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SOP 39, Rev. 4 Page 2 of 30
Vista Analytical Laboratory El Dorado Hills, CA 95762
1. PURPOSE 1.1. This procedure describes the preparation and analytical techniques used for
the analysis of samples for pesticides by EPA Method 1699.
2. SCOPE 2.1. This method is for the determination of the pesticides at the quantitation limits
listed in Table 1 for water, soil, sediment, and sludge by gas chromatography/high resolution mass spectrometry/selective ion monitoring (GC/HRMS/SIM).
2.2. All differences between Method 1699 and actual laboratory techniques have been developed to reduce interferences and increase sensitivity.
2.3. Data determined to be out-of-control from criteria stated within this SOP, is handled according to procedures addressed within the applicable section.
2.4. The reporting limits and quantitation levels are usually dependent on the level of interferences rather than instrumental limitations. The quantitation limits listed are levels at which the Pesticides can be determined with only common laboratory interferences present.
2.5. Detection limits are sample-specific and congener-specific.
3. METHOD MODIFICATIONS 3.1. This method is "performance-based". Modifications to the method to
overcome interferences or lower the cost of measurements are permitted, provided that all performance criteria in this method are met.
3.2. The following modifications to the method were made to improve efficiency and accuracy:
3.2.1. Aqueous samples are extracted with 3 x 60 mL DCM instead of 3 x 100 mL DCM.
3.2.2. Additional internal standards have been added to improve quantitation. These compounds include: 13C12-alpha-BHC, 13C12-2,4’-DDE, 13C12-2,4’-DDD, 13C12-4,4’-DDD, 13C12-Endosulfan sulfate, 13C12-Methoxychlor, 13C12-Endrin aldehyde, and 13C12-Endrin ketone.
3.2.3. Compounds such as Aldrin and Mirex have shown signal suppression with toluene/SDS extraction in certain matrices. Experimental extractions with actual matrix will be performed with DCM, Toluene, and 70:30 Hexane:Ethyl acetate to determine optimal extraction solvent.
3.2.4. Toluene is not added as a keeper during rotovap evaporation.
3.2.5. Neither CLLE nor SPE are used for aqueous extractions.
3.2.6. Cleanups are accomplished with a combination of silica gels and Carbon on Florisil for solids, and only silica gel for aqueous matrices.
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3.2.7. DCM has been substituted for ethyl ether in Florisil elution for safety reasons.
3.2.8. GPC, HPLC, and SPE are not currently used for cleanup.
4. DEFINTIONS 4.1. Definitions are presented in Glossary.
5. CONTAMINATION AND INTERFERENCES 5.1. All materials used in the analysis shall be demonstrated to be free from
interferences by running reference matrix method blanks with each sample batch.
5.2. The reference matrix should simulate, as closely as possible, the sample matrix under test. Reagent water can be used to simulate water samples; Ottawa sand can be used to simulate soils.
5.3. Interferences coextracted from samples will vary from source to source, depending on the site being sampled. The cleanup steps can be used to reduce or eliminate such interferences.
6. SAFETY 6.1. Procedures shall be carried out in a manner that protects the health and safety
of all Vista employees, including the appropriate use of Personal Protective Equipment and engineering controls.
6.2. Each chemical compound should be treated as a potential health hazard. Exposure to these compounds should be reduced to the lowest possible level. Only highly trained personnel thoroughly familiar with handling and cautionary procedures and the associated risks should handle all compounds or reagents.
6.3. Each chemical compound should be handled in well-ventilated, controlled access laboratories.
6.4. Additional health and safety information can be obtained from material safety data sheets (MSDSs) available to all personnel involved in these analyses.
6.5. In the event of a known or potential compromise to the health and safety of a Vista associate, all work must stop and the incident reported immediately to management.
7. APPARATUS AND MATERIALS 7.1. Amber glass bottles, 1 liter & 500 mL (Teflon-lined screw cap)
7.2. Analytical Balance, capable of reading to 0.0001 g
7.3. Aquacheck and pH strips
7.4. Compaq Personal Work Station 433/500
7.5. Neslab HX200 and HX500 Water Cooler
7.6. Micromass Autospec Ultima High Resolution Mass Spectrometer (M390, M467, M504, M529, M651)
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7.7. Hewlett Packard 6890 Gas Chromatograph
7.8. CTC Autosampler Model A200S
7.9. ZB-50 (or equivalent) column
7.10. Drying oven, VWR Model 1320 or equivalent
7.11. Glass columns
7.12. Glass wool
7.13. Organomation 24-Station N-Evaporator
7.14. Precleaned Glass fiber thimbles - coarse
7.15. Rotary evaporator
7.16. Round bottom flasks: 50, 100, 250, and 500 mL
7.17. Separatory funnels, typically 250 mL to 2-L size
7.18. Soxhlet/Dean-Stark (SDS) Extractor
7.19. Teflon boiling chips
7.20. Test tubes plus Teflon lined caps, 16 mm x 125 mm
7.21. Whatman GF/C, GF/D, and GF/F filters
8. REAGENTS, SOLVENTS AND STANDARDS 8.1. Reagents (Highest purity available)
8.1.1. Activated Silica Gel, for ~5 hours at 550°C
8.1.2. Anhydrous sodium sulfate (Na2SO4), kilned for ~5 hours at 550°C, granular
8.1.3. Hydromatrix
8.1.4. CarbonX on Florisil, United Science
8.1.5. Florisil
8.1.6. Ottawa sand, kilned for ~5 hours at 550°C
8.1.7. Sodium hydroxide, 10N
8.1.8. Sulfuric acid, concentrated
8.1.9. Ultra-pure nitrogen gas
8.1.10. Water, HPLC
8.2. Solvents (Highest purity available)
8.2.1. Acetone
8.2.2. Ethanol
8.2.3. Hexane
8.2.4. Methanol
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8.2.5. Methylene chloride (DCM)
8.2.6. Nonane
8.2.7. Toluene
8.3. Standards
8.3.1. All analytical standards are obtained from a certified vendor.
8.3.2. See current spike sheet for spiking concentrations and solutions.
8.4. See SOP 15 for preparation of reagents, standards and documentation.
9. SAMPLE COLLECTION, PRESERVATION, STORAGE AND HOLDING TIMES 9.1. Aqueous: Extract within 7 days and analyze within 40 days of extraction
9.2. Soil/sediments
9.2.1. Percent solids must be determined within 14 days of collection.
9.2.2. Extract and analyze within one year from collection. If the sample is extracted after 14 days of collection, the % solids must be determined again.
