P882-156 076
                          THE DETERMINATION OF ORGANONITROGEN
                               PESTICIDES  IN  INDUSTRIAL
                               AND MUNICIPAL WASTBiATER

                                      Method  633
                                  Thomas A. Pressley
                                          and
                                  James E.  Longbottom
                         Physical and Chemical Methods Branch
                    Environmental Monitoring and Support Laboratory
                                Cincinnati, Ohio 45268
                                     January 1982
                    ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
                           OFFICE  OF  RESEARCH  AND DEVELOPMENT
                          U.S.  ENVIRONMENTAL PROTECTION AGENCY
                                CINCINNATI, OHIO 45268

-------
                THE DETERMINATION OF ORGANONITROGEN PESTICIDES
                    IN INDUSTRIAL AND MUNICIPAL WASTEWATER

                                  METHOD 633

1.  Scope and Application

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

         Parameter                  STORET No.                -  CAS No.

         Bromacil                    '  —                      314-40-9
         Deet                          ~                      134-62-3
         Hexazlnone                    —                    51235-04-2
         Metrfbuzin                   81408                  21087-64-9
         Terbacil                      —                     5902-51-2
         THadiraefon                   —                    43121-43-3
         Tricyclazole                  —                    41814-78-2

    1.2  This 1s a gas chromatographlc (GO) method applicable to the deter-
         mination of the compounds listed above in industrial and municipal
         discharges as provided under 40 CFR 136.1.  Any modification of
         this method beyond those expressly permitted, shall be considered a
         major modification subject to application and approval of alternate
         test procedures under 40 CFR 136.4 and 136.5.

    1.3  The method detection limit (MDL, defined 1n Section 15) for five of
         the parameters are 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  This method 1s restricted to use by or under the supervision of
         analysts experienced 1n the use of gas chromatography and in the
         interpretation of gas chromatograns.  Each analyst must demonstrate
         the ability to generate acceptable results with this method using
         the procedure described 1n Section 8.2.

    1.5  When this method 1s 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.
         Section 14 provides gas chromatograph/mass spectrometer (GC/MS)
         criteria appropriate for the qualitative confirmation of compound
         Identifications.

-------
2.  Summary of Method

    2.1  A measured volume of sample,  approximately  1-Hter,  is solvent
         extracted with methylene chloride using  a separatory funnel.  The
         raethylene chloride extract 1s dried  and  exchanged to acetone during
         concentration to a volume of  10 ml or  less.  Gas chrcmatographic
         conditions are described which permit  the separation and measure-
         ment of the compounds in the  extract by  gas chromatography with a
         thermionic bead detector.'

3.  Interferences

    3.1  Method Interferences may be caused by  contaminants in solvents,
         reagents,.glassware and other sample processing apparatus that lead
         to discrete artifacts or elevated baselines in gas chroraatograms.
         All reagents and apparatus must be routinely demonstrated to be
         free from interferences under the conditions of the  analysis by
         running laboratory reagent blanks as described in Section 8.5.

         3.1.1  Glassware must be scrupulously  cleaned.2  Clean all
                glassware as soon as possible after  use by thoroughly
                rinsing with the last  solvent used in it.  Follow by washing
                with hot water and detergent  and  thorough rinsing with tap
                and reagent water. Drain dry, and heat 1n an  oven or muffle
                furnace at 400°C for 15 to 30 m1n.  Do not heat volumetric
                ware.  Thermally stable materials such as PCBs, might not be
                eliminated by this treatment.   Thorough rinsing with acetone
                and pesticide quality hexane  may  be substituted for the
                heating.  After drying and cooling, seal and  store glassware
                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 mini-
                mize Interference problems.   Purification of  solvents by
                distillation 1n all-glass systems may be required.

    3.2  Matrix Interferences may be caused by  contaminants that are coex-
         tracted 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 sampled.
         Unique samples may require special cleanup, approaches to achieve
         the MOL listed 1n Table 1*
    4.1  The toxicity or cardnogenlcity of each reagent used in this method
         has not been precisely defined; however, each chemical compound
         must 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 1s 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 3-5 for the information of the analyst.

5.  Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.

