Trace Analysis of Volatile and Non-
volatile N-nitroso Compounds,'' Journal of Chromatography, 107, 351
(1975).
2. Fine, D.H., Hoffman, F., Rounbehler, D.P., and Belcher, N.M.
``Analysis of N-nitroso Compounds by Combined High Performance Liquid
Chromatography and Thermal Energy Analysis,'' Walker, E.A., Bogovski, P.
and Griciute, L., Editors, N-nitroso Compounds--Analysis and Formation,
Lyon, International Agency for Research on Cancer (IARC Scientific
Publications No. 14), pp. 43-50 (1976).
3. 40 CFR part 136, appendix B.
4. ``Determination of Nitrosamines in Industrial and Municipal
Wastewaters,'' EPA 600/4-82-016, National Technical Information Service,
PB82-199621, Springfield, Virginia 22161, April 1982.
5. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard
Practices for Preparation of Sample Containers and for Preservation of
Organic Constituents,'' American Society for Testing and Materials,
Philadelphia.
6. Buglass, A.J., Challis, B.C., and Osborn, M.R. ``Transnitrosation
and Decomposition of Nitrosamines,'' Bogovski, P. and Walker, E.A.,
Editors, N-nitroso Compounds in the Environment, Lyon, International
Agency for Research on Cancer (IARC Scientific Publication No. 9), pp.
94-100 (1974).
7. Burgess, E.M., and Lavanish, J.M. ``Photochemical Decomposition
of N-nitrosamines,'' Tetrahedon Letters, 1221 (1964)
8. Druckrey, H., Preussmann, R., Ivankovic, S., and Schmahl, D.
``Organotrope Carcinogene Wirkungen bei 65 Verschiedenen N-
NitrosoVerbindungen an BD-Ratten,'' Z. Krebsforsch., 69, 103 (1967).
9. Fiddler, W. ``The Occurrence and Determination of N-nitroso
Compounds,'' Toxicol. Appl. Pharmacol., 31, 352 (1975).
10. ``Carcinogens--Working With Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
11. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
Part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
12. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
13. Lijinsky, W. ``How Nitrosamines Cause Cancer,'' New Scientist,
73, 216 (1977).
14. Mirvish, S.S. ``N-Nitroso compounds: Their Chemical and in vivo
Formation and Possible Importance as Environmental Carcinogens,'' J.
Toxicol. Environ. Health, 3, 1267 (1977).
15. ``Reconnaissance of Environmental Levels of Nitrosamines in the
Central United States,'' EPA-330/1-77-001, National Enforcement
Investigations Center, U.S. Environmental Protection Agency (1977).
16. ``Atmospheric Nitrosamine Assessment Report,'' Office of Air
Quality Planning and Standards, U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina (1976).
17. ``Scientific and Technical Assessment Report on Nitrosamines,''
EPA-660/6-7-001, Office of Research and Development, U.S. Environmental
Protection Agency (1976).
18. Provost, L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3 is two times the value of 1.22
derived in this report.)
19. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard
Practices for Sampling Water,'' American Society for Testing and
Materials, Philadelphia.
20. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S.
Environmental Protection Agency, Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio 45268, March 1979.
21. Burke, J. A. ``Gas Chromatography for Pesticide Residue
Analysis; Some Practical Aspects,'' Journal of the Association of
Official Analytical Chemists, 48, 1037 (1965).
22. ``Method Detection Limit and Analytical Curve Studies EPA
Methods 606, 607, and 608,'' Special letter report for EPA Contract 68-
03-2606, U.S. Environmental Protection Agency, Environmental Monitoring
and Support Laboratory, Cincinnati, Ohio 45268, June 1980.
23. ``EPA Method Study 17 Method 607--Nitrosamines,'' EPA 600/4-84-
051, National Technical Information Service, PB84-207646, Springfield,
Virginia 22161, June 1984.

[[Page 116]]

Table 1--Chromatographic Conditions and Method Detection Limits
------------------------------------------------------------------------
Retention time (min) Method
-------------------------- detection
Parameter limit
Column 1 Column 2 ([mu]g/L)
------------------------------------------------------------------------
N-Nitrosodimethylamine........... 4.1 0.88 0.15
N-Nitrosodi-n-propylamine........ 12.1 4.2 .46
N-Nitrosodiphenylamine \a\....... \b\ 12.8 \c\ 6.4 .81
------------------------------------------------------------------------
Column 1 conditions: Chromosorb W-AW (80/100 mesh) coated with 10%
Carbowax 20 M/2% KOH packed in a 1.8 m long x 4mm ID glass column with
helium carrier gas at 40 mL/min flow rate. Column temperature held
isothermal at 110 [deg]C, except where otherwise indicated.
Column 2 conditions: Supelcoport (100/120 mesh) coated with 10% SP-2250
packed in a 1.8 m long x 4 mm ID glass column with helium carrier gas
at 40 mL/min flow rate. Column temperature held isothermal at 120
[deg]C, except where otherwise indicated.
\a\ Measured as diphenylamine.
\b\ 220 [deg]C column temperature.
\c\ 210 [deg]C column temperature.

Table 2--QC Acceptance Criteria--Method 607
----------------------------------------------------------------------------------------------------------------
Range for X Range for
Parameter Test conc. Limit for s ([mu]g/L) P, Ps
([mu]g/L) ([mu]g/L) (percent)
----------------------------------------------------------------------------------------------------------------
N-Nitrosodimethylamine...................................... 20 3.4 4.6-20.0 13-109
N-Nitrosodiphenyl........................................... 20 6.1 2.1-24.5 D-139
N-Nitrosodi-n-propylamine................................... 20 5.7 11.5-26.8 45-146
----------------------------------------------------------------------------------------------------------------
s=Standard deviation for four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).
D=Detected; result must be greater than zero.

Table 3--Method Accuracy and Precision as Functions of Concentration--Method 607
----------------------------------------------------------------------------------------------------------------
Accuracy, as Single analyst Overall
Parameter recovery, X' precision, sr' precision, S'
([mu]g/L) ([mu]g/L) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
N-Nitrosodimethylamine.......................................... 0.37C+0.06 0.25X-0.04 0.25X+0.11
N-Nitrosodiphenylamine.......................................... 0.64C+0.52 0.36X-1.53 0.46X-0.47
N-Nitrosodi-n-propylamine....................................... 0.96C-0.07 0.15X+0.13 0.21X+0.15
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
sr'=Expected single analyst standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
C=True value for the concentration, in [mu]g/L.
X=Average recovery found for measurements of samples containing a concentration of C, in [mu]g/L.

[[Page 117]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.017

[[Page 118]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.018

[[Page 119]]

Method 608--Organochlorine Pesticides and PCBs

1. Scope and Application

1.1 This method covers the determination of certain organochlorine
pesticides and PCBs. The following parameters can be determined by this
method:

------------------------------------------------------------------------
Parameter STORET No. CAS No.
------------------------------------------------------------------------
Aldrin...................................... 39330 309-00-2
[alpha]-BHC................................. 39337 319-84-6
[beta]-BHC.................................. 39338 319-85-7
[delta]-BHC................................. 34259 319-86-8
[gamma]-BHC................................. 39340 58-89-9
Chlordane................................... 39350 57-74-9
4,4'-DDD.................................... 39310 72-54-8
4,4'-DDE.................................... 39320 72-55-9
4,4'-DDT.................................... 39300 50-29-3
Dieldrin.................................... 39380 60-57-1
Endosulfan I................................ 34361 959-98-8
Endosulfan II............................... 34356 33212-65-9
Endosulfan sulfate.......................... 34351 1031-07-8
Eldrin...................................... 39390 72-20-8
Endrin aldehyde............................. 34366 7421-93-4
Heptachlor.................................. 39410 76-44-8
Heptachlor epoxide.......................... 39420 1024-57-3
Toxaphene................................... 39400 8001-35-2
PCB-1016.................................... 34671 12674-11-2
PCB-1221.................................... 39488 1104-28-2
PCB-1232.................................... 39492 11141-16-5
PCB-1242.................................... 39496 53469-21-9
PCB-1248.................................... 39500 12672-29-6
PCB-1254.................................... 39504 11097-69-1
PCB-1260.................................... 39508 11096-82-5
------------------------------------------------------------------------

1.2 This is a gas chromatographic (GC) method applicable to the
determination of the compounds listed above in municipal and industrial
discharges as provided under 40 CFR 136.1. When this method is used to
analyze unfamiliar samples for any or all of the compounds above,
compound identifications should be supported by at least one additional
qualitative technique. This method describes analytical conditions for a
second gas chromatographic column that can be used to confirm
measurements made with the primary column. Method 625 provides gas
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the
qualitative and quantitative confirmation of results for all of the
parameters listed above, using the extract produced by this method.
1.3 The method detection limit (MDL, defined in Section 14.1)\1\ for
each parameter is listed in Table 1. The MDL for a specific wastewater
may differ from those listed, depending upon the nature of interferences
in the sample matrix.
1.4 The sample extraction and concentration steps in this method are
essentially the same as in Methods 606, 609, 611, and 612. Thus, a
single sample may be extracted to measure the parameters included in the
scope of each of these methods. When cleanup is required, the
concentration levels must be high enough to permit selecting aliquots,
as necessary, to apply appropriate cleanup procedures. The analyst is
allowed the latitude, under Section 12, to select chromatographic
conditions appropriate for the simultaneous measurement of combinations
of these parameters.
1.5 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.6 This method is restricted to use by or under the supervision of
analysts experienced in the use of a gas chromatograph and in the
interpretation of gas chromatograms. Each analyst must demonstrate the
ability to generate acceptable results with this method using the
procedure described in Section 8.2.

2. Summary of Method

2.1 A measured volume of sample, approximately 1-L, is extracted
with methylene chloride using a separatory funnel. The methylene
chloride extract is dried and exchanged to hexane during concentration
to a volume of 10 mL or less. The extract is separated by gas
chromatography and the parameters are then measured with an electron
capture detector.\2\
2.2 The method provides a Florisil column cleanup procedure and an
elemental sulfur removal procedure to aid in the elimination of
interferences that may be encountered.

3. Interferences

[[Page 120]]

3.1.2 The use of high purity reagents and solvents helps to minimize
interference problems. Purification of solvents by distillation in all-
glass systems may be required.
3.2 Interferences by phthalate esters can pose a major problem in
pesticide analysis when using the electron capture detector. These
compounds generally appear in the chromatogram as large late eluting
peaks, especially in the 15 and 50% fractions from Florisil. Common
flexible plastics contain varying amounts of phthalates. These
phthalates are easily extracted or leached from such materials during
laboratory operations. Cross contamination of clean glassware routinely
occurs when plastics are handled during extraction steps, especially
when solvent-wetted surfaces are handled. Interferences from phthalates
can best be minimized by avoiding the use of plastics in the laboratory.
Exhaustive cleanup of reagents and glassware may be required to
eliminate background phthalate contamination.^{4, 5} The
interferences from phthalate esters can be avoided by using a
microcoulometric or electrolytic conductivity detector.
3.3 Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary
considerably from source to source, depending upon the nature and
diversity of the industrial complex or municipality being sampled. The
cleanup procedures in Section 11 can be used to overcome many of these
interferences, but unique samples may require additional cleanup
approaches to achieve the MDL listed in Table 1.

4. Safety

4.1 The toxicity or carcinogenicity of each reagent used in this
method has not been precisely defined; however, each chemical compound
should be treated as a potential health hazard. From this viewpoint,
exposure to these chemicals must be reduced to the lowest possible level
by whatever means available. The laboratory is responsible for
maintaining a current awareness file of OSHA regulations regarding the
safe handling of the chemicals specified in this method. A reference
file of material data handling sheets should also be made available to
all personnel involved in the chemical analysis. Additional references
to laboratory safety are available and have been identified
^6-8 for the information of the analyst.
4.2 The following parameters covered by this method have been
tentatively classified as known or suspected, human or mammalian
carcinogens: 4,4'-DDT, 4,4'-DDD, the BHCs, and the PCBs. Primary
standards of these toxic compounds should be prepared in a hood. A
NIOSH/MESA approved toxic gas respirator should be worn when the analyst
handles high concentrations of these toxic compounds.

5. Apparatus and Materials

[[Page 121]]

chart recorder. A data system is recommended for measuring peak areas.
5.6.1 Column 1--1.8 m long x 4 mm ID glass, packed with 1.5% SP-
2250/1.95% SP-2401 on Supelcoport (100/120 mesh) or equivalent. This
column was used to develop the method performance statements in Section
14. Guidelines for the use of alternate column packings are provided in
Section 12.1.
5.6.2 Column 2--1.8 m long x 4 mm ID glass, packed with 3% OV-1 on
Supelcoport (100/120 mesh) or equivalent.
5.6.3 Detector--Electron capture detector. This detector has proven
effective in the analysis of wastewaters for the parameters listed in
the scope (Section 1.1), and was used to develop the method performance
statements in Section 14. Guidelines for the use of alternate detectors
are provided in Section 12.1.