9.3. Store samples at 4°C. Store extracts at <-10oC in the dark.
9.4. If residual chlorine is detected in an aqueous sample, add 80 mg sodium thiosulfate per liter.
10. SAMPLE PREPARATION 10.1. Residual Chlorine Determination (aqueous only)
10.1.1. Obtain an Aquacheck strip and place it directly into a small amount of sample in a disposable weigh boat. Move the strip back and forth for 30 seconds.
10.1.2. Check the color on the strip against the color chart on Aquacheck container.
10.1.3. If there is chlorine present, add 80 mg of sodium thiosulfate.
10.1.4. Record procedure on extraction benchsheet.
10.2. pH Determination (aqueous only)
10.2.1. Obtain a pH strip and place it directly into a small amount of sample in a disposable weigh boat. Move the strip back and forth for 30 seconds.
10.2.2. Check the color on the strip against the color chart on the pH container. Adjust the pH to 5-9 with sulfuric acid or sodium hydroxide, if necessary.
10.3. % Solids Determination
10.3.1. “ZERO” or “TARE” the balance.
10.3.2. Place a weigh boat on the balance and record the weight as “Boat
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Weight”.
10.3.3. Samples are individually homogenized with a clean spoon, spoonula or spatula. Add a portion of the sample (2 – 10 g) to the weigh boat and record the weight as “Wet Wt. + Boat Wt.”
10.3.4. Place the weigh boat plus sample in an oven at 110±5°C for at least overnight.
10.3.5. Remove the weigh boat plus sample from the oven and allow to come to room temperature.
10.3.6. “ZERO” or “TARE” the balance.
10.3.7. Place the weigh boat plus sample on the balance and record the weight as “Residue + Boat Wt.”
10.3.8. Calculate the percent solids by the following formula:
( ) ( )( ) ( ) 100 X
Wt.Boat Wt.Boat Wt.Wet Wt.Boat Wt.Boat Wt.Residue%Solids
−+−+
=
10.3.9. For aqueous samples, if %Solid exceeds 1%, remove any rocks or stones and homogenize the sample prior to extraction. Weigh 10 grams dry-weight equivalent for extraction.
10.4. Compositing – by client request
10.4.1. Samples are individually homogenized, if necessary, with a clean spoon, spoonula or spatula. Aqueous samples should be mixed and shaken to obtain a representative sample.
10.4.2. Weigh out approximately 50 grams, or amount designated by the client, from each individual sample and place into a pan.
10.4.3. Repeat the homogenization for each sample.
10.4.4. Place each individual sample into a new, separate container. Record the weight of each sample on the benchsheet.
10.4.5. Retain the original sample containers. The new container is given a new sample ID number and then processed through the appropriate extraction.
10.5. Sample Weight Determination
10.5.1. Volumetric: Allow sample to come to ambient temperature, mark the water meniscus on the side of the 1 L sample bottle. Once the sample has been transferred, fill the sample bottle to the mark with water and transfer to a 1000 mL graduated cylinder. Record the sample volume to the nearest 5 mL.
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10.5.2. Gravimetric: Sample bottle including sample is placed on calibrated balance. The weight is recorded. The bottle is allowed to air-dry overnight and then re-weighed on a calibrated balance. This weight is recorded and percent solids are determined.
11. EXTRACTION PROCEDURES
11.1. Aqueous Samples
11.1.1. Record the combined weight of the bottle, cap and sample for each sample to be extracted. After the sample has been removed from the bottle, allow it to drain overnight and reweigh it and the cap to determine the amount of sample extracted.
11.1.2. For the method blank (MB) and OPR(s), transfer ~1 liter of HPLC water into a one liter bottle for each.
Add the appropriate volume of Internal Standard (IS) solution to a test tube containing ~1 mL of acetone. Quantitatively transfer to the aliquot of matrix with small portions of the solvent used. Add the appropriate volume of Native Standard (NS) solution to a test tube containing the IS/solvent and then quantitatively transfer to the aliquot of matrix assigned as an LCS, OPR, MS or MSD. Allow the spiked samples to equilibrate for at least 1 hour before extraction.
11.1.3. Pour the sample into a 2-liter separatory funnel. Rinse the sample container with ~60 mL of DCM and add it to the separatory funnel.
11.1.4. Stopper each separatory funnel and shake vigorously, with frequent venting, for 2 minutes.
11.1.5. Allow the phases to separate (centrifugation or other mechanical means may be used to facilitate separation).
11.1.6. Drain the DCM extract through a funnel of Na2SO4 into a 500 mL round bottom flask.
11.1.7. Extract the aqueous phase with two more ~60 mL portions of DCM (shaking 2 minutes each time) and pass the extracts through the Na2SO4 into the round bottom containing the first extract.
11.1.8. Concentrate the extract to approximately 10 mLs.
11.2. Soil, Sediment, Solids, Clay: 70:30 Hexane/Ethyl Acetate
11.2.1. Samples are individually homogenized with a clean spoon, spoonula or spatula. Weigh the sample (nominal 10 g dry weight equivalent) directly into an analyte-free thimble, carefully breaking up any large lumps of sample.
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o Add the appropriate volume of IS to all samples and NS solutions (OPR, MS or MSD) directly to the aliquot of matrix.
11.2.2. Assemble the SDS apparatus, and add a fresh charge of solvent to the receiver and reflux flask. Apply power to the heating mantle to begin refluxing. Adjust the reflux rate to match the rate of percolation until water removal lessens the restriction to solvent flow. Wrap soxhlet with bubble foil to increase temperature.
11.2.3. Reflux the sample for a total of 16-24 hours. Cool and disassemble the apparatus.
11.2.4. Remove the distilling flask. Drain the water from the Dean-Stark receiver.
11.2.5. Concentrate the extracts from the particles to approximately 5 mL using the rotary evaporator.
11.3. Sludge Samples
11.3.1. Weigh the sample (nominal 5 g dry weight equivalent) directly into an analyte free thimble.
Place a ball of glass wool at the bottom of the thimble and the soxhlet.