         5.1.1  Grab sample bottle - Amber borosilicate or flint glass,
                T-liter or 1-quart volume, fitted with screw caps lined with
                TFE-fluorocarbon.  Aluminum foil may be substituted for TFE
                if the sample is not corrosive.  If amber bottles are not
                available, protect samples from light. The container 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) • Must incorporate glass sample
                containers for the collection of a minimum of 250 mL.
                Sample containers must be kept refrigerated at 4°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 must be thoroughly rinsed with
                methanol, followed by repeated rinsings with reagent 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 - 2000-mL, with TFE-fluorocarbon stopcock,
                ground glass or TFE stopper.

         5.2.2  Drying column - Chromatographic column 400 irni long x 19 ran
                ID with coarse fritted disc.

         5.2.3  Concentrator tube, Kuderna-Oanish - 10-mL, graduated (Kontes
                K-570050-1025 or equivalent).  Calibration must be checked
                at the volumes employed in the test.  Ground glass stopper
                1s used to prevent evaporation of extracts.

         5.2.4  Evaporative flask, Kudema-Oanish - 500-mL (Kontes
             •   K-570001-0500 or equivalent).  Attach to concentrator tube
                with springs.

         5.2.5  Snyder column, Kuderna-Oanish - three-ball macro (Kontes
                K-503000-0121 or equivalent).

-------
         5.2.6  Vials - Amber glass, 10 to 15 at capacity with
                TFE-fluorocarbon lined screw cap.

    5.3  Boiling chips - approximately 10/40 mesh. • Heat at 400°C for 30
         m1n or Soxhlet extract with methylene chloride.

    5.4  Water bath - Heated, with concentric ring cover, capable of temper-
         ature control (± 2°C).  The bath should be used 1n a hood.

    5.5  Balance - Analytical, capable of accurately weighing to the nearest
         0.0001 g.

    5.6-  Sas chroraatograph - Analytical system complete with gas chromato-
         graph suitable for on-column Injection and all required accessories
         Including syringes, analytical columns, gases, detector and strip-
         chart recorder.  A data system 1s recommended for measuring peak
         areas.

         5.6.1  Column 1 - 180 cm long x 2 mm ID glass, packed with 3<
                SP-22500B on Supelcoport (100/120 mesh) or equivalent.
                Operation of this column at high temperatures will seriously
                reduce Its useful period of performance.  This column was
                used to develop the method performance statements in Section
                15.  Alternative columns may be used In accordance with the
                provisions described in Section 12.1.

         5.6.2  Column 2 - 180 cm long x 2 mm ID glass, packed with 32
                SP-2401 on Supelcoport (100/120 mesh) or equivalent.

         5.6.3  Detector - Thermionic bead In the nitrogen mode.  This
                detector has proven effective 1n the analysis of wastewaters
                for the parameters listed In the scope and was used to
                develop the method performance statements In Section 15.
                Alternative detectors, Including a mass spectrometer, may be
                used in accordance with the provisions described in Section
                12.1.

6.  Reagents                                              _

    6.1  Reagent water - Reagent water 1s defined as a water in which an
         Interferent is not observed at the method detection limit of each
         parameter of Interest.

    6.2  Acetone, methy!ene chloride - Pesticide quality or equivalent.

    6.3  Sodium sulfate - (ACS) Granular, anhydrous.  Heat treat in a
         shallow tray at 400°C for a minimum of 4 n to remove phthalates
         and other Interfering organic substances.  Alternatively, heat 16 h
         at 450-500°C in a shallow tray or Soxhlet extract with methylene
         chloride for 48 h.

-------
    6.4  Stock standard solutions (1.00 yg/uU - Stock standard solutions
         may be prepared from pure standard materials or purchased as
         certified solutions.

         6.4.1  Prepare stock standard solutions by accurately weighing
                approximately 0.0100 g of pure material.  Dissolve the
                material in pesticide quality acetone and dilute to volume
                1n a 10-mL volumetric flask.  Larger volumes may be used at
                the convenience of the analyst.  If compound purity is
                certified at 96X or greater, the weight may be used without
                correction to calculate the concentration of the stock
                standard.  Commercially prepared stock standards may be used
                at any concentration if they are certified by the manufac-
                turer or by an independent source.

         6.4.2  Transfer the stock standard solutions into TFE-fluorocarbon-
                sealed screw cap vials.  Store at 4°C and protect from
                light.  Frequently check stock standard solutions for signs
                of degradation or evaporation, especially just prior to
                preparing calibration standards from them.