6. Reagents

6.1 Reagent water--Reagent water is defined as a water in which an
interferent is not observed at the MDL of the parameters of interest.
6.2 Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) in
reagent water and dilute to 100 mL.
6.3 Sodium thiosulfate--(ACS) Granular.
6.4 Sulfuric acid (1+1)--Slowly, add 50 mL to
H2SO4 (ACS, sp. gr. 1.84) to 50 mL of reagent
water.
6.5 Acetone, hexane, isooctane, methylene chloride--Pesticide
quality or equivalent.
6.6 Ethyl ether--Nanograde, redistilled in glass if necessary.
6.6.1 Ethyl ether must be shown to be free of peroxides before it is
used as indicated by EM Laboratories Quant test strips. (Available from
Scientific Products Co., Cat. No. P1126-8, and other suppliers.)
6.6.2 Procedures recommended for removal of peroxides are provided
with the test strips. After cleanup, 20 mL of ethyl alcohol preservative
must be added to each liter of ether.
6.7 Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at
400 [deg]C for 4 h in a shallow tray.
6.8 Florisil--PR grade (60/100 mesh). Purchase activated at 1250
[deg]F and store in the dark in glass containers with ground glass
stoppers or foil-lined screw caps. Before use, activate each batch at
least 16 h at 130 [deg]C in a foil-covered glass container and allow to
cool.
6.9 Mercury--Triple distilled.
6.10 Copper powder--Activated.
6.11 Stock standard solutions (1.00 [mu]g/[mu]L)--Stock standard
solutions can be prepared from pure standard materials or purchased as
certified solutions.
6.11.1 Prepare stock standard solutions by accurately weighing about
0.0100 g of pure material. Dissolve the material in isooctane and dilute
to volume in a 10-mL volumetric flask. Larger volumes can be used at the
convenience of the analyst. When compound purity is assayed to be 96% or
greater, the weight can be used without correction to calculate the
concentration of the stock standard. Commercially prepared stock
standards can be used at any concentration if they are certified by the
manufacturer or by an independent source.
6.11.2 Transfer the stock standard solutions into Teflon-sealed
screw-cap bottles. Store at 4 [deg]C and protect from light. Stock
standard solutions should be checked frequently for signs of degradation
or evaporation, especially just prior to preparing calibration standards
from them.
6.11.3 Stock standard solutions must be replaced after six months,
or sooner if comparison with check standards indicates a problem.
6.12 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

[[Page 122]]

be suggested that is applicable to all samples.
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask. To each calibration
standard, add a known constant amount of one or more internal standards,
and dilute to volume with isooctane. One of the standards should be at a
concentration near, but above, the MDL and the other concentrations
should correspond to the expected range of concentrations found in real
samples or should define the working range of the detector.
7.3.2 Using injections of 2 to 5 [mu]L, analyze each calibration
standard according to Section 12 and tabulate peak height or area
responses against concentration for each compound and internal standard.
Calculate response factors (RF) for each compound using Equation 1.
[GRAPHIC] [TIFF OMITTED] TC15NO91.107

Equation 1
where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Cis=Concentration of the internal standard ([mu]g/L).
Cs=Concentraton of the parameter to be measured ([mu]g/L).

If the RF value over the working range is a constant (<10% RSD), the
RF can be assumed to be invariant and the average RF can be used for
calculations. Alternatively, the results can be used to plot a
calibration curve of response ratios, As/Ais, vs.
RF.
7.4 The working calibration curve, calibration factor, or RF must be
verified on each working day by the measurement of one or more
calibration standards. If the response for any parameter varies from the
predicted response by more than +-15%, the test must be repeated using a
fresh calibration standard. Alternatively, a new calibration curve must
be prepared for that compound.
7.5 The cleanup procedure in Section 11 utilizes Florisil column
chromatography. Florisil from different batches or sources may vary in
adsorptive capacity. To standardize the amount of Florisil which is
used, the use of lauric acid value \9\ is suggested. The referenced
procedure determines the adsorption from hexane solution of lauric acid
(mg) per g of Florisil. The amount of Florisil to be used for each
column is calculated by dividing 110 by this ratio and multiplying by 20
g.
7.6 Before using any cleanup procedure, the analyst must process a
series of calibration standards through the procedure to validate
elution patterns and the absence of interferences from the reagents.

8. Quality Control

[[Page 123]]

8.2.1 A quality control (QC) check sample concentrate is required
containing each single-component parameter of interest at the following
concentrations in acetone: 4,4'-DDD, 10 [mu]g/mL; 4,4'-DDT, 10 [mu]g/mL;
endosulfan II, 10 [mu]g/mL; endosulfan sulfate, 10 [mu]g/mL; endrin, 10
[mu]g/mL; any other single-component pesticide, 2 [mu]g/mL. If this
method is only to be used to analyze for PCBs, chlordane, or toxaphene,
the QC check sample concentrate should contain the most representative
multicomponent parameter at a concentration of 50 [mu]g/mL in acetone.
The QC check sample concentrate must be obtained from the U.S.
Environmental Protection Agency, Environmental Monitoring and Support
Laboratory in Cincinnati, Ohio, if available. If not available from that
source, the QC check sample concentrate must be obtained from another
external source. If not available from either source above, the QC check
sample concentrate must be prepared by the laboratory using stock
standards prepared independently from those used for calibration.
8.2.2 Using a pipet, prepare QC check samples at the test
concentrations shown in Table 3 by adding 1.00 mL of QC check sample
concentrate to each of four 1-L aliquots of reagent water.
8.2.3 Analyze the well-mixed QC check samples according to the
method beginning in Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/mL; and the
standard deviation of the recovery (s) in [mu]g/mL, for each parameter
using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively, found in
Table 3. If s and X for all parameters of interest meet the acceptance
criteria, the system performance is acceptable and analysis of actual
samples can begin. If any individual s exceeds the precision limit or
any individual X falls outside the range for accuracy, the system
performance is unacceptable for that parameter.
Note: The large number of parameters in Table 3 present a
substantial probability that one or more will fail at least one of the
acceptance criteria when all parameters are analyzed.
8.2.6 When one or more of the parameters tested fail at least one of
the acceptance criteria, the analyst must proceed according to Section
8.2.6.1 or 8.2.6.2.
8.2.6.1 Locate and correct the source of the problem and repeat the
test for all parameters of interest beginning with Section 8.2.2.
8.2.6.2 Beginning with Section 8.2.2, repeat the test only for those
parameters that failed to meet criteria. Repeated failure, however, will
confirm a general problem with the measurement system. If this occurs,
locate and correct the source of the problem and repeat the test for all
compmunds of interest beginning with Section 8.2.2.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at the test concentration in Section 8.2.2 or 1 to 5
times higher than the background concentration determined in Section
8.3.2, whichever concentration would be larger.
8.3.1.3 If it is impractical to determine background levels before
spiking (e.g., maximum holding times will be exceeded), the spike
concentration should be (1) the regulatory concentration limit, if any;
or, if none (2) the larger of either 5 times higher than the expected
background concentration or the test concentration in Section 8.2.2.
8.3.2 Analyze one sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second sample aliquot with 1.0 mL
of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100(A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 3. These acceptance
criteria were calculated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.\10\ If spiking was performed at a concentration lower than the test
concentration in Section 8.2.2, the analyst must use either the QC
acceptance criteria in Table 3, or optional QC acceptance criteria
calculated for the specific spike concentration. To calculate optional
acceptance criteria for the recovery of a parameter: (1) Calculate
accuracy (X') using the equation in Table 4, substituting the spike
concentration (T) for C; (2) calculate overall precision (S') using the
equation in Table 4, substituting X'

[[Page 124]]

for X; (3) calculate the range for recovery at the spike concentration
as (100 X'/T)+-2.44(100 S'/T)%.\10\
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory. If the entire list of parameters in Table 3 must be measured
in the sample in Section 8.3, the probability that the analysis of a QC
check standard will be required is high. In this case the QC check
standard should be routinely analyzed with the spike sample.
8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The
QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standards to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
3. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2 sp to P+2 sp.
If P=90% and sp=10%, for example, the accuracy interval is
expressed as 70-110%. Update the accuracy assessment for each parameter
on a regular basis (e.g. after each five to ten new accuracy
measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates may be analyzed to assess the
precision of the environmental measurements. When doubt exists over the
identification of a peak on the chromatogram, confirmatory techniques
such as gas chromatography with a dissimilar column, specific element
detector, or mass spectrometer must be used. Whenever possible, the
laboratory should analyze standard reference materials and participate
in relevant performance evaluation studies.

9. Sample Collection, Preservation, and Handling

9.1 Grab samples must be collected in glass containers. Conventional
sampling practices \11\ should be followed, except that the bottle must
not be prerinsed with sample before collection. Composite samples should
be collected in refrigerated glass containers in accordance with the
requirements of the program. Automatic sampling equipment must be as
free as possible of Tygon tubing and other potential sources of
contamination.
9.2 All samples must be iced or refrigerated at 4 [deg]C from the
time of collection until extraction. If the samples will not be
extracted within 72 h of collection, the sample should be adjusted to a
pH range of 5.0 to 9.0 with sodium hydroxide solution or sulfuric acid.
Record the volume of acid or base used. If aldrin is to be determined,
add sodium thiosulfate when residual chlorine is present. EPA Methods
330.4 and 330.5 may be used for measurement of residual chlorine.\12\
Field test kits are available for this purpose.
9.3 All samples must be extracted within 7 days of collection and
completely analyzed within 40 days of extraction.\2\

10. Sample Extraction

[[Page 125]]

10.3 Add a second 60-mL volume of methylene chloride to the sample
bottle and repeat the extraction procedure a second time, combining the
extracts in the Erlenmeyer flask. Perform a third extraction in the same
manner.
10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-
mL concentrator tube to a 500-mL evaporative flask. Other concentration
devices or techniques may be used in place of the K-D concentrator if
the requirements of Section 8.2 are met.
10.5 Pour the combined extract through a solvent-rinsed drying
column containing about 10 cm of anhydrous sodium sulfate, and collect
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and
column with 20 to 30 mL of methylene chloride to complete the
quantitative transfer.
10.6 Add one or two clean boiling chips to the evaporative flask and
attach a three-ball Snyder column. Prewet the Snyder column by adding
about 1 mL of methylene chloride to the top. Place the K-D apparatus on
a hot water bath (60 to 65 [deg]C) so that the concentrator tube is
partially immersed in the hot water, and the entire lower rounded
surface of the flask is bathed with hot vapor. Adjust the vertical
position of the apparatus and the water temperature as required to
complete the concentration in 15 to 20 min. At the proper rate of
distillation the balls of the column will actively chatter but the
chambers will not flood with condensed solvent. When the apparent volume
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain
and cool for at least 10 min.
10.7 Increase the temperature of the hot water bath to about 80
[deg]C. Momeltarily remove the Snyder column, add 50 mL of hexane and a
new boiling chip, and reattach the Snyder column. Concentrate the
extract as in Section 10.6, except use hexane to prewet the column. The
elapsed time of concentration should be 5 to 10 min.
10.8 Remove the Snyder column and rinse the flask and its lower
joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL
syringe is recommended for this operation. Stopper the concentrator tube
and store refrigerated if further processing will not be performed
immediately. If the extract will be stored longer than two days, it
should be transferred to a Teflon-sealed screw-cap vial. If the sample
extract requires no further cleanup, proceed with gas
chroma[chyph]tographic analysis (Section 12). If the sample
[chyph]requires further cleanup, proceed to Sec[chyph]tion 11.
10.9 Determine the original sample volume by refilling the sample
bottle to the mark and transferring the liquid to a 1000-mL graduated
cylinder. Record the sample volume to the nearest 5 mL.

11. Cleanup and Separation

[[Page 126]]

seal.\13\ Agitate the contents of the vial for 15 to 30 s. Prolonged
shaking (2 h) may be required. If so, this may be accomplished with a
reciprocal shaker. Alternatively, activated copper powder may be used
for sulfur removal.\14\ Analyze by gas chromatography.

12. Gas Chromatography

12.1 Table 1 summarizes the recommended operating conditions for the
gas chromatograph. Included in this table are retention times and MDL
that can be achieved under these conditions. Examples of the separations
achieved by Column 1 are shown in Figures 1 to 10. Other packed or
capillary (open-tubular) columns, chromatographic conditions, or
detectors may be used if the requirements of Section 8.2 are met.
12.2 Calibrate the system daily as described in Section 7.
12.3 If the internal standard calibration procedure is being used,
the internal standard must be added to the sample extract and mixed
thoroughly immediately before injection into the gas chromatograph.
12.4 Inject 2 to 5 [mu]L of the sample extract or standard into the
gas chromatograph using the solvent-flush technique.\15\ Smaller (1.0
uL) volumes may be injected if automatic devices are employed. Record
the volume injected to the nearest 0.05 [mu]L, the total extract volume,
and the resulting peak size in area or peak height units.
12.5 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
can be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.
12.6 If the response for a peak exceeds the working range of the
system, dilute the extract and reanalyze.
12.7 If the measurement of the peak response is prevented by the
presence of interferences, further cleanup is required.