11.3.2. Add the appropriate volume of IS to all samples and NS solutions (OPR, MS or MSD) directly to the aliquot of matrix.
11.3.3. SDS extract for 16 hours with toluene/acetone.
11.3.4. If % solids are too low to accommodate a 10 g sample size into thimble, fill thimble half full of Hydromatrix.
11.3.5. Tare weight of thimble then fill thimble full of sludge.
11.3.6. Record weight of sludge, spike and then transfer immediately to soxhlet.
11.4. Soil, Sediment, Solids, Clay, Sludge Samples: Optional DCM/sox SDS, or 70:30 Hexane/Ethyl Acetate extraction.
11.4.1. Some samples have shown signal suppression with toluene extraction. If encountered, an optional DCM/soxhlet or 70:30 Hexane/Ethyl acetate extraction will replace the extraction solvent for soils/sludge.
11.4.2. Record weight of sample, spike and then transfer immediately to soxhlet as in the soil/sludge sections.
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11.4.3. Assemble the soxhlet or SDS apparatus, and add a fresh charge of the correct solvent to the receiver and reflux flask. Apply power to the heating mantle to begin refluxing. Reflux for 16-24 hours. Cool and disassemble the apparatus.
11.4.4. Concentrate the extracts from the particles to approximately 5 mL using the rotary evaporator.
12. CLEANUP PROCEDURES 12.1. Using a rotary evaporator; roto-evap to the ~2mL, add 50 – 100 mL of hexane
and roto-evap to ~2mL. Repeat once
12.2. Proceed to the appropriate cleanup.
12.3. Aqueous samples: Base Silica Gel column (BSG)
12.3.1. Prepare the column as depicted in Figure 1.
12.3.2. All traces of solvents other than hexane must be removed from the extract.
12.3.3. Adjust extract volume to <2 mL.
12.3.4. Rinse the BSG column with ~35 mL DCM followed by ~ 50mL hexane, discard the eluates.
12.3.5. Transfer the extract to the column with 2-4 small portions of hexane. Collect eluate.
12.3.6. Elute in order with 50 mL Hexane, 50 mL 20% DCM in Hexane, 50 mL 1:1 DCM/Hexane, collect.
12.3.7. Concentrate the eluate appropriately.
12.4. Solid and Tissue samples: 250mm Base Silica Gel Column
12.4.1. Prepare the column as depicted in Figure 2.
12.4.2. All traces of solvents other than hexane must be removed from the extract.
12.4.3. Adjust extract volume to <2 mL.
12.4.4. Rinse the BSG column with ~75 mL DCM followed by ~100mL hexane, discard the eluates.
12.4.5. Transfer the extract to the column with 2-4 small portions of hexane. Collect eluate.
12.4.6. Elute in order with 160 mL Hexane, 160 mL 20% DCM in Hexane, 280 mL 1:1 DCM/Hexane, collect.
12.4.7. Concentrate the eluate appropriately.
12.5. CarbonX on Florisil Column (COF)
12.5.1. Prepare the column as depicted in Figure 3.
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12.5.2. All traces of solvents other than hexane must be removed from the extract.
12.5.3. Adjust extract volume to <2 mL.
12.5.4. Rinse the COF column in order with ~10 mL Toluene, ~10mL DCM and ~10mL 90/10 Hexane/Acetone, discard the eluates.
12.5.5. Transfer the extract to the column with 2-4 small portions of hexane. Collect eluate.
12.5.6. Elute column with 35 mL 90/10 Hexane/Acetone, collect eluate.
12.5.7. Concentrate the eluate appropriately.
13. ADJUST TO FINAL VOLUME 13.1. Using hexane, quantitatively transfer the concentrated eluate to a conical vial
that contains ~20 µL of nonane.
13.2. Using nitrogen blow down, concentrate to ~50uL. Add ~20uL nonane.
13.3. Add recovery standard (RS). Concentrate to 20uL nonane
13.4. Using a 10-20 µL Wiretrol, transfer the extract to an insert in a crimp top autoinjector vial and then cap.
14. QUALITY CONTROL 14.1. Method Blank (MB): Method Blank is a matrix preparation that is free from
native analyte that has been prepared and analyzed using the same procedures followed for the rest of the sample batch. HPLC water is used for aqueous samples, sand is used for solid and fish samples.
14.1.1. A MB is run with every analytical batch or 20 samples, whichever is less, per matrix type.
14.1.2. Analyze the method or solvent blank immediately after analysis of the OPR to demonstrate freedom from contamination.
14.1.3. If the amount found is greater than the minimum level or one-third the regulatory compliance limit, whichever is greater; or if any potentially interfering compound is found in the blank at or above the minimum level for each congener, the data must be evaluated to determine whether the batch shall be re-extracted or the data is qualified appropriately.
14.2. Ongoing Precision and Recovery (OPR): An ongoing precision and recovery sample is prepared by adding a known quantity of native standard to an interferant free matrix and used to assess method performance (precision and recovery).
14.2.1. Spike 10 µL of compound spiking solution into the sample.
14.2.2. An OPR is analyzed with every analytical batch or 20 samples (whichever is less) per matrix type.
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14.2.3. For each native and labeled compound, compare the concentration with the limits for ongoing accuracy in Table 5. If all compounds do not meet acceptance criteria, re-extract and analyze the batch.
14.3. Matrix Spike (MS/MSD): A matrix spike sample is prepared by adding a known quantity of native standard to a sample matrix prior to extraction.
14.3.1. Matrix Spikes are performed by client request.
Note: Projects performed pursuant to the guidelines established by the DoD QSM shall contain an associated Matrix Spike per preparatory batch. A Matrix Spike Duplicate or Laboratory Duplicate shall also be analyzed per preparatory batch for these projects.
14.3.2. Spike 10 µL of compound spiking solution into the sample.
14.3.3. The relative percent difference between MS/MSD samples should be ≤20%. If the criteria are not met, the data must be evaluated to determine whether the samples shall be re-extracted or the data are qualified appropriately
14.4. Duplicate Samples: Duplicate samples are two separate aliquots taken from the same source. Duplicate samples are analyzed independently to assess laboratory precision. Duplicate samples are performed by client request.