         6.4.3  Stock standard solutions must be replaced after six months
                or sooner if comparison with check standards indicates a
                problem.

7.  CalIbrati on

    7.1  Establish gas chromatographlc operating parameters equivalent to
         those Indicated in Table 1.  The gas chromatographic system may be
         calibrated using either the external standard technique (Section
         7.2) or the Internal standard technique (Section 7.3).

    7.2  External standard calibration procedure:

         7.2.1  For each parameter of interest, prepare calibration stan-
                dards at a minimum of three concentration levels by adding
                accurately measured volumes of one or more stock standards
                to a volumetric flask and diluting to volume with acetone.
                One of the external standards should be representative of a
                concentration near, but above, the method detection limit.
                The other concentrations should correspond to the range of
                concentrations expected in the sample concentrates or should
                define the working range of the detector.

         7.2.2  Using injections of 1 to 5 uL of each calibration standard,
                tabulate peak height or area responses  against the mass
                Injected.  The results can be used to prepare a calibration
                curve for each parameter.  Alternatively, the ratio of the
                response to the mass Injected, defined  as the calibration
                factor  (CF), may be calculated for each parameter at each
                standard concentration.  If the relative standard deviation

-------
            of the calibration factor is less than 101 over the working
            range, the average calibration factor can be used in place
            of a calibration curve.

     7.2.3  The working calibration curve or calibration factor must be
            verified on each working shift by the measurement of one or
            nore calibration standards.  If the response for any para-
            meter varies from the predicted response by more than ±10*,
            the test must be repeated using a fresh calibration stan-
            dard.  Alternatively, a new calibration curve or calibration
            factor must be prepared for that parameter.

7.3  Internal standard calibration procedure.  To use this approach, the
     analyst must select one or more internal standards similar in
     analytical behavior to the compounds of interest.  The analyst must
     further demonstrate that the measurement of the internal standard
     1s not affected by method or matrix interferences.  Due to these
     limitations, no internal standard applicable to all samples can be
     suggested.

     7.3.1  Prepare calibration standards at a minimum of three con-
            centration 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 acetone.  One of the standards should be
            representative of a concentration near, but above, the
            method detection limit.  The other concentrations should
            correspond to the range of concentrations expected 1n the
            sample concentrates, or should define the working range of
            the detector.

     7.3.2  Using injections of 1 to 5 uL of each calibration standard,
            tabulate the peak height or area responses against the
            concentration for each compound and Internal standard.
            Calculate response factors (RF) for each compound as follows:

                RF « (AsC1s)/(Ais Cs)

            where:
             •  AS  * Response for the parameter to be measured.
               A-fs * Response for the Internal standard.
               C-jS » Concentration of the Internal standard in ug/l.
               Cs  « Concentration of the parameter to be measured
                     in
            If the RF value over the working range 1s constant,  less
            than 10% relative standard deviation, the RF can be  assumed
            to be invariant and the average RF may be used for calcula-
            tions.  Alternatively, the results may be used to plot  a
            calibration curve of response ratios, As/A-js against RF.

-------
         7.3.3  The working calibration curve or RF must be verified on each
                working shift by the measurement of one or more calibration
                standards.  If the response for any parameter varies from
                the predicted response by more than ±102, the test must be
                repeated using a fresh calibration standard.  Alternatively,
                a new calibration curve must be prepared for that compound.

    7.4  Before using any cleanup procedure, the analyst oust process  a
         series of calibration standards through the procedure to validate
         elution patterns and the absence of interference from the reagents.

8.  Quality Control

    8.1  Each laboratory using 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
         the analysis of spiked samples as a continuing check on perfor-
         mance.  The laboratory is required to maintain performance records
         to define the quality of data that is generated.

         8.1.1  Before performing any analyses, the analyst must demonstrate
                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 the rapid advances occurring in chroraato-
                graphy, the analyst is permitted certain options to improve
                the separations or lower the cost of measurements.  Each
                time such modifications to the method are made, the analyst
                1s required to repeat the procedure 1n Section 8.2.

         3.1.3  The laboratory must spike and analyze a minimum of 102 of
                all samples to monitor continuing laboratory performance.
                This procedure 1s described in Section 8.4.

