EPA Method 615 Chlorinated Herbicides
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ID： |
ED22EB30643D49A1B3775670014C0F07 |
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文件大小(MB)： |
0.08 |
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页数： |
21 |
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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 615,The Determination of,Chlorinated Herbicides in,Municipal and Industrial,Wastewater,Method 615,The Determination of Chlorinated Herbicides in Municipal and,Industrial Wastewater,1. SCOPE AND APPLICATION,1.1 This method covers the determination of certain chlorinated herbicides. The following,parent acids can be determined by this method:,Parameter STORET No. CAS No.,2,4-D 39736 94-75-7,Dalapon - 75-99-0,2,4-DB - 94-82-6,Dicamba - 1918-00-9,Dichlorprop - 120-36-5,Dinoseb - 88-85-7,MCPA - 94-74-6,MCPP - 7085-19-0,2,4,5-T 39740 93-76-5,2,4,5-TP 39760 93-72-1,1.2 This method is also applicable to the determination of salts and esters of these,compounds. These include, but are not limited to: the isobutyl and isooctyl esters of,2,4-D; the isobutyl and isooctyl esters of 2,4-DB; the isooctyl ester of MCPA; and the,isooctyl ester of 2,4,5-TP. The actual form of each acid is not distinguished by this,method. Results are calculated and reported for each listed parameter as total free acid.,1.3 This is a gas chromatographic (GC) method applicable to the determination 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 alternative test,procedures under 40 CFR 136.4 and 136.5.,1.4 The method detection limit (MDL, defined in Section 15) for each parameter is listed in,Table 1. The MDL for a specific wastewater may differ from those listed, depending,upon the nature of interferences in the sample matrix.,1.5 This method is restricted to use by or under the supervision of analysts experienced in,the use of gas chromatography and in the interpretation of gas chromatograms. Each,analyst must demonstrate the ability to generate acceptable results with this method,using the procedure described in Section 8.2.,1.6 When this method is used to analyze unfamiliar samples for any or all of the compounds,above, compound identifications should be supported by at least one additional,qualitative technique. This method describes analytical conditions for alternative gas,chromatographic columns that can be used to confirm measurements made with the,Method 615,primary column. Section 15 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 L, is acidified. The acid herbicides and,their esters and salts are extracted with ethyl ether using a separatory funnel. The,derivatives are hydrolyzed with potassium hydroxide and extraneous organic material,is removed by a solvent wash. After acidification, the acids are extracted and converted,to their methyl esters using diazomethane as the derivatizing agent. Excess reagent is,removed, and the esters are determined by electron capture (EC) gas chromatography.1,3. 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 chromatograms. 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 dilute acid, tap,and reagent water. Drain dry, and heat in an oven or muffle furnace at 400°C for,15 to 30 minutes. Do not heat volumetric ware. Thermally stable materials, such,as PCBs, may 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 minimize interference,problems. Purification of solvents by distillation in all-glass systems may be,required.,3.2 The acid forms of the herbicides are strong organic acids, which react readily with,alkaline substances and can be lost during analysis. Glassware and glass wool must be,acid-rinsed with (1+9) hydrochloric acid and the sodium sulfate must be acidified with,sulfuric acid prior to use to avoid this possibility.,3.3 Organic acids and phenols, especially chlorinated compoun……
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