14.4.1. If the relative percent difference from duplicate sample analyses is greater than 50%, then both duplicate samples will be flagged.
14.4.2. Criteria for qualitative and quantitative determinations of chromatographic peaks must be met.
15. HRMS ANALYSIS 15.1. Establish the necessary operating conditions. The GC conditions may be
optimized for compound separation and sensitivity. Once optimized, the same GC conditions must be used for the analysis of all standards, blanks, OPR aliquots and samples. The following GC operating conditions are for guidance and adjustments may be required.
Injector temperature: 270°C Interface temperature: 290°C Initial temperature: 130°C Initial time: 1.0 minutes Temperature program: 130 - 200°C at 5°C/min
200°C for 16 minutes 200 - 280°C at 8°C/min 280°C for 11 minutes 280 - 300°C at 13°C/min 300°C for 4.5 minutes
15.2. GC Column
15.2.1. The retention time for methoxychlor must exceed 39 minutes.
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15.2.2. trans-Chlordane and trans-nonachlor must be uniquely resolved to a valley height less than 10 percent of the shorter of the two peaks.
15.3. Instrument Tuning
15.3.1. Inject the reference compound perfluorokerosene (PFK) performed at the beginning and at the end of each shift. PFK provides the required lock masses and is used for tuning the mass spectrometer.
15.3.2. Using a PFK molecular leak, tune the instrument to meet the minimum required resolving power of 6,000 – 8,000 at or close to m/z 304.9824. Resolution must be >6,000 throughout the mass range and must be 8,000 in the center of the mass range for each function.
15.3.3. An appropriate lock mass will be monitored for each descriptor and shall not vary by more than ± 20% throughout the respective retention time window.
15.3.4. For the measurement of pesticides, the exact m/zs to be monitored in each descriptor are listed in Table 4.
15.4. Initial Calibration
15.4.1. Under the same conditions, inject 1-2 µL of each of the six calibration solutions containing all pesticide analytes. Calibration standard solutions are presented in Table 2.
15.4.2. Twenty-eight internal standards and six recovery standards are used to improve quantitation. Internal standards may be quantified off alternate recovery standards if interferences occur.
15.4.3. Verify that the HRGC/HRMS instrument meets the minimum levels (MLs) in Table 1. The peaks representing the pesticides and labeled compounds in the CS1 calibration standard must have signal-to-noise ratios (S/N) that exceed 3:1.
15.4.4. The ion abundance ratio measurements must be within the limits in Table 3.
15.4.5. Calibration by Isotope Dilution: Isotope dilution calibration is used for the native pesticides for which labeled compounds are added to samples prior to extraction.
15.4.6. If the relative response for any native compound is less than 20% RSD (or 35% for labeled compounds) over the 6-point calibration range, an averaged relative response is used for that compound. In addition, the low point of the curve may be dropped and reporting limit adjusted accordingly, if necessary.
15.4.7. Perform the Endrin/4,4'-DDT breakdown check as in Section 15.7.
15.5. Set up the analytical run following this sequential injection pattern: Continuing Calibration Standard, OPR, Solvent Blank, Method Blank, Samples, and
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Solvent Blank.
15.6. Continuing Calibration
15.6.1. Inject a mid-range standard from the initial calibration curve (CS3). The following criteria must be met:
1.) Calculate the concentration of each native compound either by isotope dilution or internal standard technique. Each compound must be within the verification limits established in Table 5.
2.) The ion ratios must be within the limits in Table 3.
3.) The signal to noise ratio (s/n) must exceed 10:1 for all ions monitored.
4.) The absolute retention times of the internal standards shall be within ±15 seconds of the retention times obtained during calibration.
5.) The relative retention times of the peak for a native and labeled pesticide should be within 0.5% of the retention time windows established from the initial calibration curve.
15.6.2. If the above criteria are not met for any compound, correct the problem and repeat the calibration verification, or recalibrate and document return to control.
15.6.3. Perform the Endrin/4,4'-DDT breakdown check as in Section 15.7.
15.7. Endrin/4,4'-DDT breakdown
15.7.1. Measure and sum the peak areas for both exact m/z's separately for 4,4'-DDD, 4,4'-DDE, 4,4'-DDT, endrin, endrin aldehyde, and endrin ketone.
Add the summed peak areas for endrin aldehyde and endrin ketone and separately add the peak areas for 4,4'-DDD and 4,4'-DDE.
Calculate the endrin and 4,4'-DDT breakdown as follows:
Endrin breakdown (%) = (areas for endrin aldehyde + endrin ketone) x 100 areas for endrin
4,4'-DDT breakdown (%) = (areas for 4,4'-DDD + 4,4'-DDE) x 100 areas for 4,4'-DDT
If the breakdown of endrin or 4,4'-DDT exceeds 20%, endrin or 4,4'-DDT is decomposing. If decomposition greater than 20% of either endrin or 4,4'-DDT occurs, clean and recondition the injector, break off a short section of the inlet end of the column, or alter the GC conditions to reduce the decomposition to where the 20% criterion is met.
15.8. Qualitative Determination
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15.8.1. A chromatographic peak is identified as a pesticide or labeled compound when all of the following criteria are met:
1.) The signals for the two exact m/zs being monitored (Table 6 of Method 1699) must be present and must maximize within ±2 seconds of one another.
2.) The signal-to-noise ratio (S/N) of each of the two exact m/zs must be ≥2.5:1 for a sample extract, and ≥10:1 for a calibration standard.
3.) The ratio of the integrated areas of the two exact m/zs must be within the limits established in Table 3.
4.) The relative retention times of the peak for a native and labeled pesticide should be within 0.5% of the retention time windows established from the initial calibration curve.
If the above mentioned criteria are not met, the peak is not identified as a positive.
15.9. Quantitative Determination
15.9.1. Any numerical values that are calculated below the reporting limit are reported as nondetects unless requested otherwise by client.
15.9.2. For peaks which meet the criteria listed above, quantitate the pesticide peaks from the response relative to the appropriate internal standard.
15.9.3. Any peaks representing the other congeners are quantitated using an average of the response factors from all of the labeled pesticides isomers at the same level of chlorination.