    8.2  To establish the ability to generate acceptable accuracy and
         precision, the analyst must perform the following operations.

         8.2.1  Select a representative spike concentration for each
                compound to be measured.  Using stock standards, prepare a
                quality control check sample concentrate in acetone 1000
                times more concentrated than the selected concentrations.

         8.2.2  Using a pipet, add 1.00 mL of the check sample concentrate
                to each of a minimum of four 1000-mL aliquots of reagent
                water. A representative wastewater may be used in place of
                the reagent water, but one or more additional aliquots must
                be analyzed to determine background levels, and the spike
                level must exceed twice the background level for the test to
                be valid.  Analyze the aliquots according to the method
                beginning in Section 10.

-------
     8.2.3  Calculate the average percent recovery  (R),  and  the  standard
            deviation of the percent recovery  (s),  for the results.
            Wastewater background corrections  must  be made before R  and
            s calculations are performed.

     3.2.4  Using the appropriate data from Table 2, determine the
            recovery and single operator precision  expected  for  the
            method, and compare these results  to the values  calculated
            1n Section 8.2.3.  If the data are not  comparable, review
            potential problem areas and repeat the  test.

8.3  The analyst must calculate method performance  criteria  and  define
     the performance of the laboratory for each spike concentration  and
     parameter being measured.

     8.3.1  Calculate upper and lower control  limits for method  perfor-
            mance as follows:

               Upper Control Limit (UCL) » R + 3 s
               Lower Control Limit (LCL) ' R - 3 s

            where S and s are calculated as 1n Section 8.2.3.
            The UCL and LCL can be used to construct control charts6
            that are useful 1n observing trends 1n  performance.

     8.3.2  The laboratory must develop and maintain separate accuracy
            statements of laboratory performance for wastewater  samples.
            An accuracy statement for the method 1s defined  as R ± s.
            The accuracy statement should be developed by the analysis
            of four aliquots of wastewater as  described  in Section
            8.2.2, followed by the calculation of R and  s.   Alterna-
            tlvely.the analyst may use four wastewater data  points
            gathered through the requirement for continuing  quality
            control 1n Section 8.4.  The accuracy statements should  be
            updated regularly.6

8.4  The laboratory 1s required to collect in  duplicate  a portion of
     their samples to monitor spike recoveries.  The frequency of spiked
     sample analysis must be at least 102 of all samples or  one  spiked
     sample per month, whichever 1s greater.   One aliquot of the sample
     must be spiked and analyzed as described  in Section 8.2.  If the
     recovery for a particular parameter does  not fall within the
     control limits for method performance, the results reported for
     that parameter in all samples processed as part of the  same set
     must be qualified as described 1n Section 13.3.  The laboratory
     should monitor the frequency of data so qualified to ensure that 1t
     remains at or below 5X.

8.5  Before processing any samples, the analyst must demonstrate through
     the analysis of a 1-liter aliquot of reagent water that all
     glassware and reagents interferences are  under control.  Each time
     a set of samples is extracted or there is a change  in reagents, a

                                   8

-------
         laboratory reagent blank must be processed as a safeguard  against
         laboratory contamination.

    8.6  It 1s recommended that the laboratory adopt additional quality
         assurance practices for use with thfs 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 monitor the precision of the sampling technique.  When
         doubt exists over the identification of a peak on the chromatogram,
         confirmatory techniques such as gas chromatography with a  dissim-
         ilar column, specific element detector, or mass spectrometer roust
         be used.  Whenever possible, the laboratory should perform analysis
         of quality control materials and participate in relevant perfor-
         mance evaluation studies.

9.  Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers.  Conventional
         sampling practices7 should be followed; however, 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 plastic and other potential sources
         of contamination.

    9.2  The samples must be iced or refrigerated at 4°C from the time of'
         collection until extraction.

    9.3  All samples must be extracted within seven days and completely •
         analyzed within 40 days of extraction.

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-liter separatory funnel.

    10.2 Add 60 mi. methylene chloride to the sample bottle, seal, and shake
         30 s to rinse the inner walls.  Transfer the solvent to the separa-
         tory 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
         rain.  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 opti-
         mum technique depends upon the sample, but may include stirring,
         filtration of the emulsion through glass wool, centrlfugation, 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-0) concentrator by attaching a 10-mL
         concentrator  tube to a 500-mL evaporative flask.  Other concentra-
         tion devices  or techniques may be used in place of the K-0 if the
         requirements  of Section 8.2 are met.

