【国外标准】 Standard Test Method for Determination of Pesticides and Polychlorinated Biphenyls (PCBs) in Aqueous Solution by a Tandem Gas Chromatography/Mass Spectrometry/Mass Spectrometry (GC/MS/MS)

5.1 Pesticides and PCBs are Environmental Protection Agency (EPA)-regulated contaminants in treated drinking water, wastewater, and ground water. Liquid-liquid and solid-phase extraction (SPE) are generally applicable procedures for extracting these target analytes before GC/MS/MS analysis.5.2 This test method is applicable to pesticides that are extracted from aqueous solution using methylene chloride and can be chromatographed and detected using tandem mass spectrometry procedures. Table 1 lists pesticides and Table 2 lists PCBs validated by this test method. This test method is not limited to the compounds listed in Table 1 or Table 2; however, the applicability of the test method to other compounds shall be demonstrated. Refer to Guide E2857 for guidance in validating the method for additional parameters.5.3 Analyte concentrations up to approximately 250 ng/L may be determined. Analytes that are inefficiently extracted from water will not be detected when present at low concentrations, but they can be measured with acceptable accuracy and precision when present in sufficient amounts.5.4 Analytes that are not separated chromatographically but that have different transitions can be identified and quantitatively measured.5.5 This test method may be used to determine the concentrations of Aroclor6 mixtures or PCB congeners, or both, present in the sample. See Appendix X1 and Appendix X2 for suggested transitions and collisional energies for all 209 congeners. Separation of all 209 congeners may not be possible and may require additional GC columns and operating conditions. Analysis of all congeners is not expected to be achieved by this test method.5.6 Method detection limits (MDL) and minimum reporting level (MRL) for analytes in Tables 1 and 2 are given in Table 3. These limits must be met if the method is used for National Pollutant Discharge Elimination System (NPDES) reporting.(A) Priority Pollutant listed in Table 1 of EPA Method 608.3.(B) Priority Pollutant listed in Table 2 of EPA Method 608.3.1.1 This test method covers the identification and simultaneous measurement of extractable chlorinated pesticides and polychlorinated biphenyls (PCBs) by gas chromatography/mass spectrometry/mass spectrometry (GC/MS/MS).1.2 This test method has been validated for wastewater influents, effluents, industrial discharges, surface water, and ground water.1.3 This test method is not limited to these particular aqueous matrices; however, the applicability of this test method to other aqueous matrices shall be demonstrated.1.4 This test method is restricted to use by or under the supervision of analysts experienced in the use of a gas chromatograph with tandem mass spectrometry. Each laboratory that uses this test method shall demonstrate the ability to generate results that meet or exceed the performance criteria of this test method.1.5 If sensitivity permits, compound tentative identification of unknowns may be made by analyzing the extract in full-scan mode or, if the system allows simultaneous timed single-reaction monitoring (SRM)/full-scan acquisition. Identify unknown peaks according to Guide D4128.1.6 This test method is performance-based. Minor modifications, as allowed by CFR 40 Part 136.6, may be made to improve the method performance, but changes may not be made to the extraction, the extraction solvent, sample-to-solvent ratio, or the MS/MS detection technique.1.7 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.