EPA Method 1657 Organo-Phosphorus Pesticides
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ID： |
6D1C43E9E3C44C77B22556945B40AC37 |
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文件大小(MB)： |
0.16 |
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页数： |
39 |
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文件格式： |
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日期： |
2008-2-26 |
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购买： |
文本摘录（文本识别可能有误，但文件阅览显示及打印正常，pdf文件可进行文字搜索定位）：
Method 1657,The Determination of,Organo-Phosphorus Pesticides,in Municipal and Industrial,Wastewater,Method 1657,The Determination of Organo-Phosphorus Pesticides in Municipal and,Industrial Wastewater,1. SCOPE AND APPLICATION,1.1 This method is designed to meet the survey requirements of the Environmental,Protection Agency (EPA). It is used to determine the (1) organo-phosphorus pesticides,associated with the Clean Water Act, the Resource Conservation and Recovery Act, and,the Comprehensive Environmental Response, Compensation and Liability Act; and (2),other compounds amenable to extraction and analysis by automated, wide-bore capillary,column gas chromatography (GC) with a flame photometric detector.,1.2 The compounds listed in Table 1 may be determined in waters, soils, sediments, and,sludges by this method. The method is a consolidation of several EPA methods. For,waters, the sample extraction and concentration steps are essentially the same as in these,methods. However, the extraction and concentration steps have been extended to other,sample matrices. The method may be applicable to other phosphorus containing,pesticides. The quality assurance/quality control requirements in this method give the,steps necessary to determine this applicability. Not all compounds listed in Table 1 have,corresponding calibration data in Table 3 and acceptance criteria in Table 4. Calibration,data for such analytes may be found in other EPA methods (References 1 and 2).,1.3 This method is applicable to a large number of compounds. Calibrating the GC systems,for all compounds is time-consuming. If only a single compound or small number of,compounds is to be tested for, it is necessary to calibrate the GC systems and meet the,performance specifications in this method for these compounds only. In addition, the GC,conditions can be optimized for these compounds provided that all performance,specifications in this method are met.,1.4 When this method is applied to analysis of unfamiliar samples, compound identity must,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. Gas chromatography/mass,spectrometry (GC/MS) can be used to confirm compounds in extracts produced by this,method when analyte levels are sufficient.,1.5 The detection limits of this method are usually dependent on the level of interferences,rather than instrumental limitations. The limits in Table 2 typify the minimum quantities,that can be detected with no interferences present.,1.6 This method is for use by or under the supervision of analysts experienced in the use of,a gas chromatograph and in the interpretation of gas chromatographic data. Each,laboratory that uses this method must demonstrate the ability to generate acceptable,results using the procedure in Section 8.2.,2. SUMMARY OF METHOD,Method 1657,2.1 Extraction.,2.1.1 The percent solids content of a sample is determined.,2.1.2 Aqueous samples containing less than or equal to 1% solids.,2.1.2.1 Samples containing water-insoluble compounds: A 1-L sample is,extracted with methylene chloride using continuous extraction techniques.,2.1.2.2 Samples containing highly water-soluble compounds such as,methamidophos: Salt is added to a 1-L sample and the sample is,extracted with an azeotropic mixture of chloroform:acetone using,continuous extraction techniques.,2.1.3 Samples containing greater than 1% solids.,2.1.3.1 Non-sludge samples: If the solids content is 1 to 30%, the sample is,diluted to 1% solids with reagent water, homogenized ultrasonically, and,extracted as an aqueous sample. If the solids content is greater than 30%,the sample is extracted with methylene chloride:acetone using ultrasonic,techniques.,2.1.3.2 Municipal sludge samples and other intractable sample types: If the solids,content is less than 30%, the sample is diluted to 1% solids and extracted,as an aqueous sample. If the solids content is greater than 30%, the,sample is extracted with acetonitrile and then methylene chloride using,ultrasonic techniques. The extract is back-extracted with 2% (w/v),sodium sulfate in reagent water to remove water-soluble interferences and,residual acetonitrile.,2.2 Concentration and cleanup: Each extract is dried over sodium sulfate, concentrated using,a Kuderna-Danish evaporator, cleaned up (if necessary) using gel permeation,chromatography (GPC) and/or solid-phase extraction, and concentrated to 1 mL.,2.3 Gas chromatography: A fixed volume of the extract is injected into the gas,chromatograph (GC). The com……
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