13. Calculations

Equation 2

where:
A=Amount of material injected (ng).
Vi=Volume of extract injected ([mu]L).
Vt=Volume of total extract ([mu]L).
Vs=Volume of water extracted (mL).

Equation 3

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Is=Amount of internal standard added to each extract ([mu]g).
Vo=Volume of water extracted (L).

13.2 When it is apparent that two or more PCB (Aroclor) mixtures are
present, the Webb and McCall procedure \16\ may be used to identify and
quantify the Aroclors.
13.3 For multicomponent mixtures (chlordane, toxaphene, and PCBs)
match retention times of peaks in the standards with peaks in the
sample. Quantitate every identifiable peak unless interference with
individual peaks persist after cleanup. Add peak height or peak area of
each identified peak in the chromatogram. Calculate as total response in
the sample versus total response in the standard.
13.4 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

14. Method Performance

[[Page 127]]

Toxaphene recovery was demonstrated linear over the range of 10xMDL to
1000xMDL.\17\
14.3 This method was tested by 20 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
at six concentrations.\18\ Concentrations used in the study ranged from
0.5 to 30 [mu]g/L for single-component pesticides and from 8.5 to 400
[mu]g/L for multicomponent parameters. Single operator precision,
overall precision, and method accuracy were found to be directly related
to the concentration of the parameter and essentially independent of the
sample matrix. Linear equations to describe these relationships are
presented in Table 4.

References

1. 40 CFR part 136, appendix B.
2. ``Determination of Pesticides and PCBs in Industrial and
Municipal Wastewaters,'' EPA 600/4-82-023, National Technical
Information Service, PB82-214222, Springfield, Virginia 22161, April
1982.
3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard
Practices for Preparation of Sample Containers and for Preservation of
Organic Constituents,'' American Society for Testing and Materials,
Philadelphia.
4. Giam, C.S., Chan, H.S., and Nef, G.S., ``Sensitive Method for
Determination of Phthalate Ester Plasticizers in Open-Ocean Biota
Samples,'' Analytical Chemistry, 47, 2225 (1975).
5. Giam, C.S., Chan, H.S. ``Control of Blanks in the Analysis of
Phthalates in Air and Ocean Biota Samples,'' U.S. National Bureau of
Standards, Special Publication 442, pp. 701-708, 1976.
6. ``Carcinogens--Working With Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
7. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
8. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
9. Mills, P.A. ``Variation of Florisil Activity: Simple Method for
Measuring Absorbent Capacity and Its Use in Standardizing Florisil
Columns,'' Journal of the Association of Official Analytical Chemists,
51, 29, (1968).
10. Provost, L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3 is two times the value 1.22
derived in this report.)
11. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard
Practices for Sampling Water,'' American Society for Testing and
Materials, Philadelphia.
12. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S.
Environmental Protection Agency, Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio 45268, March 1979.
13. Goerlitz, D.F., and Law, L.M. Bulletin for Environmental
Contamination and Toxicology, 6, 9 (1971).
14. ``Manual of Analytical Methods for the Analysis of Pesticides in
Human and Environmental Samples,'' EPA-600/8-80-038, U.S. Environmental
Protection Agency, Health Effects Research Laboratory, Research Triangle
Park, North Carolina.
15. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis;
Some Practical Aspects,'' Journal of the Association of Official
Analytical Chemists, 48, 1037 (1965).
16. Webb, R.G., and McCall, A.C. ``Quantitative PCB Standards for
Election Capture Gas Chromatography,'' Journal of Chromatographic
Science, 11, 366 (1973).
17. ``Method Detection Limit and Analytical Curve Studies, EPA
Methods 606, 607, and 608,'' Special letter report for EPA Contract 68-
03-2606, U.S. Environmental Protection Agency, Environmental Monitoring
and Support Laboratory, Cincinnati, Ohio 45268, June 1980.
18. ``EPA Method Study 18 Method 608--Organochlorine Pesticides and
PCBs,'' EPA 600/4-84-061, National Technical Information Service, PB84-
211358, Springfield, Virginia 22161, June 1984.

[[Page 128]]

4,4'-DDE....................... 5.13 7.15 0.004
Dieldrin....................... 5.45 7.23 0.002
Endrin......................... 6.55 8.10 0.006
4,4'-DDD....................... 7.83 9.08 0.011
Endosulfan II.................. 8.00 8.28 0.004
4,4'-DDT....................... 9.40 11.75 0.012
Endrin aldehyde................ 11.82 9.30 0.023
Endosulfan sulfate............. 14.22 10.70 0.066
Chlordane...................... mr mr 0.014
Toxaphene...................... mr mr 0.24
PCB-1016....................... mr mr nd
PCB-1221....................... mr mr nd
PCB-1232....................... mt mr nd
PCB-1242....................... mr mr 0.065
PCB-1248....................... mr mr nd
PCB-1254....................... mr mr nd
PCB-1260....................... mr mr nd
------------------------------------------------------------------------
AColumn 1 conditions: Supelcoport (100/120 mesh) coated with 1.5% SP-
2250/1.95% SP-2401 packed in a 1.8 m long x 4 mm ID glass column with
5% methane/95% argon carrier gas at 60 mL/min flow rate. Column
temperature held isothermal at 200 [deg]C, except for PCB-1016 through
PCB-1248, should be measured at 160 [deg]C.
AColumn 2 conditions: Supelcoport (100/120 mesh) coated with 3% OV-1
packed in a 1.8 m long x 4 mm ID glass column with 5% methane/95%
argon carrier gas at 60 mL/min flow rate. Column temperature held
isothermal at 200 [deg]C for the pesticides; at 140 [deg]C for PCB-
1221 and 1232; and at 170 [deg]C for PCB-1016 and 1242 to 1268.
Amr=Multiple peak response. See Figures 2 thru 10.
And=Not determined.

Table 2--Distribution of Chlorinated Pesticides and PCBs into Florisil
Column Fractions 2
------------------------------------------------------------------------
Percent recovery by fraction \a\
Parameter --------------------------------------
1 2 3
------------------------------------------------------------------------
Aldrin........................... 100 ........... ...........
[alpha]-BHC...................... 100 ........... ...........
[beta]-BHC....................... 97 ........... ...........
[delta]-BHC...................... 98 ........... ...........
[gamma]-BHC...................... 100 ........... ...........
Chlordane........................ 100 ........... ...........
4,4'-DDD......................... 99 ........... ...........
4,4'-DDE......................... 98 ........... ...........
4,4'-DDT......................... 100 ........... ...........
Dieldrin......................... 0 100 ...........
Endosulfan I..................... 37 64 ...........
Endosulfan II.................... 0 7 91
Endosulfan sulfate............... 0 0 106
Endrin........................... 4 96 ...........
Endrin aldehyde.................. 0 68 26
Heptachlor....................... 100 ........... ...........
Heptachlor epoxide............... 100 ........... ...........
Toxaphene........................ 96 ........... ...........
PCB-1016......................... 97 ........... ...........
PCB-1221......................... 97 ........... ...........
PCB-1232......................... 95 4 ...........
PCB-1242......................... 97 ........... ...........
PCB-1248......................... 103 ........... ...........
PCB-1254......................... 90 ........... ...........
PCB-1260......................... 95 ........... ...........
------------------------------------------------------------------------
\a\ Eluant composition:
Fraction 1-6% ethyl ether in hexane.
Fraction 2-15% ethyl ether in hexane.
Fraction 3-50% ethyl ether in hexane.

Table 3--QC Acceptance Criteria--Method 608
----------------------------------------------------------------------------------------------------------------
Range for
Parameter Test conc. Limit for s X ([mu]g/ Range for
([mu]g/L) ([mu]g/L) L) P, Ps(%)
----------------------------------------------------------------------------------------------------------------
Aldrin...................................................... 2.0 0.42 1.08-2.24 42-122
[alpha]-BHC................................................. 2.0 0.48 0.98-2.44 37-134

[[Page 129]]

[beta]-BHC.................................................. 2.0 0.64 0.78-2.60 17-147
[delta]-BHC................................................. 2.0 0.72 1.01-2.37 19-140
[gamma]-BHC................................................. 2.0 0.46 0.86-2.32 32-127
Chlordane................................................... 50 10.0 27.6-54.3 45-119
4,4 '-DDD................................................... 10 2.8 4.8-12.6 31-141
4,4 '-DDE................................................... 2.0 0.55 1.08-2.60 30-145
4,4'-DDT.................................................... 10 3.6 4.6-13.7 25-160
Dieldrin.................................................... 2.0 0.76 1.15-2.49 36-146
Endosulfan I................................................ 2.0 0.49 1.14-2.82 45-153
Endosulfan II............................................... 10 6.1 2.2-17.1 D-202
Endosulfan Sulfate.......................................... 10 2.7 3.8-13.2 26-144
Endrin...................................................... 10 3.7 5.1-12.6 30-147
Heptachlor.................................................. 2.0 0.40 0.86-2.00 34-111
Heptachlor epoxide.......................................... 2.0 0.41 1.13-2.63 37-142
Toxaphene................................................... 50.0 12.7 27.8-55.6 41-126
PCB-1016.................................................... 50 10.0 30.5-51.5 50-114
PCB-1221.................................................... 50 24.4 22.1-75.2 15-178
PCB-1232.................................................... 50 17.9 14.0-98.5 10-215
PCB-1242.................................................... 50 12.2 24.8-69.6 39-150
PCB-1248.................................................... 50 15.9 29.0-70.2 38-158
PCB-1254.................................................... 50 13.8 22.2-57.9 29-131
PCB-1260.................................................... 50 10.4 18.7-54.9 8-127
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).
D=Detected; result must be greater than zero.

Table 4--Method Accuracy and Precision as Functions of Concentration--Method 608
----------------------------------------------------------------------------------------------------------------
Accuracy, as Single analyst
Parameter recovery, X' precision, sr' Overall precision,
([mu]g/L) ([mu]g/L) S' ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
Aldrin.............................................. 0.81C+0.04 0.16X-0.04 0.20X-0.01
[alpha]-BHC......................................... 0.84C+0.03 0.13X+0.04 0.23X-0.00
[beta]-BHC.......................................... 0.81C+0.07 0.22X-0.02 0.33X-0.05
[delta]-BHC......................................... 0.81C+0.07 0.18X+0.09 0.25X+0.03
[gamma]-BHC......................................... 0.82C-0.05 0.12X+0.06 0.22X+0.04
Chlordane........................................... 0.82C-0.04 0.13X+0.13 0.18X+0.18
4,4'-DDD............................................ 0.84C+0.30 0.20X-0.18 0.27X-0.14
4,4'-DDE............................................ 0.85C+0.14 0.13X+0.06 0.28X-0.09
4,4'-DDT............................................ 0.93C-0.13 0.17X+0.39 0.31X-0.21
Dieldrin............................................ 0.90C+0.02 0.12X+0.19 0.16X+0.16
Endosulfan I........................................ 0.97C+0.04 0.10X+0.07 0.18X+0.08
Endosulfan II....................................... 0.93C+0.34 0.41X--0.65 0.47X-0.20
Endosulfan Sulfate.................................. 0.89C-0.37 0.13X+0.33 0.24X+0.35
Endrin.............................................. 0.89C-0.04 0.20X+0.25 0.24X+0.25
Heptachlor.......................................... 0.69C+0.04 0.06X+0.13 0.16X+0.08
Heptachlor epoxide.................................. 0.89C+0.10 0.18X-0.11 0.25X-0.08
Toxaphene........................................... 0.80C+1.74 0.09X+3.20 0.20X+0.22
PCB-1016............................................ 0.81C+0.50 0.13X+0.15 0.15X+0.45
PCB-1221............................................ 0.96C+0.65 0.29X-0.76 0.35X-0.62
PCB-1232............................................ 0.91C+10.79 0.21X-1.93 0.31X+3.50
PCB-1242............................................ 0.93C+0.70 0.11X+1.40 0.21X+1.52
PCB-1248............................................ 0.97C+1.06 0.17X+0.41 0.25X-0.37
PCB-1254............................................ 0.76C+2.07 0.15X+1.66 0.17X+3.62
PCB-1260............................................ 0.66C+3.76 0.22X-2.37 0.39X-4.86
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
sr'=Expected single analyst standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
C=True value for the concentration, in [mu]g/L.
X=Average recovery found for measurements of samples containing a concentration of C, in [mu]g/L.