15.9.4. Recovery of each internal standard in the samples must be as in Table 5.
15.9.5. If the above-mentioned criteria are not met but the qualitative criteria is met, then the data are qualified appropriately.
16. CALCULATIONS 16.1. The concentrations for pesticide compounds are calculated by using the
formula:
Where:
CX = Concentration of unlabeled pesticide AX = Sum of the integrated ion abundances of the quantitation ions for
unlabeled pesticides AIS = Sum of the integrated ion abundances of the quantitation ion for
the labeled internal standards, QIS = Quantity, in pg, of the internal standard added to the sample
before extraction,
( )( )( )( )( )RRFWA
QACIS
ISXX =
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W = Weight of the sample (solid, dry weight or liquid) DW = Sample wt.× %solids/100 RRF = Calculated relative response factor for the analyte.
16.2. The detection limits can be calculated using the following formula:
Where: DL = Sample specific estimated detection limit, HN = Noise height (peak to peak), HIS = Peak height of the internal standard, Qis = Quantity, in pg, of the internal standard added to the
sample before extraction, W = Weight of the sample (solid or liquid), and RRF = Calculated relative response factor for the analyte.
16.3. The reporting limits can be calculated using the following formula:
( )( )( )
( )Splitsampleof Weight
volume Finalcurveof point Lowof Conc. ExtractRL =
16.4. The Relative Response factor can be calculated using the following formula:
Where: A1N , A2N = Areas of the primary and secondary m/zs for the native
compound A1IS , A2IS = Areas of the primary and secondary m/zs for the labeled
compound. CIS = Concentration of the labeled compound in the calibration
standard. CN = Concentration of the native compound in the calibration
standard
17. POLLUTION PREVENTION 17.1. The solvent evaporation techniques used in this method are amenable to
solvent recovery, and it is recommended that the laboratory recover solvents wherever feasible.
17.2. Standards should be prepared in volumes consistent with laboratory use to minimize disposal of standards.
( )( )( )( )NISIS
ISNN
C2
A1
A
C2
A1
ARRF
+
+=
( )( )( )( )( )( )RRFWH
QH2.5DL
IS
ISN=
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18. WASTE MANAGEMENT 18.1. Waste generated in the procedure must be segregated and disposed
according to the facility hazardous waste procedures. Safety officer should be contacted if additional information is required.
18.2. The laboratory waste management is in compliance with all federal, state, and local regulations to protect the air, water, and land by minimizing and controlling all releases from fume hoods and bench operations.
19. METHOD PERFORMANCE 19.1. This SOP is based on the following method: EPA Method 1699: Pesticides in
Water, Soil, Sediment, Biosolids, and Tissue by HRGC/HRMS, United States Office of Water, EPA No. EPA-821-R-08-001. Environmental Protection Agency (4303T), December 2007
20. REFERENCES 20.1. EPA Method 1699: Pesticides in Water, Soil, Sediment, Biosolids, and Tissue
by HRGC/HRMS, United States Office of Water, EPA No. EPA-821-R-08-001. Environmental Protection Agency (4303T), December 2007
20.2. Vista Analytical Laboratory SOP 9, Manual Integrations.
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Figure 1 Base Silica Gel (BSG)
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Figure 2 250mm Base Silica Gel Column
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Figure 3
CarbonX of Florisil Column (COF)
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Table 1
Method 1699 Target Compounds and Quantitation Limits
Compound Aqueous (pg/L) Solid (pg/g) Hexachlorobutadiene 200 100 Hexachlorobenzene 40 20 alpha-BHC 40 20 Lindane (gamma-BHC) 40 20 beta-BHC 40 20 delta-BHC 40 20 Heptachlor 200 100 DDNU 80 40 Aldrin 40 20 Oxychlordane 40 20 cis-Heptachlor Epoxide 40 20 trans-Heptachlor Epoxide 80 40 trans-Chlordane (gamma) 40 20 trans-Nonachlor 40 20 cis-Chlordane (alpha) 40 20 Endosulfan I (alpha) 400 200 DDMU 400 200 2,4'-DDE 80 40 4,4'-DDE 80 40 Dieldrin 40 20 Endrin 80 40 cis-Nonachlor 40 20 Endosulfan II (beta) 400 200 2,4'-DDD 40 20 2,4'-DDT 80 40 4,4'-DDD 40 20 4,4'-DDT 80 40 Endosulfan Sulfate 400 200 4,4'-Methoxychlor 400 200 Mirex 40 20 Endrin Aldehyde 400 200 Endrin Ketone 400 200
Quantitation limits listed are based upon 1 liter of aqueous sample, 2 gram dry weight solid.