    10.5  Pour the combined extract through a drying column containing about
         10  on of anhydrous sodium sulfate, and collect the extract in the
         K-0 concentrator.  Rinse the Erlenmeyer flask and column with 20 to
         30  roL of methylene 'chloride to complete the quantitative transfer.

    10.6  Add 1 or 2 clean boiling chips to the evaporative flask and attach
         a three-ball  Snyder column.  Prewet the Snyder column by adding
         about 1 mL methylene chloride to the top.  Place the K-D apparatus
         on  a hot water bath, 60 to 65°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-0 apparatus and allow
         1t  to drain and cool for at least 10 rain.

    10.7  Increase the temperature of the hot water bath to about 70°C.
         Momentarily remove the Snyder column, add 50 mL of acetone and a
         new boiling chip and reattach the Snyder column.  Pour about 1 mL
         of  acetone into the top of the Snyder column and concentrate the
         solvent extract as before.  Elapsed time of concentration shou-ld be
         5 to 10 min.  When the apparent volume of liquid reaches 1 mL,
         remove the K-0 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 hexane and adjust the
         volume to 10 mL.  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 extracts will
         be  stored longer than two days, they should be transferred to
         TFE-fluorocarbon-sealed screw-cap vials.  Analyze by gas chromato-
         graphy.

    10.9  Determine the original sample volume by refilling the sample bottle
         to  the mark and transferring the water 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

                                      10

-------
         cleanup procedure, the analyst must determine the elutlon profile
         and demonstrate that the recovery of each compound of Interest for
         the cleanup procedure 1s no less than 852.

12. Sas Chromatography

    12.1 Table 1 summarizes the recommended operating conditions for the gas
         chromatograph.  Included 1n this table are estimated retention
         times and method detection limits that can be achieved by this
         method.  An example of the separations achieved by Column 1 1s
         shown 1n Figure 1.  Other packed columns, chromatographic condi-
         tions, or detectors may be used if the requirements of Section 8.2
         are met.  Capillary (open-tubular) columns may also be used if the
         relative standard deviations of responses for replicate injections
         are demonstrated to be less than 6% and the requirements of Section
         8.2 are met.

    12.2 Calibrate the system dally as described 1n Section 7.

    12.3 If the Internal standard approach is being used, add the internal
         standard to sample extracts immediately before injection into the
         Instrument.  Mix thoroughly.

    12.4 Inject 1 to 5 uL of the sample extract using the solvent-flush
         technique.8  Record the volume injected to the nearest 0.05 yL,
         and the resulting peak size In area or peak height units.  An
     2   automated system that consistently injects a constant volume of
         extract may also be used.

    12.5 The width of the retention time window used to make identifications
         should be based upon measurements of actual retention time varia-
         tions of standards over the course of a day.  Three times the
         standard deviation of a retention time can be used to calculate a
         suggested window size for a compound.  However, the experience of
         the analyst should weigh heavily in the Interpretation of chromato-
         graras.

    12.6 If the response for the 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, cleanup 1s 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
                in Section 7.2.2.  The concentration in the sample can be
                calculated as follows:

                                      11

-------
                                                     (A)(Vt)
                          Concentration, ug/L  *  —nj
                where:
                   A   « Amount of material Injected, in nanograms.
                   V-j  » Volume of extract injected In uL.
                   V^  » Volume of total extract in uL.
                   Vs  « Volume of water extracted in mL.

         13.1.2 If the  internal standard calibration procedure was used,
                calculate the concentration in the sample using the response
                factor  (RF) determined 1n Section 7.3.2 as follows:

                                                   (AJCI.)
                        Concentration, ug/l  *  (A1s)(RF)(VQ)

                where:
                   A;  • Response for the parameter to be measured.
                   A-JS  » Response for the internal standard.
                   Is  * Amount of internal standard added to each
                         extract in ug.
                   V0  « Volume of water extracted, in liters.

    13.2 Report results in micrograms per liter without correction for
         recovery data.  When duplicate and spiked samples are analyzed,
         report all data obtained with the sample results.