[[Page 130]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.019

[[Page 131]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.020

[[Page 132]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.021

[[Page 133]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.022

[GRAPHIC] [TIFF OMITTED] TC02JY92.023

[[Page 135]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.024

[[Page 136]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.025

[[Page 137]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.026

[[Page 138]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.027

[[Page 139]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.028

Method 609--Nitroaromatics and Isophorone

1. Scope and Application

1.1 This method covers the determination of certain nitroaromatics
and isophorone. The following parameters may be determined by this
method:

1.2 This is a gas chromatographic (GC) method applicable to the
determination of

[[Page 140]]

the compounds listed above in municipal and industrial discharges as
provided under 40 CFR 136.1. When this method is used to analyze
unfamiliar samples for any or all of the compounds above, compound
identifications should be supported by at least one additional
qualitative technique. This method describes analytical conditions for a
second gas chromatographic column that can be used to confirm
measurements made with the primary column. Method 625 provides gas
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the
qualitative and quantitative confirmation of results for all of the
parameters listed above, using the extract produced by this method.
1.3 The method detection limit (MDL, defined in Section 14.1)\1\ for
each parameter is listed in Table 1. The MDL for a specific wastewater
may differ from those listed, depending upon the nature of interferences
in the sample matrix.
1.4 The sample extraction and concentration steps in this method are
essentially the same as in Methods 606, 608, 611, and 612. Thus, a
single sample may be extracted to measure the parameters included in the
scope of each of these methods. When cleanup is required, the
concentration levels must be high enough to permit selecting aliquots,
as necessary, to apply appropriate cleanup procedures. The analyst is
allowed the latitude, under Section 12, to select chromatographic
conditions appropriate for the simultaneous measurement of combinations
of these parameters.
1.5 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.6 This method is restricted to use by or under the supervision of
analysts experienced in the use of a gas chromatograph and in the
interpretation of gas chromatograms. Each analyst must demonstrate the
ability to generate acceptable results with this method using the
procedure described in Section 8.2.

2. Summary of Method

2.1 A measured volume of sample, approximately 1-L, is extracted
with methylene chloride using a separatory funnel. The methylene
chloride extract is dried and exchanged to hexane during concentration
to a volume of 10 mL or less. Isophorone and nitrobenzene are measured
by flame ionization detector gas chromatography (FIDGC). The
dinitrotoluenes are measured by electron capture detector gas
chromatography (ECDGC).\2\
2.2 The method provides a Florisil column cleanup procedure to aid
in the elimination of interferences that may be encountered.

3. Interferences

3.1 Method interferences may be caused by contaminants in solvents,
reagents, glassware, and other sample processing hardware that lead to
discrete artifacts and/or elevated baseliles in gas chromatograms. All
of these materials must be routinely demonstrated to be free from
interferences under the conditions of the analysis by running laboratory
reagent blanks as described in Section 8.1.3.
3.1.1 Glassware must be scrupulously cleaned.\3\ Clean all glassware
as soon as possible after use by rinsing with the last solvent used in
it. Solvent rinsing should be followed by detergent washing with hot
water, and rinses with tap water and distilled water. The glassware
should then be drained dry, and heated in a muffle furnace at 400 [deg]C
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not
be eliminated by this treatment. Solvent rinses with acetone and
pesticide quality hexane may be substituted for the muffle furnace
heating. Thorough rinsing with such solvents usually eliminates PCB
interference. Volumetric ware should not be heated in a muffle furnace.
After drying and cooling, glassware should be sealed and stored in a
clean environment to prevent any accumulation of dust or other
contaminants. Store inverted or capped with aluminum foil.
3.1.2 The use of high purity reagents and solvents helps to minimize
interference problems. Purification of solvents by distillation in all-
glass systems may be required.
3.2 Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary
considerably from source to source, depending upon the nature and
diversity of the industrial complex or municipality being sampled. The
cleanup procedure in Section 11 can be used to overcome many of these
interferences, but unique samples may require additional cleanup
approaches to achieve the MDL listed in Table 1.

4. Safety

[[Page 141]]

5. Apparatus and Materials

5.1 Sampling equipment, for discrete or composite sampling.
5.1.1 Grab sample bottle--1-L or 1-qt, amber glass, fitted with a
screw cap lined with Teflon. Foil may be substituted for Teflon if the
sample is not corrosive. If amber bottles are not available, protect
samples from light. The bottle and cap liner must be washed, rinsed with
acetone or methylene chloride, and dried before use to minimize
contamination.
5.1.2 Automatic sampler (optional)--The sampler must incorporate
glass sample containers for the collection of a minimum of 250 mL of
sample. Sample containers must be kept refrigerated at 4 [deg]C and
protected from light during compositing. If the sampler uses a
peristaltic pump, a minimum length of compressible silicone rubber
tubing may be used. Before use, however, the compressible tubing should
be thoroughly rinsed with methanol, followed by repeated rinsings with
distilled water to minimize the potential for contamination of the
sample. An integrating flow meter is required to collect flow
proportional composites.
5.2 Glassware (All specifications are suggested. Catalog numbers are
included for illustration only.):
5.2.1 Separatory funnel--2-L, with Teflon stopcock.
5.2.2 Drying column--Chromatographic column, approximately 400 mm
long x 19 mm ID, with coarse frit filter disc.
5.2.3 Chromatographic column--100 mm long x 10 mm ID, with Teflon
stopcock.
5.2.4 Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes K-
570050-1025 or equivalent). Calibration must be checked at the volumes
employed in the test. Ground glass stopper is used to prevent
evaporation of extracts.
5.2.5 Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
5.2.6 Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
5.2.7 Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
5.2.8 Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
5.3 Boiling chips--Approximately 10/40 mesh. Heat to 400 [deg]C for
30 min or Soxhlet extract with methylene chloride.
5.4 Water bath--Heated, with concentric ring cover, capable of
temperature control (+-2 [deg]C). The bath should be used in a hood.
5.5 Balance--Analytical, capable of accurately weighing 0.0001 g.
5.6 Gas chromatograph--An analytical system complete with gas
chromatograph suitable for on-column injection and all required
accessories including syringes, analytical columns, gases, detector, and
strip-chart recorder. A data system is recommended for measuring peak
areas.
5.6.1 Column 1--1.2 m long x 2 or 4 mm ID glass, packed with 1.95%
QF-1/1.5% OV-17 on Gas-Chrom Q (80/100 mesh) or equivalent. This column
was used to develop the method performance statements given in Section
14. Guidelines for the use of alternate column packings are provided in
Section 12.1.
5.6.2 Column 2--3.0 m long x 2 or 4 mm ID glass, packed with 3% OV-
101 on Gas-Chrom Q (80/100 mesh) or equivalent.
5.6.3 Detectors--Flame ionization and electron capture detectors.
The flame ionization detector (FID) is used when determining isophorone
and nitrobenzene. The electron capture detector (ECD) is used when
determining the dinitrotoluenes. Both detectors have proven effective in
the analysis of wastewaters and were used in develop the method
performance statements in Section 14. Guidelines for the use to
alternate detectors are provided in Section 12.1.

6. Reagents

[[Page 142]]

Store at 4 [deg]C and protect from light. Stock standard solutions
should be checked frequently for signs of degradation or evaporation,
especially just prior to preparing calibration standards from them.
6.7.3 Stock standard solutions must be replaced after six months, or
sooner if comparison with check standards indicates a problem.
6.8 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

7.1 Establish gas chromatographic operating conditions equivalent to
those given in Table 1. The gas chromatographic system can be calibrated
using the external standard technique (Section 7.2) or the internal
standard technique (Section 7.3).
7.2 External standard calibration procedure:
7.2.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask and diluting to volume
with hexane. One of the external standards should be at a concentration
near, but above, the MDL (Table 1) and the other concentrations should
correspond to the expected range of concentrations found in real samples
or should define the working range of the detector.
7.2.2 Using injections of 2 to 5 [mu]L, analyze each calibration
standard according to Section 12 and tabulate peak height or area
responses against the mass injected. The results can be used to prepare
a calibration curve for each compound. Alternatively, if the ratio of
response to amount injected (calibration factor) is a constant over the
working range (<10% relative standard deviation, RSD) linearity through
the origin can be assumed and the average ratio or calibration factor
can be used in place of a calibration curve.
7.3 Internal standard calibration procedure--To use this approach,
the analyst must select one or more internal standards that are similar
in analytical behavior to the compounds of interest. The analyst must
further demonstrate that the measurement of the internal standard is not
affected by method or matrix interferences. Because of these
limitations, no internal standard can be suggested that is applicable to
all samples.
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flash. To each calibration
standard, add a known constant amount of one or more internal standards,
and dilute to volume with hexane. One of the standards should be at a
concentration near, but above, the MDL and the other concentrations
should correspond to the expected range of concentrations found in real
samples or should define the working range of the detector.
7.3.2 Using injections of 2 to 5 [mu]L, analyze each calibration
standard according to Section 12 and tabulate peak height or area
responses against concentration for each compound and internal standard.
Calculate response factors (RF) for each compound using Equation 1.
Equation 1.
[GRAPHIC] [TIFF OMITTED] TC15NO91.110

8. Quality Control

[[Page 143]]

generate acceptable accuracy and precision with this method. This
ability is established as described in Section 8.2.
8.1.2 In recognition of advances that are occurring in
chromatography, the analyst is permitted certain options (detailed in
Sections 10.4, 11.1, and 12.1) to improve the separations or lower the
cost of measurements. Each time such a modification is made to the
method, the analyst is required to repeat the procedure in Section 8.2.
8.1.3 Before processing any samples, the analyst must analyze a
reagent water blank to demonstrate that interferences from the
analytical system and glassware are under control. Each time a set of
samples is extracted or reagents are changed, a reagent water blank must
be processed as a safeguard against laboratory contamination.
8.1.4 The laboratory must, on an ongoing basis, spike and analyze a
minimum of 10% of all samples to monitor and evaluate laboratory data
quality. This procedure is described in Section 8.3.
8.1,5 The laboratory must, on an ongoing basis, demonstrate through
the analyses of quality control check standards that the operation of
the measurement system is in control. This procedure is described in
Section 8.4. The frequency of the check standard analyses is equivalent
to 10% of all samples analyzed but may be reduced if spike recoveries
from samples (Section 8.3) meet all specified quality control criteria.
8.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is described in
Section 8.5.
8.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
8.2.1 A quality control (QC) check sample concentrate is required
containing each parameter of interest in acetone at a concentration of
20 [mu]g/mL for each dinitrotoluene and 100 [mu]g/mL for isophorone and
nitrobenzene. The QC check sample concentrate must be obtained from the
U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory in Cincinnati, Ohio, if available. If not available
from that source, the QC check sample concentrate must be obtained from
another external source. If not available from either source above, the
QC check sample concentrate must be prepared by the laboratory using
stock standards prepared independently from those used for calibration.
8.2.2 Using a pipet, prepare QC check samples at the test
concentrations shown in Table 2 by adding 1.00 mL of QC check sample
concentrate to each of four 1-L aliquots of reagent water.
8.2.3 Analyze the well-mixed QC check samples according to the
method beginning in Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter
using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively, found in
Table 2. If s and X for all parameters of interest meet the acceptance
criteria, the system performance is acceptable and analysis of actual
samples can begin. If any individual s exceeds the precision limit or
any individual X falls outside the range for accuracy, the system
performance is unacceptable for that parameter. Locate and correct the
source of the problem and repeat the test for all parameters of interest
beginning with Section 8.2.2.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at the test concentration in Section 8.2.2 or 1 to 5
times higher than the background concentration determined in Section
8.3.2, whichever concentration would be larger.
8.3.1.3 If it is impractical to determile background levels before
spiking (e.g., maximum holding times will be exceeded), the spike
concentration should be (1) the regulatory concentration limit, if any;
or, if none (2) the larger of either 5 times higher than the expected
background concentration or the test concentration in Section 8.2.2.
8.3.2 Analyze one sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second sample aliquot with 1.0 mL
of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100 (A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 2. These acceptance
criteria were calculated to include an allowance for error in
measurement

[[Page 144]]

of both the background and spike concentrations, assuming a spike to
background ratio of 5:1. This error will be accounted for to the extent
that the analyst's spike to background ratio approaches 5:1.\7\ If
spiking was performed at a concentration lower than the test
concentration in Section 8.2.2, the analyst must use either the QC
acceptance criteria in Table 2, or optional QC acceptance criteria
calculated for the specific spike concentration. To calculate optional
acceptance criteria for the recovery of a parameter: (1) Calculate
accuracy (X') using the equation in Table 3, substituting the spike
concentration (T) for C; (2) calculate overall precision (S') using the
equation in Table 3, substituting X' for X8; (3) calculate the range for
recovery at the spike concentration as (100 X'/T) +-2.44 (100 S'/T)%.\7\
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter that failed the criteria must be
analyzed as described in Section 8.4.
8.4. If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory.
8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The
QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
2. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of QC program for the laboratory, method accuracy for
wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2sp to P+2sp.
If P=90% and sp = 10%, for example, the accuracy interval is
expressed as 70-110%. Update the accuracy assessment for each parameter
on a regular basis (e.g. after each five to ten new accuracy
measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates may be analyzed to assess the
precision of the environmental measurements. When doubt exists over the
identification of a peak on the chromatogram, confirmatory techniques
such as gas chromatography with a dissimilar column, specific element
detector, or mass spectrometer must be used. Whenever possible, the
laboratory should analyze standard reference materials and participate
in relevant performance evaluation studies.