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Table 2
Concentration of Pesticides in Calibration and Calibration Verification Solutions (pg/µL)
Compound CS1 CS2 CS3 CS3.5* CS4 CS5 Hexachlorobutadiene 10 50 125 250 500 1250 Hexachlorobenzene 2 10 25 50 100 250 alpha-BHC 2 10 25 50 100 250 Lindane (gamma-BHC) 2 10 25 50 100 250 beta-BHC 2 10 25 50 100 250 delta-BHC 2 10 25 50 100 250 Heptachlor 10 50 125 250 500 1250 DDNU 4 20 50 100 200 500 Aldrin 2 10 25 50 100 250 Oxychlordane 2 10 25 50 100 250 cis-Heptachlor Epoxide 2 10 25 50 100 250 trans-Heptachlor Epoxide 4 20 50 100 200 500 trans-Chlordane (gamma) 2 10 25 50 100 250 trans-Nonachlor 2 10 25 50 100 250 cis-Chlordane (alpha) 2 10 25 50 100 250 Endosulfan I (alpha) 20 40 50 100 200 500 DDMU 20 40 50 100 200 500 2,4'-DDE 4 20 50 100 200 500 4,4'-DDE 4 20 50 100 200 500 Dieldrin 2 10 25 50 100 250 Endrin 4 20 50 100 200 500 cis-Nonachlor 2 10 25 50 100 250 Endosulfan II (beta) 20 40 50 100 200 500 2,4'-DDD 2 10 25 50 100 250 2,4'-DDT 4 20 50 100 200 500 4,4'-DDD 2 10 25 50 100 250 4,4'-DDT 4 20 50 100 200 500 Endosulfan Sulfate 20 40 50 100 200 500 4,4'-Methoxychlor 20 40 50 100 200 500 Mirex 2 10 25 50 100 250 Endrin Aldehyde 20 40 50 100 200 500 Endrin Ketone 20 40 50 100 200 500 13C4-Hexachlorobutadiene 100 100 100 100 100 100 13C6-Hexachlorobenzene 50 50 50 50 50 50 13C6-alpha-BHC 50 50 50 50 50 50 13C6-Lindane (gamma-BHC) 50 50 50 50 50 50 13C6-beta-BHC 50 50 50 50 50 50 13C6-delta-BHC 50 50 50 50 50 50 13C10-Heptachlor 250 250 250 250 250 250 13C12-Aldrin 50 50 50 50 50 50 13C10-Oxychlordane 50 50 50 50 50 50
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Table 2
Concentration of Pesticides in Calibration and Calibration Verification Solutions (pg/µL)
Compound CS1 CS2 CS3 CS3.5* CS4 CS5 13C10-cis-Heptachlor Epoxide 50 50 50 50 50 50 13C10-trans-Chlordane (gamma) 50 50 50 50 50 50 13C10-trans-Nonachlor 50 50 50 50 50 50 13C9-Endosulfan I (alpha) 100 100 100 100 100 100 13C12-2,4'-DDE 50 50 50 50 50 50 13C12-4,4'-DDE 50 50 50 50 50 50 13C12-Dieldrin 50 50 50 50 50 50 13C12-Endrin 100 100 100 100 100 100 13C10-cis-Nonachlor 50 50 50 50 50 50 13C9-Endosulfan II (beta) 100 100 100 100 100 100 13C12-2,4'-DDD 50 50 50 50 50 50 13C12-2,4'-DDT 100 100 100 100 100 100 13C12-4,4'-DDD 50 50 50 50 50 50 13C12-4,4'-DDT 100 100 100 100 100 100 13C9-Endosulfan sulfate 500 500 500 500 500 500 13C12-Methoxychlor 500 500 500 500 500 500 13C10-Mirex 50 50 50 50 50 50 13C12-Endrin aldehyde 500 500 500 500 500 500 13C12-Endrin ketone 500 500 500 500 500 500 13C-PCB-15 50 50 50 50 50 50 13C-PCB-52 50 50 50 50 50 50 13C-PCB-60 50 50 50 50 50 50 13C-PCB-123 50 50 50 50 50 50 13C-PCB-138 50 50 50 50 50 50 d8-4,4’-DDD 100 100 100 100 100 100
* Calibration Verification Solution
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Table 3
Theoretical Ion Abundance Ratios and QC Limits
Compound Ion Abundance Ratio
QC Limits m1/m2
Tol (+/-)
Hexachlorobutadiene 0.94 – 1.56 1.25 0.25 Hexachlorobenzene 0.94 – 1.56 1.25 0.25 alpha-BHC 1.56 – 2.60 2.08 0.25 Lindane (gamma-BHC) 1.56 – 2.60 2.08 0.25 beta-BHC 1.56 – 2.60 2.08 0.25 delta-BHC 1.56 – 2.60 2.08 0.25 Heptachlor 0.94 – 1.56 1.25 0.25 DDNU 2.35 – 3.91 3.13 0.25 Aldrin 1.17 – 1.95 1.56 0.25 Oxychlordane 1.17 – 1.95 1.56 0.25 cis-Heptachlor Epoxide 1.17 – 1.95 1.56 0.25 trans-Heptachlor Epoxide 1.17 – 1.95 1.56 0.25 trans-Chlordane (gamma) 1.17 – 1.95 1.56 0.25 trans-Nonachlor 1.17 – 1.95 1.56 0.25 cis-Chlordane (alpha) 1.17 – 1.95 1.56 0.25 Endosulfan I (alpha) 1.17 – 1.95 1.56 0.25 DDMU 1.17 – 1.95 1.56 0.25 2,4'-DDE 1.17 – 1.95 1.56 0.25 4,4'-DDE 1.17 – 1.95 1.56 0.25 Dieldrin 1.17 – 1.95 1.56 0.25 Endrin 1.17 – 1.95 1.56 0.25 cis-Nonachlor 1.17 – 1.95 1.56 0.25 Endosulfan II (beta) 1.17 – 1.95 1.56 0.25 2,4'-DDD 1.17 – 1.95 1.56 0.25 2,4'-DDT 1.17 – 1.95 1.56 0.25 4,4'-DDD 1.17 – 1.95 1.56 0.25 4,4'-DDT 1.17 – 1.95 1.56 0.25 Endosulfan Sulfate 1.17 – 1.95 1.56 0.25 4,4'-Methoxychlor * * 0.35 Mirex 1.17 – 1.95 1.56 0.25 Endrin Aldehyde 0.47 – 0.79 0.63 0.25 Endrin Ketone 0.47 – 0.79 0.63 0.25 13C4-Hexachlorobutadiene 0.94 – 1.56 1.25 0.25 13C6-Hexachlorobenzene 0.94 – 1.56 1.25 0.25 13C6-alpha-BHC 0.58 – 0.96 0.77 0.25 13C6-Lindane (gamma-BHC) 0.58 – 0.96 0.77 0.25
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Vista Analytical Laboratory El Dorado Hills, CA 95762
Table 3
Theoretical Ion Abundance Ratios and QC Limits
Compound Ion Abundance Ratio
QC Limits m1/m2
Tol (+/-)
13C6-beta-BHC 0.58 – 0.96 0.77 0.25 13C6-delta-BHC 0.58 – 0.96 0.77 0.25 13C10-Heptachlor 0.93 – 1.55 1.24 0.25 13C12-Aldrin 1.17 – 1.95 1.56 0.25 13C10-Oxychlordane 1.17 – 1.95 1.56 0.25 13C10-cis-Heptachlor Epoxide 1.17 – 1.95 1.56 0.25 13C10-trans-Chlordane (gamma) 1.17 – 1.95 1.56 0.25 13C10-trans-Nonachlor 1.17 – 1.95 1.56 0.25 13C9-Endosulfan I (alpha) 1.17 – 1.95 1.56 0.25 13C12-2,4'-DDE 1.17 – 1.95 1.56 0.25 13C12-4,4'-DDE 1.17 – 1.95 1.56 0.25 13C12-Dieldrin 1.17 – 1.95 1.56 0.25 13C12-Endrin 1.17 – 1.95 1.56 0.25 13C10-cis-Nonachlor 1.17 – 1.95 1.56 0.25 13C9-Endosulfan II (beta) 1.17 – 1.95 1.56 0.25 13C12-2,4'-DDD 1.17 – 1.95 1.56 0.25 13C12-2,4'-DDT 1.17 – 1.95 1.56 0.25 13C12-4,4'-DDD 4.73 – 7.88 6.30 0.25 13C12-4,4'-DDT 1.17 – 1.95 1.56 0.25 13C9-Endosulfan sulfate 1.17 – 1.95 1.56 0.25 13C12-Methoxychlor * * 0.35 13C10-Mirex 1.17 – 1.95 1.56 0.25 13C12-Endrin aldehyde * * 0.25 13C12-Endrin ketone * * 0.25