    13.3 For samples processed as part of a set where the laboratory spiked
         sample recovery falls outside of the control limits in Section 3.3,
         data for the affected parameters must be labeled as suspect.

14. 6C/MS Confirmation

    14.1 It is recommended that SC/MS techniques be judiciously employed to
         support qualitative compound identifications made with this
         method.  The mass spectrometer should be capable of scanning the
         mass range from 35 amu to a mass 50 amu above the molecular weight
         of the compound.  The instrument must be capable of scanning the
         mass range at  a rate to produce at least 5 scans per peak but not
         to exceed 7 s  per scan utilizing a 70 V (nominal) electron energy
         in the electron impact 1on1zat1on mode.  A SC to MS interface
         constructed of all-glass or glass-lined materials 1s recommended.
         A computer system should be interfaced to the mass spectrometer
         that allows the continuous acquisition and storage on machine
         readable media of all mass spectra obtained throughout the duration
         of the chromatographic program.

    14.2 Gas chroraatographic columns and conditions should be selected for
         optimum separation and performance.  The conditions selected must
         be compatible  with standard SC/MS operating practices.  Chromato-
         graphic tailing factors of less than 5.0 must be achieved.9


                                      12

-------
    14.3  At the beginning  of  each day that confirmatory analyses are to be
         performed,  the  GC/MS system must be checked to see that all
         decaf luorgtriphenyl  phosphlne (DFTPP)  performance criteria are
         achieved.10

    14.4  To confirm  an identification of a compound, the background
         corrected mass  spectrum of the compound must be obtained from the
         sample extract  and compared with a mass spectrum from a- stock or
         calibration standard analyzed under the same chromatographic
         conditions. It is recommended that at least 25 nanograms of
         material be injected into the GC/MS.  The criteria below must be
         met for qualitative  confirmation.

         14.4.1 All  ions that are present above 10* relative abundance in
                the  mass spectrum of the standard must be present in the
                mass spectrum of the sample with agreement to plus or minus
                lOt. For example, if the relative abundance of an ion is
                30%  in the mass spectrum of the standard, the allowable
                limits for the relative abundance of that ion in the mass
                spectrum for  the sample would be 202 to 401.

         14.4.2 The  retention time of the compound in the sample must be
                within 6 seconds of the same compound in the standard
                solution.

         14.4.3 Compounds that have very similar mass spectra can be
                explicitly identified by SC/MS only on the basis of
                retention time data.

 -  14.5  Where available,  chemical ionization mass spectra may be employed
         to aid in the qualitative identification process.

    14.6  Should these MS procedures fail to provide satisfactory results,
         additional  steps may be taken before reanalysis.  These may Include
         the use of  alternate packed or capillary GC columns or additional
         cleanup (Section 11).

IS. Method Performance                                     _____

    15.1  The method  detection limit (MOL) is defined as the minimum concen-
         tration of  a substance that can be measured and reported with 99*
         confidence  that the  value is above zero.11  The MOL
         concentrations  listed in Table 1 were obtained using reagent
         water
    15.2 In a single laboratory (West Cost Technical Services, Inc.), using
         effluents from pesticide manufacturers and publicly owned treatment
         works (POTW), the average recoveries presented in Table 2 were
         obtained.1  The standard deviations of the percent recoveries of
         these measurements are also included in Table 2.
                                      13

-------
References

T.  "Pesticide Methods Evaluation," Letter Reports #6, 12A and 14 for EPA
    Contract No. 68-03-2597.  Available from U.S. Environmental  Protection
    Agency, Environmental Monitoring and Support Laboratory,  Cincinnati,
    Ohio 45263.

2.  ASTM Annual Book of Standards, Part 31, 03694, 'Standard  Practice for
    Preparation of Sample Containers and for Preservation, "  American
    Society for Testing and Materials, Philadelphia, PA, p. 679, 1980.

3.  "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, Aug. 1977.

4.  "OSHA Safety and Health Standards, General Industry,' (29 CFR 1910),
    Occupational Safety and Health Administration, OSHA 2206, (Revised,
    January 1976).

5.  "Safety in Academic Chemistry Laboratories," American Chemical Society
    Publication, Committee on Chemical Safety, 3rd Edition, 1979.