9. Sample Collection, Preservation, and Handling

10. Sample Extraction

[[Page 145]]

of the emulsion through glass wool, centrifugation, or other physical
methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer
flask.
10.3 Add a second 60-mL volume of methylene chloride to the sample
bottle and repeat the extraction procedure a second time, combining the
extracts in the Erlenmeyer flask. Perform a third extraction in the same
manner.
10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-
mL concentrator tube to a 500-mL evaporative flask. Other concentration
devices or techniques may be used in place of the K-D concentrator if
the requirements of Section 8.2 are met.
10.5 Pour the combined extract through a solvent-rinsed drying
column containing about 10 cm of anhydrous sodium sulfate, and collect
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and
column with 20 to 30 mL of methylene chloride to complete the
quantitative transfer.
10.6 Sections 10.7 and 10.8 describe a procedure for exchanging the
methylene chloride solvent to hexane while concentrating the extract
volume to 1.0 mL. When it is not necessary to achieve the MDL in Table
2, the solvent exchange may be made by the addition of 50 mL of hexane
and concentration to 10 mL as described in Method 606, Sections 10.7 and
10.8.
10.7 Add one or two clean boiling chips to the evaporative flask and
attach a three-ball Snyder column. Prewet the Snyder column by adding
about 1 mL of methylene chloride to the top. Place the K-D apparatus on
a hot water bath (60 to 65 [deg]C) so that the concentrator tube is
partially immersed in the hot water, and the entire lower rounded
surface of the flask is bathed with hot vapor. Adjust the vertical
position of the apparatus and the water temperature as required to
complete the concentration in 15 to 20 min. At the proper rate of
distillation the balls of the column will actively chatter but the
chambers will not flood with condensed solvent. When the apparent volume
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain
and cool for at least 10 min.
10.8 Remove the Snyder column and rinse the flask and its lower
joint into the concentrator tube with 1 to 2 mL of methylene chloride. A
5-mL syringe is recommended for this operation. Add 1 to 2 mL of hexane
and a clean boiling chip to the concentrator tube and attach a two-ball
micro-Snyder column. Prewet the column by adding about 0.5 mL of hexane
to the top. Place the micro-K-D apparatus on a hot water bath (60 to 65
[deg]C) so that the concentrator tube is partially immersed in the hot
water. Adjust the vertical position of the apparatus and the water
temperature as required to complete the concentration in 5 to 10 min. At
the proper rate of distillation the balls of the column will actively
chatter but the chambers will not flood. When the apparent volume of
liquid reaches 0.5 mL, remove the K-D apparatus and allow it to drain
and cool for at least 10 min.
10.9 Remove the micro-Snyder column and rinse its lower joint into
the concentrator tube with a minimum amount of hexane. Adjust the
extract volume to 1.0 mL. Stopper the concentrator tube and store
refrigerated if further processing will not be performed immediately. If
the extract will be stored longer than two days, it should be
transferred to a Teflon-sealed screw-cap vial. If the sample extract
requires no further cleanup, proceed with gas chromatographic analysis
(Section 12). If the sample requires further cleanup, proceed to Section
11.
10.10 Determine the original sample volume by refilling the sample
bottle to the mark and transferring the liquid to a 1000-mL graduated
cylinder. Record the sample volume to the nearest 5 mL.

11. Cleanup and Separation

12. Gas Chromatography

12.1 Isophorone and nitrobenzene are analyzed by injection of a
portion of the extract into an FIDGC. The dinitrotoluenes are analyzed
by a separate injection into an ECDGC.

[[Page 146]]

Table 1 summarizes the recommended operating conditions for the gas
chromatograph. Included in this table are retention times and MDL that
can be achieved under these conditions. Examples of the separations
achieved by Column 1 are shown in Figures 1 and 2. Other packed or
capillary (open-tubular) columns, chromatographic conditions, or
detectors may be used if the requirements of Section 8.2 are met.
12.2 Calibrate the system daily as described in Section 7.
12.3 If the internal standard calibration procedure is being used,
the internal standard must be added to the same extract and mixed
thoroughly immediately before injection into the gas chromatograph.
12.4 Inject 2 to 5 [mu]L of the sample extract or standard into the
gas chromatograph using the solvent-flush technique.\9\ Smaller (1.0
[mu]L) volumes may be injected if automatic devices are employed. Record
the volume injected to the nearest 0.05 [mu]L, the total extract volume,
and the resulting peak size in area or peak height units.
12.5 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
can be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.
12.6 If the response for a peak exceeds the working range of the
system, dilute the extract and reanalyze.
12.7 If the measurement of the peak response is prevented by the
presence of interferences, further cleanup is required.

13. Calculations

Equation 2

where:
A=Amount of material injected (ng).
Vi=Volume of extract injected ([mu]L).
Vt=Volume of total extract ([mu]L).
Vs=Volume of water extracted (mL).

Equation 3

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Is=Amount of internal standard added to each extract ([mu]g).
Vo=Volume of water extracted (L).

13.2 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

14. Method Performance

14.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and reported with 99%
confidence that the value is above zero.\1\ The MDL concentrations
listed in Table 1 were obtained using reagent water.\10\ Similar results
were achieved using representative wastewaters. The MDL actually
achieved in a given analysis will vary depending on instrument
sensitivity and matrix effects.
14.2 This method has been tested for linearity of spike recovery
from reagent water and has been demonstrated to be applicable over the
concentration range from 7xMDL to 1000xMDL.\10\
14.3 This method was tested by 18 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
at six concentrations over the range 1.0 to 515 [mu]g/L.\11\ Single
operator precision, overall precision, and method accuracy were found to
be directly related to the concentration of the parameter and
essentially independent of the sample matrix. Linear equations to
describe these relationships are presented in Table 3.

References

1. 40 CFR part 136, appendix B.
2. ``Determination of Nitroaromatic Compounds and Isophorone in
Industrial and Municipal Wastewaters,'' EPA 600/ 4-82-024, National
Technical Information Service, PB82-208398, Springfield, Virginia 22161,
May 1982.
3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard
Practices for Preparation of Sample Containers and for Preservation of
Organic Constituents,'' American Society for Testing and Materials,
Philadelphia.

[[Page 147]]

4. ``Carcinogens--Working With Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
6. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3 is two times the value 1.22
derived in this report.)
8. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard
Practices for Sampling Water,'' American Society for Testing and
Materials, Philadelphia.
9. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis;
Some Practical Aspects,'' Journal of the Association of Official
Analytical Chemists, 48, 1037 (1965).
10. ``Determination of Method Detection Limit and Analytical Curve
for EPA Method 609--Nitroaromatics and Isophorone,'' Special letter
report for EPA Contract 68-03-2624, U.S. Environmental Protection
Agency, Environmental Monitoring and Support Laboratory, Cincinnati,
Ohio 45268, June 1980.
11. ``EPA Method Study 19, Method 609 (Nitroaromatics and
Isophorone),'' EPA 600/4-84-018, National Technical Information Service,
PB84-176908, Springfield, Virginia 22161, March 1984.

Table 1--Chromatographic Conditions and Method Detection Limits
----------------------------------------------------------------------------------------------------------------
Retention time (min) Method detection limit
---------------------------- ([mu]g/L)
Parameter ---------------------------
Col. 1 Col. 2 ECDGC FIDGC
----------------------------------------------------------------------------------------------------------------
Nitrobenzene............................................ 3.31 4.31 13.7 3.6
2,6-Dinitrotoluene...................................... 3.52 4.75 0.01 -
Isophorone.............................................. 4.49 5.72 15.7 5.7
2,4-Dinitrotoluene...................................... 5.35 6.54 0.02 -
----------------------------------------------------------------------------------------------------------------
AAColumn 1 conditions: Gas-Chrom Q (80/100 mesh) coated with 1.95% QF-1/1.5% OV-17 packed in a 1.2 m long x 2
mm or 4 mm ID glass column. A 2 mm ID column and nitrogen carrier gas at 44 mL/min flow rate were used when
determining isophorone and nitrobenzene by FIDGC. The column temperature was held isothermal at 85 [deg]C. A 4
mm ID column and 10% methane/90% argon carrier gas at 44 mL/min flow rate were used when determining the
dinitrotol[chyph]uenes by ECDGC. The column temperature was held iso[chyph]thermal at 145 [deg]C.
AAColumn 2 conditions: Gas-Chrom Q (80/100 mesh) coated with 3% OV-101 packed in a 3.0 m long x 2 mm or 4 mm ID
glass column. A 2 mm ID column and nitrogen carrier gas at 44 mL/min flow rate were used when determining
isophorone and nitrobenzene by FIDGC. The column temperature was held isothermal at 100 [deg]C. A 4 mm ID
column and 10% methane/90% argon carrier gas at 44 mL/min flow rate were used when determining the
dinitrotoluenes by ECDGC. The column temperature was held isothermal at 150 [deg]C.

Table 2--QC Acceptance Criteria--Method 609
----------------------------------------------------------------------------------------------------------------
Range for X
Parameter Test Conc. Limit for s ([mu]g/L) Range for
([mu]g/L) ([mu]g/L) P, Ps (%)
----------------------------------------------------------------------------------------------------------------
2,4-Dinitrotoluene........................................ 20 5.1 3.6-22.8 6-125
2,6-Dinitrotoluene........................................ 20 4.8 3.8-23.0 8-126
Isophorone................................................ 100 32.3 8.0-100.0 D-117
Nitrobenzene.............................................. 100 33.3 25.7-100.0 6-118
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).
D=Detected; result must be greater than zero.

Table 3--Method Accuracy and Precision as Functions of Concentration--Method 609
----------------------------------------------------------------------------------------------------------------
Accuracy, as Single analyst Overall
Parameter recovery, X' precision, sr' precision, S'
([mu]g/L) ([mu]g/L) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
2,4-Dinitro-
toluene............................................... 0.65C+0.22 0.20X+0.08 0.37X-0.07
2,6-Dinitro-
toluene............................................... 0.66C+0.20 0.19X+0.06 0.36X-0.00
Isophorone............................................. 0.49C+2.93 0.28X+2.77 0.46X+0.31
Nitrobenzene........................................... 0.60C+2.00 0.25X+2.53 0.37X-0.78
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
sr'=Expected single analyst standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in [mu]g/
L.
C=True value for the concentration, in [mu]g/L.
X=Average recovery found for measurements of samples containing a concentration of C, in [mu]g/L.

[[Page 148]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.029

[[Page 149]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.030

[[Page 150]]

Method 610--Polynuclear Aromatic Hydrocarbons

1. Scope and Application

1.1 This method covers the determination of certain polynuclear
aromatic hydrocarbons (PAH). The following parameters can be determined
by this method:

1.2 This is a chromatographic method applicable to the determination
of the compounds listed above in municipal and industrial discharges as
provided under 40 CFR 136.1. When this method is used to analyze
unfamiliar samples for any or all of the compounds above, compound
identifications should be supported by at least one additional
qualitative technique. Method 625 provides gas chromatograph/mass
spectrometer (GC/MS) conditions appropriate for the qualitative and
quantitative confirmation of results for many of the parameters listed
above, using the extract produced by this method.
1.3 This method provides for both high performance liquid
chromatographic (HPLC) and gas chromatographic (GC) approaches for the
determination of PAHs. The gas chromatographic procedure does not
adequately resolve the following four pairs of compounds: Anthracene and
phenanthrene; chrysene and benzo(a)anthracene; benzo(b)fluoranthene and
benzo(k)fluoranthene; and dibenzo(a,h) anthracene and indeno (1,2,3-
cd)pyrene. Unless the purpose for the analysis can be served by
reporting the sum of an unresolved pair, the liquid chromatographic
approach must be used for these compounds. The liquid chromatographic
method does resolve all 16 of the PAHs listed.
1.4 The method detection limit (MDL, defined in Section 15.1) \1\
for each parameter is listed in Table 1. The MDL for a specific
wastewater may differ from those listed, depending upon the nature of
interferences in the sample matrix.
1.5 The sample extraction and concentration steps in this method are
essentially the same as in Methods 606, 608, 609, 611, and 612. Thus, a
single sample may be extracted to measure the parameters included in the
scope of each of these methods. When cleanup is required, the
concentration levels must be high enough to permit selecting aliquots,
as necessary, to apply appropriate cleanup procedures. Selection of the
aliquots must be made prior to the solvent exchange steps of this
method. The analyst is allowed the latitude, under Sections 12 and 13,
to select chromatographic conditions appropriate for the simultaneous
measurement of combinations of these parameters.
1.6 Any modification of this method, beyond those expressly
permitted, shall be considered as a major modification subject to
application and approval of alternate test procedures under 40 CFR 136.4
and 136.5.
1.7 This method is restricted to use by or under the supervision of
analysts experienced in the use of HPLC and GC systems and in the
interpretation of liquid and gas chromatograms. Each analyst must
demonstrate the ability to generate acceptable results with this method
using the procedure described in Section 8.2.

