EPA Method 8070A Nitrosamines by Gas Chromatography - Revision 1
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F1CE1557BF3D4345981E799B620DF2CD |
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文件大小(MB)： |
0.08 |
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页数： |
14 |
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日期： |
2003-1-16 |
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CD-ROM 8070A - 1 Revision 1,December 1996,METHOD 8070A,NITROSAMINES BY GAS CHROMATOGRAPHY,1.0 SCOPE AND APPLICATION,1.1 Method 8070 is a gas chromatographic (GC) method applicable to the determination of,nitrosamine in aqueous matrices such as groundwater and municipal and industrial discharges. It,is also applicable to solid matrices such as soils, sediments, and sludges. Specifically, this method,covers the determination of the following compounds:,Appropriate Technique,Compound CAS No.a 3510 3520 3540/1 3550 3580,N-Nitrosodimethylamine 62-75-9 X X X X X,N-Nitrosodiphenylamine 86-30-6 X X X X X,N-Nitrosodi-n-propylamine 621-64-7 X X X X X,a Chemical Abstract Service Registry Number.,X Greater than 70 percent recovery by this preparation technique.,1.2 The method detection limit (MDL) for each analyte of interest 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. This method has been tested for linearity of recovery from spiked,organic-free reagent water and has been demonstrated to be applicable for the concentration range,from 4 x MDL to 1000 x MDL.,1.3 When this method is used to analyze samples from matrices that are not well,characterized, compound identifications should be confirmed by at least one additional qualitative,technique. Secondary confirmation can be performed using a dissimilar GC column, specific,element detector, or mass spectrometer (MS).,1.4 The toxicity or carcinogenicity of each reagent used in this method has not been precisely,defined. However, each chemical compound should be treated as a potential health hazard. From,this viewpoint, exposure to these chemicals must be reduced to the lowest possible concentration,by whatever means available. The laboratory is responsible for maintaining a current awareness file,of OSHA regulations regarding the safe handling of the chemicals specified in this method. A,reference file of material safety data sheets should also be made available to all personnel involved,in the chemical analysis.,1.5 These nitrosamines are known carcinogens. Therefore, utmost care must be exercised,in the handling of these materials. Nitrosamine reference standards and standard solutions should,be handled and prepared in a ventilated glove box within a properly ventilated room.,1.6 N-Nitrosodiphenylamine is reported to undergo transnitrosation reactions. Care must be,exercised in the heating or concentrating of solutions containing this compound in the presence of,reactive amines.,CD-ROM 8070A - 2 Revision 1,December 1996,1.7 This method is restricted to use by, or under the supervision of, analysts experienced in,the use of gas chromatographs and skilled in the interpretation of gas chromatograms. Each analyst,must demonstrate the ability to generate acceptable results with this method.,2.0 SUMMARY OF METHOD,2.1 A measured volume of sample is solvent extracted with methylene chloride using an,appropriate sample preparation technique. The methylene chloride extract is washed with dilute HCl,to remove free amines, dried, and concentrated to a volume of 10 mL or less. Gas chromatographic,conditions are described which permit the separation and measurement of the compounds in the,extract after it has been exchanged to methanol.,2.2 Method 8070 provides gas chromatographic conditions for the detection of ppb,concentrations of nitrosamines. Prior to use of this method, appropriate sample extraction,techniques must be used. Both neat and diluted organic liquids (Method 3580, Waste Dilution) may,be analyzed by direct injection. A 2- to 5-μL aliquot of the extract is injected into a GC using the,solvent flush technique, and compounds in the GC effluent are detected by a nitrogen-phosphorus,detector (NPD), or a Thermal Energy Analyzer and the reductive Hall detector.,3.0 INTERFERENCES,3.1 Refer to Methods 3500, 3600, and 8000.,3.2 Matrix interferences may be caused by contaminants that are co-extracted from the,sample. The extent of matrix interferences will vary considerably from source to source, depending,upon the nature and diversity of the industrial complex or municipality being sampled. The cleanup,procedures (Methods 3610 or 3620) can be used to overcome many of these interferences, but,unique samples may require additional cleanup approaches to achieve the MDL listed in Table 1.,3.3 Nitrosamines contaminate many types of products commonly found in the laboratory. The,analyst must demonstrate that no nitrosamine residues contaminate the sample or solvent extract,under the conditions of analysis. Plastics, in particular, must be avoide……
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