* Indicates abundance ratio calculated off the average ICAL value or CCAL value
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Vista Analytical Laboratory El Dorado Hills, CA 95762
Table 4
Exact Masses Monitored
Compound M1 M2 Hexachlorobutadiene 259.8102 261.8072 Hexachlorobenzene 283.8102 285.8072 alpha-BHC 218.9116 220.9086 Lindane (gamma-BHC) 218.9116 220.9086 beta-BHC 218.9116 220.9086 delta-BHC 218.9116 220.9086 Heptachlor 271.8102 273.8072 DDNU 213.0471 215.0442 Aldrin 262.8569 264.8550 Oxychlordane 262.8569 264.8550 cis-Heptachlor Epoxide 262.8569 264.8550 trans-Heptachlor Epoxide 262.8569 264.8550 trans-Chlordane (gamma) 262.8569 264.8550 trans-Nonachlor 262.8569 264.8550 cis-Chlordane (alpha) 262.8569 264.8550 Endosulfan I (alpha) 262.8569 264.8550 DDMU 246.0003 247.9974 2,4'-DDE 246.0003 247.9974 4,4'-DDE 246.0003 247.9974 Dieldrin 262.8569 264.8550 Endrin 262.8569 264.8550 cis-Nonachlor 262.8569 264.8550 Endosulfan II (beta) 262.8569 264.8550 2,4'-DDD 235.0081 237.0052 2,4'-DDT 235.0081 237.0052 4,4'-DDD 235.0081 237.0052 4,4'-DDT 235.0081 237.0052 Endosulfan Sulfate 262.8569 264.8540 4,4'-Methoxychlor 227.1072 228.1106 Mirex 236.8413 238.8384 Endrin Aldehyde 247.8521 249.8491 Endrin Ketone 247.8521 249.8491 13C4-Hexachlorobutadiene 263.8236 265.8206 13C6-Hexachlorobenzene 289.8303 291.8273 13C6-alpha-BHC 222.9346 224.9317 13C6-Lindane (gamma-BHC) 222.9346 224.9317 13C6-beta-BHC 222.9346 224.9317 13C6-delta-BHC 222.9346 224.9317 13C10-Heptachlor 276.8269 278.8240 13C12-Aldrin 269.8804 271.8775
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Table 4
Exact Masses Monitored
Compound M1 M2 13C10-Oxychlordane 269.8804 271.8775 13C10-cis-Heptachlor Epoxide 269.8804 271.8775 13C10-trans-Chlordane (gamma) 269.8804 271.8775 13C10-trans-Nonachlor 269.8804 271.8775 13C9-Endosulfan I (alpha) 269.8804 271.8775 13C12-2,4'-DDE 258.0406 260.0376 13C12-4,4'-DDE 258.0406 260.0376 13C12-Dieldrin 269.8804 271.8775 13C12-Endrin 269.8804 271.8775 13C10-cis-Nonachlor 269.8804 271.8775 13C9-Endosulfan II (beta) 269.8804 271.8775 13C12-2,4'-DDD 247.0484 249.0454 13C12-2,4'-DDT 247.0484 249.0454 13C12-4,4'-DDD 249.0454 251.0425 13C12-4,4'-DDT 247.0484 249.0454 13C9-Endosulfan sulfate 269.8804 271.8775 13C12-Methoxychlor 239.1475 240.1508 13C10-Mirex 241.8581 243.8551 13C12-Endrin aldehyde 253.8722 255.8693 13C12-Endrin ketone 253.8722 255.8693 13C-PCB-15 234.0406 236.0376 13C-PCB-52 301.9626 303.9597 13C-PCB-60 301.9626 303.9597 13C-PCB-123 337.8820 339.9180 13C-PCB-138 371.8820 373.8790 d8-4,4’-DDD 243.0575 245.0546
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Table 5
Acceptance Criteria for Pesticides in QC
Compound VER (%) OPR (%) Recovery in Samples (%)
Hexachlorobutadiene 75 – 125 50 – 120 NA Hexachlorobenzene 75 – 125 50 – 120 NA alpha-BHC 75 – 125 50 – 120 NA Lindane (gamma-BHC) 75 – 125 50 – 120 NA beta-BHC 75 – 125 50 – 120 NA delta-BHC 75 – 125 50 – 120 NA Heptachlor 75 – 125 50 – 120 NA DDNU 75 – 125 50 – 120 NA Aldrin 75 – 125 50 – 120 NA Oxychlordane 75 – 125 50 – 120 NA cis-Heptachlor Epoxide 75 – 125 50 – 120 NA trans-Heptachlor Epoxide 75 – 125 50 – 120 NA trans-Chlordane (gamma) 75 – 125 50 – 120 NA trans-Nonachlor 75 – 125 50 – 120 NA cis-Chlordane (alpha) 75 – 125 50 – 120 NA Endosulfan I (alpha) 75 – 125 50 – 120 NA DDMU 75 – 125 50 – 120 NA 2,4'-DDE 75 – 125 24 – 123 NA 4,4'-DDE 75 – 125 50 – 120 NA Dieldrin 75 – 125 50 – 120 NA Endrin 75 – 125 50 – 120 NA cis-Nonachlor 75 – 125 50 – 120 NA Endosulfan II (beta) 75 – 125 5 – 200 NA 2,4'-DDD 75 – 125 50 – 120 NA 2,4'-DDT 75 – 125 50 – 120 NA 4,4'-DDD 75 – 125 42 – 120 NA 4,4'-DDT 75 – 125 50 – 120 NA Endosulfan Sulfate 75 – 125 50 – 200 NA 4,4'-Methoxychlor 75 – 125 50 – 120 NA Mirex 75 – 125 50 – 120 NA Endrin Aldehyde 75 – 125 50 – 134 NA Endrin Ketone 75 – 125 50 – 134 NA 13C4-Hexachlorobutadiene 70 – 130 25 – 150 25 – 150 13C6-Hexachlorobenzene 70 – 130 5 – 120 5 – 120 13C6-alpha-BHC 70 – 130 17 – 141 32 – 130 13C6-Lindane (gamma-BHC) 70 – 130 5 – 124 11 – 120 13C6-beta-BHC 70 – 130 17 – 141 32 – 130 13C6-delta-BHC 70 – 130 16 – 150 36 – 137 13C10-Heptachlor 70 – 130 5 – 128 5 – 120
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Table 5
Acceptance Criteria for Pesticides in QC
Compound VER (%) OPR (%) Recovery in Samples (%)