2. Summary of Method

2.1 A measured volume of sample, approximately 1-L, is extracted
with methylene chloride using a separatory funnel. The methylene
chloride extract is dried and concentrated to a volume of 10 mL or less.
The extract is then separated by HPLC or GC. Ultraviolet (UV) and
fluorescence detectors are used with HPLC to identify and measure the
PAHs. A flame ionization detector is used with GC.\2\
2.2 The method provides a silica gel column cleanup procedure to aid
in the elimination of interferences that may be encountered.

3. Interferences

3.1 Method interferences may be caused by contaminants in solvents,
reagents, glassware, and other sample processing hardward that lead to
discrete artifacts and/or elevated baselines in the chromatograms. All
of these materials must be routinely demonstrated to be free from
interferences under the conditions of the analysis by running laboratory
reagent blanks as described in Section 8.1.3.
3.1.1 Glassware must be scrupulously cleaned.\3\ Clean all glassware
as soon as possible after use by rinsing with the last solvent used in
it. Solvent rinsing should be followed by detergent washing with hot
water, and rinses with tap water and distilled water. The glassware
should then be drained dry, and heated in a muffle furnace at 400 [deg]C
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not
be eliminated by this treatment. Solvent rinses with acetone and
pesticide quality hexane may be

[[Page 151]]

substituted for the muffle furnace heating. Thorough rinsing with such
solvents usually eliminates PCB interference. Volumetric ware should not
be heated in a muffle furnace. After drying and cooling, glassware
should be sealed and stored in a clean environment to prevent any
accumulation of dust or other contaminants. Store inverted or capped
with aluminum foil.
3.1.2 The use of high purity reagents and solvents helps to minimize
interference problems. Purification of solvents by distillation in all-
glass systems may be required.
3.2 Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary
considerably from source to source, depending upon the nature and
diversity of the industrial complex or municipality being sampled. The
cleanup procedure in Section 11 can be used to overcome many of these
interferences, but unique samples may require additional cleanup
approaches to achieve the MDL listed in Table 1.
3.3 The extent of interferences that may be encountered using liquid
chromatographic techniques has not been fully assessed. Although the
HPLC conditions described allow for a unique resolution of the specific
PAH compounds covered by this method, other PAH compounds may interfere.

4. Safety

4.1 The toxicity or carcinogenicity of each reagent used in this
method have not been precisely defined; however, each chemical compound
should be treated as a potential health hazard. From this viewpoint,
exposure to these chemicals must be reduced to the lowest possible level
by whatever means available. The laboratory is responsible for
maintaining a current awareness file of OSHA regulations regarding the
safe handling of the chemicals specified in this method. A reference
file of material data handling sheets should also be made available to
all personnel involved in the chemical analysis. Additional references
to laboratory safety are available and have been identified
\4\^-\6\ for the information of the analyst.
4.2 The following parameters covered by this method have been
tentatively classified as known or suspected, human or mammalian
carcinogens: benzo(a)anthracene, benzo(a)pyrene, and dibenzo(a,h)-
anthracene. Primary standards of these toxic compounds should be
prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be
worn when the analyst handles high concentrations of these toxic
compounds.

5. Apparatus and Materials

5.1 Sampling equipment, for discrete or composite sampling.
5.1.1 Grab sample bottle--1-L or 1-qt, amber glass, fitted with a
screw cap lined with Teflon. Foil may be substituted for Teflon if the
sample is not corrosive. If amber bottles are not available, protect
samples from light. The bottle and cap liner must be washed, rinsed with
acetone or methylene chloride, and dried before use to minimize
contamination.
5.1.2 Automatic sampler (optional)--The sampler must incorporate
glass sample containers for the collection of a minimum of 250 mL of
sample. Sample containers must be kept refrigerated at 4 [deg]C and
protected from light during compositing. If the sampler uses a
peristaltic pump, a minimum length of compressible silicone rubber
tubing may be used. Before use, however, the compressible tubing should
be thoroughly rinsed with methanol, followed by repeated rinsings with
distilled water to minimize the potential for contamination of the
sample. An integrating flow meter is required to collect flow
proportional composites.
5.2 Glassware (All specifications are suggested. Catalog numbers are
included for illustration only.):
5.2.1 Separatory funnel--2-L, with Teflon stopcock.
5.2.2 Drying column--Chromatographic column, approximately 400 mm
long x 19 mm ID, with coarse frit filter disc.
5.2.3 Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes K-
570050-1025 or equivalent). Calibration must be checked at the volumes
employed in the test. Ground glass stopper is used to prevent
evaporation of extracts.
5.2.4 Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
5.2.5 Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
5.2.6 Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
5.2.7 Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
5.2.8 Chromatographic column--250 mm long x 10 mm ID, with coarse
frit filter disc at bottom and Teflon stopcock.
5.3 Boiling chips--Approximately 10/40 mesh. Heat to 400 [deg]C for
30 min or Soxhlet extract with methylene chloride.
5.4 Water bath--Heated, with concentric ring cover, capable of
temperature control (+-2 [deg]C). The bath should be used in a hood.
5.5 Balance--Analytical, capable of accurately weighing 0.0001 g.
5.6 High performance liquid chromatograph (HPLC)--An analytical
system complete with column supplies, high pressure syringes, detectors,
and compatible strip-chart recorder. A data system is recommended for
measuring peak areas and retention times.
5.6.1 Gradient pumping system--Constant flow.

[[Page 152]]

5.6.2 Reverse phase column--HC-ODS Sil-X, 5 micron particle
diameter, in a 25 cm x 2.6 mm ID stainless steel column (Perkin Elmer
No. 089-0716 or equivalent). This column was used to develop the method
performance statements in Section 15. Guidelines for the use of
alternate column packings are provided in Section 12.2.
5.6.3 Detectors--Fluorescence and/or UV detectors. The fluorescence
detector is used for excitation at 280 nm and emission greater than 389
nm cutoff (Corning 3-75 or equivalent). Fluorometers should have
dispersive optics for excitation and can utilize either filter or
dispersive optics at the emission detector. The UV detector is used at
254 nm and should be coupled to the fluorescence detector. These
detectors were used to develop the method performance statements in
Section 15. Guidelines for the use of alternate detectors are provided
in Section 12.2.
5.7 Gas chromatograph--An analytical system complete with
temperature programmable gas chromatograph suitable for on-column or
splitless injection and all required accessories including syringes,
analytical columns, gases, detector, and strip-chart recorder. A data
system is recommended for measuring peak areas.
5.7.1 Column--1.8 m long x 2 mm ID glass, packed with 3% OV-17 on
Chromosorb W-AW-DCMS (100/120 mesh) or equivalent. This column was used
to develop the retention time data in Table 2. Guidelines for the use of
alternate column packings are provided in Section 13.3.
5.7.2 Detector--Flame ionization detector. This detector has proven
effective in the analysis of wastewaters for the parameters listed in
the scope (Section 1.1), excluding the four pairs of unresolved
compounds listed in Section 1.3. Guidelines for the use of alternate
detectors are provided in Section 13.3.

6. Reagents

6.1 Reagent water--Reagent water is defined as a water in which an
interferent is not observed at the MDL of the parameters of interest.
6.2 Sodium thiosulfate--(ACS) Granular.
6.3 Cyclohexane, methanol, acetone, methylene chloride, pentane--
Pesticide quality or equivalent.
6.4 Acetonitrile--HPLC quality, distilled in glass.
6.5 Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at
400 [deg]C for 4 h in a shallow tray.
6.6 Silica gel--100/200 mesh, desiccant, Davison, grade-923 or
equivalent. Before use, activate for at least 16 h at 130 [deg]C in a
shallow glass tray, loosely covered with foil.
6.7 Stock standard solutions (1.00 [mu]g/[mu]L)--Stock standard
solutions can be prepared from pure standard materials or purchased as
certified solutions.
6.7.1 Prepare stock standard solutions by accurately weighing about
0.0100 g of pure material. Dissolve the material in acetonitrile and
dilute to volume in a 10-mL volumetric flask. Larger volumes can be used
at the convenience of the analyst. When com[chyph]pound purity is
assayed to be 96% or greater, [chyph]the weight can be used without
cor[chyph]rection to calculate the concentration of the stock standard.
Commercially prepared stock standards can be used at any concentration
if they are certified by the manufacturer or by an independent source.
6.7.2 Transfer the stock standard solutions into Teflon-sealed
screw-cap bottles. Store at 4 [deg]C and protect from light. Stock
standard solutions should be checked frequently for signs of degradation
or evaporation, especially just prior to preparing calibration standards
from them.
6.7.3 Stock standard solutions must be replaced after six months, or
sooner if comparison with check standards indicates a problem.
6.8 Quality control check sample concentrate--See Section 8.2.1.

7. Calibration

7.1 Establish liquid or gas chroma[chyph]tog[chyph]ra[chyph]phic
operating conditions equivalent to those given in Table 1 or 2. The
chromatographic system can be calibrated using the external standard
technique (Section 7.2) or the internal standard technique (Section
7.3).
7.2 External standard calibration procedure:
7.2.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask and diluting to volume
with acetonitrile. One of the external standards should be at a
concentration near, but above, the MDL (Table 1) and the other
concentrations should correspond to the expected range of concentrations
found in real samples or should define the working range of the
detector.
7.2.2 Using injections of 5 to 25 [mu]L for HPLC and 2 to 5 [mu]L
for GC, analyze each calibration standard according to Section 12 or 13,
as appropriate. Tabulate peak height or area responses against the mass
injected. The results can be used to prepare a calibration curve for
each compound. Alternatively, if the ratio of response to amount
injected (calibration factor) is a constant over the working range (<10%
relative standard deviation, RSD), linearity through the origin can be
assumed and the average ratio or calibration factor can be used in place
of a calibration curve.
7.3 Internal standard calibration procedure--To use this approach,
the analyst must select one or more internal standards that are similar
in analytical behavior to the

[[Page 153]]

compounds of interest. The analyst must further demonstrate that the
measurement of the internal standard is not affected by method or matrix
interferences. Because of these limitations, no internal standard can be
suggested that is applicable to all samples.
7.3.1 Prepare calibration standards at a minimum of three
concentration levels for each parameter of interest by adding volumes of
one or more stock standards to a volumetric flask. To each calibration
standard, add a known constant amount of one or more internal standards,
and dilute to volume with acetonitrile. One of the standards should be
at a concentration near, but above, the MDL and the other concentrations
should correspond to the expected range of concentrations found in real
samples or should define the working range of the detector.
7.3.2 Using injections of 5 to 25 [mu]L for HPLC and 2 to 5 [mu]L
for GC, analyze each calibration standard according to Section 12 or 13,
as appropriate. Tabulate peak height or area responses against
concentration for each compound and internal standard. Calculate
response factors (RF) for each compound using Equation 1.
[GRAPHIC] [TIFF OMITTED] TC15NO91.113

Equation 1

7.4 The working calibration curve, calibration factor, or RF must be
verified on each working day by the measurement of one or more
calibration standards. If the response for any parameter varies from the
predicted response by more than +-15%, the test must be repeated using a
fresh calibration standard. Alternatively, a new calibration curve must
be prepared for that compound.
7.5 Before using any cleanup procedure, the analyst must process a
series of calibration standards through the procedure to validate
elution patterns and the absence of interferences from the reagents.

