EPA Method 602 Purgeable Aromatics
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ID： |
1415ABD5CE004598000062832C00EDEC |
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文件大小(MB)： |
0.23 |
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页数： |
22 |
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文件格式： |
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日期： |
2003-1-16 |
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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）：
APPENDIX A TO PART 136,METHODS FOR ORGANIC CHEMICAL ANALYSIS OF MUNICIPAL AND,INDUSTRIAL WASTEWATER,METHOD 602—PURGEABLE AROMATICS,1. Scope and Application,1.1 This method covers the determination of various purgeable aromatics. The following,parameters may be determined by this method:,Parameter STORET CAS No.,No.,Benzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34030 71-43-2,Chlorobenzene . . . . . . . . . . . . . . . . . . . . . . 34301 108-90-7,1,2-Dichlorobenzene . . . . . . . . . . . . . . . . . . 34536 95-50-1,1,3-Dichlorobenzene . . . . . . . . . . . . . . . . . . 34566 541-73-1,1,4-Dichlorobenzene . . . . . . . . . . . . . . . . . . 34571 106-46-7,Ethylbenzene . . . . . . . . . . . . . . . . . . . . . . . . 34371 100-41-4,Toluene . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34010 108-88-3,1.2 This is a purge and trap gas chromatographic (GC) method applicable to the,determination of the compounds listed above in municipal and industrial discharges as,provided under 40 CFR Part 136.1. 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 a second gas chromatographic column that can be used to,confirm measurements made with the primary column. Method 624 provides gas,chromatograph/mass spectrometer (GC/MS) conditions appropriate for the qualitative,and quantitative confirmation of results for all of the parameters listed above.,1.3 The method detection limit (MDL, defined in Section 12.1)1 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.,1.4 Any modification of this method, beyond those expressly permitted, shall be considered,as a major modification subject to application and approval of alternate test procedures,under 40 CFR Parts 136.4 and 136.5.,1.5 This method is restricted to use by or under the supervision of analysts experienced in,the operation of a purge and trap system and a gas chromatograph 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.,2. Summary of Method,2.1 An inert gas is bubbled through a 5 mL water sample contained in a specially-designed,purging chamber at ambient temperature. The aromatics are efficiently transferred from,the aqueous phase to the vapor phase. The vapor is swept through a sorbent trap where,the aromatics are trapped. After purging is completed, the trap is heated and,backflushed with the inert gas to desorb the aromatics onto a gas chromatographic,column. The gas chromatograph is temperature programmed to separate the aromatics,which are then detected with a photoionization detector.2,3,2.2 The method provides an optional gas chromatographic column that may be helpful in,resolving the compounds of interest from interferences that may occur.,3. Interferences,3.1 Impurities in the purge gas and organic compounds outgassing from the plumbing ahead,of the trap account for the majority of contamination problems. The analytical system,must be demonstrated to be free from contamination under the conditions of the analysis,by running laboratory reagent blanks as described in Section 8.1.3. The use of non-Teflon,plastic tubing, non-Teflon thread sealants, or flow controllers with rubber components,in the purge and trap system should be avoided.,3.2 Samples can be contaminated by diffusion of volatile organics through the septum seal,into the sample during shipment and storage. A field reagent blank prepared from,reagent water and carried through the sampling and handling protocol can serve as a,check on such contamination.,3.3 Contamination by carry-over can occur whenever high level and low level samples are,sequentially analyzed. To reduce carry-over, the purging device and sample syringe,must be rinsed with reagent water between sample analyses. Whenever an unusually,concentrated sample is encountered, it should be followed by an analysis of reagent,water to check for cross contamination. For samples containing large amounts of,water-soluble materials, suspended solids, high boiling compounds or high aromatic,levels, it may be necessary to wash the purging device with a detergent solution, rinse,it with distilled water, and then dry it in an oven at 105°C between analyses. The trap,and other parts of the system are also subject to contamination; therefore, frequent,bakeout and ……
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