13C12-Aldrin 70 – 130 5 – 126 5 – 120 13C10-Oxychlordane 70 – 130 5 – 144 23 – 135 13C10-cis-Heptachlor Epoxide 70 – 130 8 – 146 27 – 137 13C10-trans-Chlordane (gamma) 70 – 130 15 – 144 21 – 132 13C10-trans-Nonachlor 70 – 130 13 – 149 14 – 136 13C9-Endosulfan I (alpha) 70 – 130 5 – 144 15 – 148 13C12-2,4'-DDE 70 – 130 26 – 169 47 – 160 13C12-4,4'-DDE 70 – 130 26 – 169 47 – 160 13C12-Dieldrin 70 – 130 19 – 161 40 – 151 13C12-Endrin 70 – 130 20 – 157 35 – 155 13C10-cis-Nonachlor 70 – 130 17 – 154 36 – 139 13C9-Endosulfan II (beta) 70 – 130 5 – 120 5 – 122 13C12-2,4'-DDD 70 – 130 14 – 200 5 – 199 13C12-2,4'-DDT 70 – 130 14 – 200 5 – 199 13C12-4,4'-DDD 70 – 130 14 – 200 5 – 120 13C12-4,4'-DDT 70 – 130 13 – 200 5 – 120 13C9-Endosulfan sulfate 70 – 130 5 – 144 15 – 148 13C12-Methoxychlor 70 – 130 14 – 200 5 – 199 13C10-Mirex 70 – 130 5 – 138 5 – 120 13C12-Endrin aldehyde 70 – 130 5 – 144 15 – 148 13C12-Endrin ketone 70 – 130 5 – 144 15 – 148
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GLOSSARY Symbols °C Celsius µL microliter µm micrometer < less than > greater than % percent
Alphabetical Abbreviations cm centimeter g gram L liter M molecular ion m meter mg milligram ml milliliter mm millimeter m/z mass-to-charge ration N normal pg picogram ppb part-per-billion ppm part-per-million ppq part-per-quadrillion ppt part-per-trillion v/v volume per unit volume w/v weight per unit volume
Definitions and Acronyms Calibration Standard – a solution prepared from a secondary standard and/or stock solutions and used to calibrate the response of the instrument.
Calibration Verification Standard – the mid-point calibration standard (CS-3) that is used to verify calibration.
CB – chlorinated biphenyl congener.
CS-0, CS-1, CS-2, CS-3, CS-4, CS-5 – See calibration standards and Table 2.
HRMS – High resolution mass spectrometry.
Internal Standard – an internal standard is a labeled analyte which is added to all field samples, blanks and other quality control samples before extraction. It is also included in the calibration solutions. Internal standards are used to measure the concentration of the analyte and surrogate compounds.
IPR – initial precision and recovery, four aliquots of a reference matrix spiked with the analytes of interest and labeled compounds and analyzed to establish the ability of the laboratory to generated acceptable precision and recovery.
Isotope Dilution – a means of determining a naturally occurring (native) compound by reference to the same compound in which one or more atoms has been isotopically enriched.
Matrix Spike (MS) – a sample prepared by adding a known mass of target analyte to a specified amount of matrix sample for which an independent estimate of target analyte is concentration is available. Matrix spikes are used, for example, to determine the effect of the matrix on the methods recovery efficiency.
Method Blank (MB) – an aliquot of reagent water that is treated exactly as a sample including exposure to all glassware, equipment, solvents, regents, internal standards, and surrogates that are used with samples. The method blank is used to determine if analytes or interferences are
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present in the laboratory environment, the reagents, or the apparatus.
Minimum Level – The level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that all Method-specified sample weights, volumes, and cleanup procedures have been employed.
OPR – ongoing precision and recovery standard, a method blank spiked with known quantities of analytes. The OPR is analyzed exactly like a sample. Its purpose is to assure that the results produced by the laboratory remain within the limits specified in this method for precision and recovery.
PFK – perfluorokerosene, a mixture of compounds used to calibrate the exact m/z scale in the HRMS.
Practical Quantitation Limit (PQL) – The PQL is a limit for each compound at or below which data must not be reported.
Reagent Water – water demonstrated to be free from the analytes of interest and potentially interfering substances at the method detection limit for the analyte.
Recovery Standard – A recovery standard is a labeled compound, which is added to the extracts of all samples, blanks, and QC samples before analysis. It is also included in the calibration solutions. The response of the internal standards relative to the recovery standard is used to estimate the recovery of the internal standards. The internal standard recovery is an indicator of the overall performance of the analysis.
Relative Response Factor – The relative response factor is the response of the mass spectrometer to a known amount of an analyte or labeled compound relative to a known amount of an internal standard or another labeled compound.
Signal-to-Noise Ratio (S/N) – the height of the signal as measured from the mean (average) of the noise to the peak maximum divided by the width of the noise.
Stock Solution – a solution containing an analyte that is prepared using a reference material traceable to a source that will attest to the purity and authenticity of the reference material.