8. Quality Control

[[Page 154]]

of the six early-eluting PAHs (naphthalene, acenaphthylene,
acenaphthene, fluorene, phenanthrene, and anthracene); 5 [mu]g/mL of
benzo(k)fluoranthene; and 10 [mu]g/mL of any of the other PAHs. The QC
check sample concentrate must be obtained from the U.S. Environmental
Protection Agency, Environmental Monitoring and Support Laboratory in
Cincinnati, Ohio, if available. If not available from that source, the
QC check sample concentrate must be obtained from another external
source. If not available from either source above, the QC check sample
concentrate must be prepared by the laboratory using stock standards
prepared independently from those used for calibration.
8.2.2 Using a pipet, prepare QC check samples at the test
concentrations shown in Table 3 by adding 1.00 mL of QC check sample
concentrate to each of four 1-L aliquots of reagent water.
8.2.3 Analyze the well-mixed QC check samples according to the
method beginning in Section 10.
8.2.4 Calculate the average recovery (X) in [mu]g/L, and the
standard deviation of the recovery (s) in [mu]g/L, for each parameter
using the four results.
8.2.5 For each parameter compare s and X with the corresponding
acceptance criteria for precision and accuracy, respectively, found in
Table 3. If s and X for all parameters of interest meet the acceptance
criteria, the system performance is acceptable and analysis of actual
samples can begin. If any individual s exceeds the precision limit or
any individual X falls outside the range for accuracy, the system
performance is unacceptable for that parameter.
Note: The large number of parameters in Table 3 present a
substantial probability that one or more will fail at least one of the
acceptance criteria when all parameters are analyzed.
8.2.6 When one or more of the parameters tested fail at least one of
the acceptance criteria, the analyst must proceed according to Section
8.2.6.1 or 8.2.6.2.
8.2.6.1 Locate and correct the source of the problem and repeat the
test for all parameters of interest beginning with Section 8.2.2.
8.2.6.2 Beginning with Section 8.2.2, repeat the test only for those
parameters that failed to meet criteria. Repeated failure, however, will
confirm a general problem with the measurement system. If this occurs,
locate and correct the source of the problem and repeat the test for all
compounds of interest beginning with Section 8.2.2.
8.3 The laboratory must, on an ongoing basis, spike at least 10% of
the samples from each sample site being monitored to assess accuracy.
For laboratories analyzing one to ten samples per month, at least one
spiked sample per month is required.
8.3.1 The concentration of the spike in the sample should be
determined as follows:
8.3.1.1 If, as in compliance monitoring, the concentration of a
specific parameter in the sample is being checked against a regulatory
concentration limit, the spike should be at that limit or 1 to 5 times
higher than the background concentration determined in Section 8.3.2,
whichever concentration would be larger.
8.3.1.2 If the concentration of a specific parameter in the sample
is not being checked against a limit specific to that parameter, the
spike should be at the test concentration in Section 8.2.2 or 1 to 5
times higher than the background concentration determined in Section
8.3.2, whichever concentration would be larger.
8.3.1.3 If it is impractical to determine background levels before
spiking (e.g., maximum holding times will be exceeded), the spike
concentration should be (1) the regulatory concentration limit, if any;
or, if none, (2) the larger of either 5 times higher than the expected
background concentration or the test concentration in Section 8.2.2.
8.3.2 Analyze one sample aliquot to determine the background
concentration (B) of each parameter. If necessary, prepare a new QC
check sample concentrate (Section 8.2.1) appropriate for the background
concentrations in the sample. Spike a second sample aliquot with 1.0 mL
of the QC check sample concentrate and analyze it to determine the
concentration after spiking (A) of each parameter. Calculate each
percent recovery (P) as 100 (A-B)%/T, where T is the known true value of
the spike.
8.3.3 Compare the percent recovery (P) for each parameter with the
corresponding QC acceptance criteria found in Table 3. These acceptance
criteria were calculated to include an allowance for error in
measurement of both the background and spike concentrations, assuming a
spike to background ratio of 5:1. This error will be accounted for to
the extent that the analyst's spike to background ratio approaches
5:1.\7\ If spiking was performed at a concentration lower than the test
concentration in Section 8.2.2, the analyst must use either the QC
acceptance criteria in Table 3, or optional QC acceptance criteria
calculated for the specific spike concentration. To calculate optional
acceptance criteria for the recovery of a parameter: (1) Calculate
accuracy (X') using the equation in Table 4, substituting the spike
concentration (T) for C; (2) calculate overall precision (S') using the
equation in Table 4, substituting X' for X; (3) calculate the range for
recovery at the spike concentration as (100 X'/T)+-2.44(100 S'/T)%.\7\
8.3.4 If any individual P falls outside the designated range for
recovery, that parameter has failed the acceptance criteria. A check
standard containing each parameter

[[Page 155]]

that failed the critiera must be analyzed as described in Section 8.4.
8.4 If any parameter fails the acceptance criteria for recovery in
Section 8.3, a QC check standard containing each parameter that failed
must be prepared and analyzed.
Note: The frequency for the required analysis of a QC check standard
will depend upon the number of parameters being simultaneously tested,
the complexity of the sample matrix, and the performance of the
laboratory. If the entire list of parameters in Table 3 must be measured
in the sample in Section 8.3, the probability that the analysis of a QC
check standard will be required is high. In this case the QC check
standard should be routinely analyzed with the spike sample.
8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The
QC check standard needs only to contain the parameters that failed
criteria in the test in Section 8.3.
8.4.2 Analyze the QC check standard to determine the concentration
measured (A) of each parameter. Calculate each percent recovery
(Ps) as 100 (A/T)%, where T is the true value of the standard
concentration.
8.4.3 Compare the percent recovery (Ps) for each
parameter with the corresponding QC acceptance criteria found in Table
3. Only parameters that failed the test in Section 8.3 need to be
compared with these criteria. If the recovery of any such parameter
falls outside the designated range, the laboratory performance for that
parameter is judged to be out of control, and the problem must be
immediately identified and corrected. The analytical result for that
parameter in the unspiked sample is suspect and may not be reported for
regulatory compliance purposes.
8.5 As part of the QC program for the laboratory, method accuracy
for wastewater samples must be assessed and records must be maintained.
After the analysis of five spiked wastewater samples as in Section 8.3,
calculate the average percent recovery (P) and the standard deviation of
the percent recovery (sp). Express the accuracy assessment as
a percent recovery interval from P-2sp to P+2sp.
If P=90% and sp=10%, for example, the accuracy interval is
expressed as 70-110%. Update the accuracy assessment for each parameter
on a regular basis (e.g. after each five to ten new accuracy
measurements).
8.6 It is recommended that the laboratory adopt additional quality
assurance practices for use with this method. The specific practices
that are most productive depend upon the needs of the laboratory and the
nature of the samples. Field duplicates may be analyzed to assess the
precision of the environmental measurements. When doubt exists over the
identification of a peak on the chromatogram, confirmatory techniques
such as gas chromatography with a dissimilar column, specific element
detector, or mass spectrometer must be used. Whenever possible, the
laboratory should analyze standard reference materials and participate
in relevant performance evaluation studies.

9. Sample Collection, Preservation, and Handling

9.1 Grab samples must be collected in glass containers. Conventional
sampling practices \8\ should be followed, except that the bottle must
not be prerinsed with sample before collection. Composite samples should
be collected in refrigerated glass containers in accordance with the
requirements of the program. Automatic sampling equipment must be as
free as possible of Tygon tubing and other potential sources of
contamination.
9.2 All samples must be iced or refrigerated at 4 [deg]C from the
time of collection until extraction. PAHs are known to be light
sensitive; therefore, samples, extracts, and standards should be stored
in amber or foil-wrapped bottles in order to minimize photolytic
decomposition. Fill the sample bottles and, if residual chlorine is
present, add 80 mg of sodium thiosulfate per liter of sample and mix
well. EPA Methods 330.4 and 330.5 may be used for measurement of
residual chlorine.\9\ Field test kits are available for this purpose.
9.3 All samples must be extracted within 7 days of collection and
completely analyzed within 40 days of extraction.\2\

10. Sample Extraction

[[Page 156]]

10.4 Assemble a Kuderna-Danish (K-D) concentrator by attaching a 10-
mL concentrator tube to a 500-mL evaporative flask. Other concentration
devices or techniques may be used in place of the K-D concentrator if
the requirements of Section 8.2 are met.
10.5 Pour the combined extract through a solvent-rinsed drying
column containing about 10 cm of anhydrous sodium sulfate, and collect
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and
column with 20 to 30 mL of methylene chloride to complete the
quantitative transfer.
10.6 Add one or two clean boiling chips to the evaporative flask and
attach a three-ball Snyder column. Prewet the Snyder column by adding
about 1 mL of methylene chloride to the top. Place the K-D apparatus on
a hot water bath (60 to 65 [deg]C) so that the concentrator tube is
partially immersed in the hot water, and the entire lower rounded
surface of the flask is bathed with hot vapor. Adjust the vertical
position of the apparatus and the water temperature as required to
complete the concentration in 15 to 20 min. At the proper rate of
distillation the balls of the column will actively chatter but the
chambers will not flood with condensed solvent. When the apparent volume
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain
and cool for at least 10 min.
10.7 Remove the Snyder column and rinse the flask and its lower
joint into the concentrator tube with 1 to 2 mL of methylene chloride. A
5-mL syringe is recommended for this operation. Stopper the concentrator
tube and store refrigerated if further processing will not be performed
immediately. If the extract will be stored longer than two days, it
should be transferred to a Teflon-sealed screw-cap vial and protected
from light. If the sample extract requires no further cleanup, proceed
with gas or liquid chromatographic analysis (Section 12 or 13). If the
sample requires further cleanup, proceed to Section 11.
10.8 Determine the original sample volume by refilling the sample
bottle to the mark and transferring the liquid to a 1000-mL graduated
cylinder. Record the sample volume to the nearest 5 mL.

11. Cleanup and Separation

11.1 Cleanup procedures may not be necessary for a relatively clean
sample matrix. If particular circumstances demand the use of a cleanup
procedure, the analyst may use the procedure below or any other
appropriate procedure. However, the analyst first must demonstrate that
the requirements of Section 8.2 can be met using the methods as revised
to incorporate the cleanup procedure.
11.2 Before the silica gel cleanup technique can be utilized, the
extract solvent must be exchanged to cyclohexane. Add 1 to 10 mL of the
sample extract (in methylene chloride) and a boiling chip to a clean K-D
concentrator tube. Add 4 mL of cyclohexane and attach a two-ball micro-
Snyder column. Prewet the column by adding 0.5 mL of methylene chloride
to the top. Place the micro-K-D apparatus on a boiling (100 [deg]C)
water bath so that the concentrator tube is partially immersed in the
hot water. Adjust the vertical position of the apparatus and the water
temperature as required to complete concentration in 5 to 10 min. At the
proper rate of distillation the balls of the column will actively
chatter but the chambers will not flood. When the apparent volume of the
liquid reaches 0.5 mL, remove the K-D apparatus and allow it to drain
and cool for at least 10 min. Remove the micro-Snyder column and rinse
its lower joint into the concentrator tube with a minimum amount of
cyclohexane. Adjust the extract volume to about 2 mL.
11.3 Silica gel column cleanup for PAHs:
11.3.1 Prepare a slurry of 10 g of activiated silica gel in
methylene chloride and place this into a 10-mm ID chromatographic
column. Tap the column to settle the silica gel and elute the methylene
chloride. Add 1 to 2 cm of anhydrous sodium sulfate to the top of the
silica gel.
11.3.2 Preelute the column with 40 mL of pentane. The rate for all
elutions should be about 2 mL/min. Discard the eluate and just prior to
exposure of the sodium sulfate layer to the air, transfer the 2-mL
cyclohexane sample extract onto the column using an additional 2 mL
cyclohexane to complete the transfer. Just prior to exposure of the
sodium sulfate layer to the air, add 25 mL of pentane and continue the
elution of the column. Discard this pentane eluate.
11.3.3 Next, elute the column with 25 mL of methylene chloride/
pentane (4+6)(V/V) into a 500-mL K-D flask equipped with a 10-mL
concentrator tube. Concentrate the collected fraction to less than 10 mL
as in Section 10.6. When the apparatus is cool, remove the Snyder column
and rinse the flask and its lower joint with pentane. Proceed with HPLC
or GC analysis.

12. High Performance Liquid Chromatography

12.1 To the extract in the concentrator tube, add 4 mL of
acetonitrile and a new boiling chip, then attach a two-ball micro-Snyder
column. Concentrate the solvent as in Section 10.6, except set the water
bath at 95 to 100 [deg]C. When the apparatus is cool, remove the micro-
Snyder column and rinse its lower joint into the concentrator tube with
about 0.2 mL of acetonitrile. Adjust the extract volume to 1.0 mL.
12.2 Table 1 summarizes the recommended operating conditions for the
HPLC. Included in this table are retention times, capacity factors, and
MDL that can be achieved under

[[Page 157]]

these conditions. The UV detector is recommended for the determination
of naphthalene, acenaphthylene, acenapthene, and fluorene and the
fluorescence detector is recommended for the remaining PAHs. Examples of
the separations achieved by this HPLC column are shown in Figures 1 and
2. Other HPLC columns, chromatographic conditions, or detectors may be
used if the requirements of Section 8.2 are met.
12.3 Calibrate the system daily as described in Section 7.
12.4 If the internal standard calibration procedure is being used,
the internal standard must be added to the sample extract and mixed
thoroughly immediately before injection into the instrument.
12.5 Inject 5 to 25 [mu]L of the sample extract or standard into the
HPLC using a high pressure syringe or a constant volume sample injection
loop. Record the volume injected to the nearest 0.1 [mu]L, and the
resulting peak size in area or peak height units. Re-equilibrate the
HPLC column at the initial gradient conditions for at least 10 min
between injections.
12.6 Identify the parameters in the sam[chyph]ple by comparing the
retention time of [chyph]the peaks in the sample chromatogram with those
of [chyph]the peaks in standard chromatograms. The [chyph]width of the
retention time window used to make identifications should be based upon
measurements of actual retention time variations of standards over the
course of a day. Three times the standard deviation of a retention time
for a compound can be used to calculate a suggested window size;
however, the experience of the analyst should weigh heavily in the
interpretation of chromatograms.
12.7 If the response for a peak exceeds the working range of the
system, dilute the extract with acetonitrile and reanalyze.
12.8 If the measurement of the peak response is prevented by the
presence of interferences, further cleanup is required.