6.  "Handbook for Analytical Quality Control in Water and Wastewater
    Laboratories," EPA-600/4-79-019, U. S. Environmental Protection Agency,
    Environmental Monitoring and Support Laboratory - Cincinnati, Ohio
    45268, March 1979.

7.  ASTM Annual Book of Standards, Part 31, D3370, "Standard  Practice for
    Sampling Water,"  American Society for Testing and Materials,
    Philadelphia, PA, p. 76, 1980.

8.  Burke, J. A., "Sas Chromatography for Pesticide Residue Analysis; Some
    Practical Aspects," Journal of the Association of Official Analytical
   "Chemists, 48, 1037 (1965).\

9.  McNalr, H.M. and BoneTH, E. J., "Basic Chromatography,"  Consolidated
    Printing, Berkeley, California, p. 52, 1969.

10. Elchelberger, J.W., Harris, L.E., and Budde, W.L. "Reference Compound to
    Calibrate Ion Abundance Measurement 1n Sas Chromatography-Mass
    Spectrometry," Analytical Chemistry, 47, 995  (1975).

11. Slaser, J.A. et.al, "Trace Analysis for Wastewaters," Environmental
    Science & Technology, J5_, 1426 (1981).	..   _
                                      14

-------
                                    TABLE 1

            CHROMATOGRAPHIC CONDITIONS AND METHOD DETECTION LIMITS
Parameter
Terbacll
Bromacll
Hex ari none
Trfcyclazole
Metribuzin
Tr1ad1raefon
Oeet
ec
Column
la
la
Ta
Ib
2a
2a
2b
Retention
Time
(M1n)
2.1
3.7
7.6
3.5
2.4
4.1
4.6
Method
Detection Limit
(ug/L)
NO
2.38
0.72
NO
0.46
0.78
3.39
ND * Not determined

Column la conditions:  Supelcoport (100/120 mesh) coated with 3% SP-2250D8
packed in a 180 cm long x 2 mm ID glass column with nitrogen carrier gas at
a flow rate of 30 mL/m1n.  Column temperature, programmed: Initial 210°C,
hold for 1 rain, then program at 10°C to 2SO°C and hold.  A thermionic
bead detector in the nitrogen mode was used to calculate the MOL.

Column Ib conditions:  Same as Column la, except column temperature
Isothermal at 240°C.

Column 2a conditions:  Supelcoport (100/120 mesh) coated with 32 SP-2401
packed in a 180 on long x 2 mm ID glass column with nitrogen carrier gas at
a flow rate of 30 mL/m1n.  Column temperature, programmed: initial 160°C,
programmed at injection at 10°C/min to 230°C.

Column 2b conditions:  Same as Column 2a, except temperature programed:
Initial 130°C, hold for 1 min, then program at 12°C/min to 200°C.
                                      T5

-------
                                    TABLE  2

                    SINGLE OPERATOR ACCURACY AND PRECISION
Parameter
BromacH


Oeet


Hexazlnon


Metrlbuzin
TerbacH

Trladmefon


Tricyclazole

Sample
Type
OW
MW
MW
OW
MW
MW
OW
MW
MW
OW
MW
MW
OW
PW
IW
MW
MW
Spike
(ug/L)
5
11.1
333
5.3
5.2
515
4.9
10.1
369
5.2
32.8
656
5.2
515
154.5
12.3
303
Number
of
Replicates
7
7
7
7
7
7
7
7
7
6
7
7
6
4
7
7
7
Mean
Recovery
(X)
92.2
89
95
99.1
92.6
94.2
86.6
92.2
94.0
98.2
106.7
101
126
71.8
70.4
69
98
Standard .
Deviation
(X)
13.9
3.9
0.3
18.4
5.9
2.2
4.1
5.3
1.9
2.7
3.6
1.2
6.0
4.5
3.3
1.9
1.2
DW * Reagent water
MW * Municipal wastewater
PW * Process water, pesticide manufacturing
IW • Industrial wastewater, pesticide manufacturing
                                     16

-------
                  Terbadl
                                               Hexazinone
                                 t
                                4     5

                                Minutes
8
Figure 1.  Gas chromatogram of organonitrogen pesticides on Column 1
           For conditions,  s.ee Table  1.
                                   17

-------