13. Gas Chromatography

13.1 The packed column GC procedure will not resolve certain
isomeric pairs as indicated in Section 1.3 and Table 2. The liquid
chromatographic procedure (Section 12) must be used for these
parameters.
13.2 To achieve maximum sensitivity with this method, the extract
must be concentrated to 1.0 mL. Add a clean boiling chip to the
methylene chloride extract in the concentrator tube. Attach a two-ball
micro-Snyder column. Prewet the micro-Snyder column by adding about 0.5
mL of methylene chloride to the top. Place the micro-K-D apparatus on a
hot water bath (60 to 65 [deg]C) so that the concentrator tube is
partially immersed in the hot water. Adjust the vertical position of the
apparatus and the water temperature as required to complete the
concentration in 5 to 10 min. At the proper rate of distillation the
balls will actively chatter but the chambers will not flood. When the
apparent volume of liquid reaches 0.5 mL, remove the K-D apparatus and
allow it to drain and cool for at least 10 min. Remove the micro-Snyder
column and rinse its lower joint into the concentrator tube with a
minimum amount of methylene chloride. Adjust the final volume to 1.0 mL
and stopper the concentrator tube.
13.3 Table 2 summarizes the recommended operating conditions for the
gas chromatograph. Included in this table are retention times that were
obtained under these conditions. An example of the separations achieved
by this column is shown in Figure 3. Other packed or capillary (open-
tubular) columns, chromatographic conditions, or detectors may be used
if the requirements of Section 8.2 are met.
13.4 Calibrate the gas chromatographic system daily as described in
Section 7.
13.5 If the internal standard calibration procedure is being used,
the internal standard must be added to the sample extract and mixed
thoroughly immediately before injection into the gas chromatograph.
13.6 Inject 2 to 5 [mu]L of the sample extract or standard into the
gas chromatograph using the solvent-flush technique.\10\ Smaller (1.0
[mu]L) volumes may be injected if automatic devices are employed. Record
the volume injected to the nearest 0.05 [mu]L, and the resulting peak
size in area or peak height units.
13.7 Identify the parameters in the sample by comparing the
retention times of the peaks in the sample chromatogram with those of
the peaks in standard chromatograms. The width of the retention time
window used to make identifications should be based upon measurements of
actual retention time variations of standards over the course of a day.
Three times the standard deviation of a retention time for a compound
can be used to calculate a suggested window size; however, the
experience of the analyst should weigh heavily in the interpretation of
chromatograms.
13.8 If the response for a peak exceeds the working range of the
system, dilute the extract and reanalyze.
13.9 If the measurement of the peak response is prevented by the
presence of interferences, further cleanup is required.

14. Calculations

14.1 Determine the concentration of individual compounds in the
sample.
14.1.1 If the external standard calibration procedure is used,
calculate the amount of material injected from the peak response using
the calibration curve or calibration factor determined in Section 7.2.2.
The concentration in the sample can be calculated from Equation 2.

[[Page 158]]

[GRAPHIC] [TIFF OMITTED] TC15NO91.114

Equation 2

where:
A=Amount of material injected (ng).
Vi=Volume of extract injected ([mu]L).
Vt=Volume of total extract ([mu]L).
Vs=Volume of water extracted (mL).

Equation 3

where:
As=Response for the parameter to be measured.
Ais=Response for the internal standard.
Is=Amount of internal standard added to each extract ([mu]g).
Vo=Volume of water extracted (L).

14.2 Report results in [mu]g/L without correction for recovery data.
All QC data obtained should be reported with the sample results.

15. Method Performance

15.1 The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be measured and reported with 99%
confidence that the value is above zero.\1\ The MDL concentrations
listed in Table 1 were obtained using reagent water.\11\ Similar results
were achieved using representative wastewaters. MDL for the GC approach
were not determined. The MDL actually achieved in a given analysis will
vary depending on instrument sensitivity and matrix effects.
15.2 This method has been tested for linearity of spike recovery
from reagent water and has been demonstrated to be applicable over the
concentration range from 8 x MDL to 800 x MDL\11\ with the following
exception: benzo(ghi)perylene recovery at 80 x and 800 x MDL were low
(35% and 45%, respectively).
15.3 This method was tested by 16 laboratories using reagent water,
drinking water, surface water, and three industrial wastewaters spiked
at six concentrations over the range 0.1 to 425 [mu]g/L.\12\ Single
operator precision, overall precision, and method accuracy were found to
be directly related to the concentration of the parameter and
essentially independent of the sample matrix. Linear equations to
describe these relationships are presented in Table 4.

References

1. 40 CFR part 136, appendix B.
2. ``Determination of Polynuclear Aromatic Hydrocarbons in
Industrial and Municipal Wastewaters,'' EPA 600/4-82-025, National
Technical Information Service, PB82-258799, Springfield, Virginia 22161,
June 1982.
3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard
Practices for Preparation of Sample Containers and for Preservation of
Organic Constituents,'' American Society for Testing and Materials,
Philadelphia.
4. ``Carcinogens--Working With Carcinogens,'' Department of Health,
Education, and Welfare, Public Health Service, Center for Disease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August 1977.
5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR
part 1910), Occupational Safety and Health Administration, OSHA 2206
(Revised, January 1976).
6. ``Safety in Academic Chemistry Laboratories,'' American Chemical
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44
used in the equation in Section 8.3.3 is two times the value 1.22
derived in this report.)
8. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard
Practices for Sampling Water,'' American Society for Testing and
Materials, Philadelphia.
9. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S.
Environmental Protection Agency, Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio 45268, March 1979.
10. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis;
Some Practical Aspects,'' Journal of the Association of Official
Analytical Chemists, 48, 1037 (1965).
11. Cole, T., Riggin, R., and Glaser, J. ``Evaluation of Method
Detection Limits and Analytical Curve for EPA Method 610--PNAs,''
International Symposium on Polynuclear Aromatic Hydrocarbons, 5th,
Battelle's Columbus Laboratories, Columbus, Ohio (1980).
12. ``EPA Method Study 20, Method 610 (PNA's),'' EPA 600/4-84-063,
National Technical Information Service, PB84-211614, Springfield,
Virginia 22161, June 1984.

[[Page 159]]

Table 1--High Performance Liquid Chromatography Conditions and Method
Detection Limits
------------------------------------------------------------------------
Method
Retention Column detection
Parameter time capacity limit
(min) factor ([mu]g/L)
(k') a
------------------------------------------------------------------------
Naphthalene........................... 16.6 12.2 1.8
Acenaphthylene........................ 18.5 13.7 2.3
Acenaphthene.......................... 20.5 15.2 1.8
Fluorene.............................. 21.2 15.8 0.21
Phenanthrene.......................... 22.1 16.6 0.64
Anthracene............................ 23.4 17.6 0.66
Fluoranthene.......................... 24.5 18.5 0.21
Pyrene................................ 25.4 19.1 0.27
Benzo(a)anthracene.................... 28.5 21.6 0.013
Chrysene.............................. 29.3 22.2 0.15
Benzo(b)fluoranthene.................. 31.6 24.0 0.018
Benzo(k)fluoranthene.................. 32.9 25.1 0.017
Benzo(a)pyrene........................ 33.9 25.9 0.023
Dibenzo(a,h)anthracene................ 35.7 27.4 0.030
Benzo(ghi)perylene.................... 36.3 27.8 0.076
Indeno(1,2,3-cd)pyrene................ 37.4 28.7 0.043
------------------------------------------------------------------------
AAAHPLC column conditions: Reverse phase HC-ODS Sil-X, 5 micron
particle size, in a 25 cm x 2.6 mm ID stainless steel column.
Isocratic elution for 5 min. using acetonitrile/water (4+6), then
linear gradient elution to 100% acetonitrile over 25 min. at 0.5 mL/
min flow rate. If columns having other internal diameters are used,
the flow rate should be adjusted to maintain a linear velocity of 2 mm/
sec.
a The MDL for naphthalene, acenaphthylene, acenaphthene, and fluorene
were determined using a UV detector. All others were determined using
a fluorescence detector.

Table 2--Gas Chromatographic Conditions and Retention Times
------------------------------------------------------------------------
Retention
Parameter time (min)
------------------------------------------------------------------------
Naphthalene................................................. 4.5
Acenaphthylene.............................................. 10.4
Acenaphthene................................................ 10.8
Fluorene.................................................... 12.6
Phenanthrene................................................ 15.9
Anthracene.................................................. 15.9
Fluoranthene................................................ 19.8
Pyrene...................................................... 20.6
Benzo(a)anthracene.......................................... 24.7
Chrysene.................................................... 24.7
Benzo(b)fluoranthene........................................ 28.0
Benzo(k)fluoranthene........................................ 28.0
Benzo(a)pyrene.............................................. 29.4
Dibenzo(a,h)anthracene...................................... 36.2
Indeno(1,2,3-cd)pyrene...................................... 36.2
Benzo(ghi)perylene.......................................... 38.6
------------------------------------------------------------------------
GC Column conditions: Chromosorb W-AW-DCMS (100/120 mesh) coated with 3%
OV-17 packed in a 1.8 x 2 mm ID glass column with nitrogen carrier gas
at 40 mL/min. flow rate. Column temperature was held at 100 [deg]C for
4 min., then programmed at 8 [deg]C/min. to a final hold at 280
[deg]C.

Table 3--QC Acceptance Criteria--Method 610
----------------------------------------------------------------------------------------------------------------
Range for X
Parameter Test conc. Limit for s ([mu]g/L) Range for
([mu]g/L) ([mu]g/L) P, Ps (%)
----------------------------------------------------------------------------------------------------------------
Acenaphthene................................................ 100 40.3 D-105.7 D-124
Acenaphthylene.............................................. 100 45.1 22.1-112.1 D-139
Anthracene.................................................. 100 28.7 11.2-112.3 D-126
Benzo(a)anthracene.......................................... 10 4.0 3.1-11.6 12-135
Benzo(a)pyrene.............................................. 10 4.0 0.2-11.0 D-128
Benzo(b)fluor-anthene....................................... 10 3.1 1.8-13.8 6-150
Benzo(ghi)perylene.......................................... 10 2.3 D-10.7 D-116
Benzo(k)fluo-ranthene....................................... 5 2.5 D-7.0 D-159
Chrysene.................................................... 10 4.2 D-17.5 D-199
Dibenzo(a,h)an-thracene..................................... 10 2.0 0.3-10.0 D-110
Fluoranthene................................................ 10 3.0 2.7-11.1 14-123
Fluorene.................................................... 100 43.0 D-119 D-142
Indeno(1,2,3-cd)pyrene...................................... 10 3.0 1.2-10.0 D-116
Naphthalene................................................. 100 40.7 21.5-100.0 D-122
Phenanthrene................................................ 100 37.7 8.4-133.7 D-155
Pyrene...................................................... 10 3.4 1.4-12.1 D-140
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in [mu]g/L (Section 8.2.4).
X=Average recovery for four recovery measurements, in [mu]g/L (Section 8.2.4).
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).
D=Detected; result must be greater than zero.

[[Page 160]]

Table 4--Method Accuracy and Precision as Functions of Concentration--Method 610
----------------------------------------------------------------------------------------------------------------
Accuracy, as Single analyst Overall
Parameter recovery, X' precision, sr' precision, S'
([mu]g/L) ([mu]g/L) ([mu]g/L)
----------------------------------------------------------------------------------------------------------------
Acenaphthene.................................................... 0.52C + 0.54 0.39X + 0.76 0.53X + 1.32
Acenaphthylene.................................................. 0.69C - 1.89 0.36X + 0.29 0.42X + 0.52
Anthracene...................................................... 0.63C - 1.26 0.23X + 1.16 0.41X + 0.45
Benzo(a)anthra[chyph]cene....................................... 0.73C + 0.05 0.28X + 0.04 0.34X + 0.02
Benzo(a)pyrene.................................................. 0.56C + 0.01 0.38X - 0.01 0.53X - 0.01
Benzo(b)fluoran[chyph]thene..................................... 0.78C + 0.01 0.21X + 0.01 0.38X - 0.00
Benzo(ghi)peryl[chyph]ene....................................... 0.44C + 0.30 0.25X + 0.04 0.58X + 0.10
Benzo(k)fluoran[chyph]thene..................................... 0.59C + 0.00 0.44X - 0.00 0.69X + 0.01
Chrysene........................................................ 0.77C - 0.18 0.32X - 0.18 0.66X - 0.22
Dibenzo(a,h)an[chyph]thracene................................... 0.41C + 0.11 0.24X + 0.02 0.45X + 0.03
Fluoranthene.................................................... 0.68C + 0.07 0.22X + 0.06 0.32X + 0.03
Fluorene........................................................ 0.56C - 0.52 0.44X - 1.12 0.63X - 0.65
Indeno(1,2,3-cd)pyrene.......................................... 0.54C + 0.06 0.29X + 0.02 0.42X + 0.01
Naphthalene..................................................... 0.57C - 0.70 0.39X - 0.18 0.41X + 0.74
Phenanthrene.................................................... 0.72C - 0.95 0.29X + 0.05 0.47X - 0.25
Pyrene.......................................................... 0.69C - 0.12 0.25X + 0.14 0.42X - 0.00
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in [mu]g/L.
sr'=Expected single analyst standard deviation of measurements at an aver