ISBN: 9781234881481

Rarebooksclub.com. Paperback. New. This item is printed on demand. Paperback. 100 pages. OCLC Number: 56082718 Excerpt: . . . Method 1666, Revision A 2. 2. 1 The percent solids content … More...

Rarebooksclub.com. Paperback. New. This item is printed on demand. Paperback. 100 pages. OCLC Number: 56082718 Excerpt: . . . Method 1666, Revision A 2. 2. 1 The percent solids content of the sample is determined. If the solids content is known or determined to be less than 1 , stable, isotopically labeled analogs of the compounds of interest are added to a 5-mL sample. If the solids content of the sample is greater than 1 , 5 mL of reagent water and the labeled compounds are added to a 5-g aliquot of sample. The mixture is sonicated in a centrifuge vial with little or no headspace for 5 minutes. During this period the native analytes and labeled analogs will equilibrate between the solid and aqueous phases. In some cases, additional sonication will be necessary to establish equilibrium. The resulting suspension is centrifuged and the supernatant liquid analyzed. 2. 2. 2 One L or more of the aqueous solution ( or supernate ) is injected into the GC MS. The compounds are separated by the GC and detected by the MS ( References 2 and 3 ). The labeled compounds serve to correct the variability of the analytical technique. 2. 3 Identification of a pollutant ( qualitative analysis ) is performed by calibrating the GC MS with authentic standards and storing a mass spectrum and retention time for each compound in a user-created library. A compound is identified when its retention time and mass spectrum agree with the library retention time and spectrum. 2. 4 Quantitative analysis is performed in one of two ways by using extracted-ion current profile ( EICP ) areas. ( 1 ) For those compounds listed in Table 1 and Table 2, and for other compounds for which labeled analogs are available, the GC MS system is calibrated and the compound concentration is determined using an isotope dilution technique. ( 2 ) For those compounds listed in Table 1 and Table 2, and for other compounds for which authentic standards but no labeled compounds are available, the GC MS system is calibrated and the compound concentration is determined using an internal standard techni. . . This item ships from La Vergne,TN., Rarebooksclub.com<

ISBN: 9781234881481

RareBooksClub. Paperback. New. This item is printed on demand. Paperback. 100 pages. OCLC Number: 56082718 Excerpt: . . . Method 1666, Revision A 2. 2. 1 The percent solids content of t… More...

RareBooksClub. Paperback. New. This item is printed on demand. Paperback. 100 pages. OCLC Number: 56082718 Excerpt: . . . Method 1666, Revision A 2. 2. 1 The percent solids content of the sample is determined. If the solids content is known or determined to be less than 1 , stable, isotopically labeled analogs of the compounds of interest are added to a 5-mL sample. If the solids content of the sample is greater than 1 , 5 mL of reagent water and the labeled compounds are added to a 5-g aliquot of sample. The mixture is sonicated in a centrifuge vial with little or no headspace for 5 minutes. During this period the native analytes and labeled analogs will equilibrate between the solid and aqueous phases. In some cases, additional sonication will be necessary to establish equilibrium. The resulting suspension is centrifuged and the supernatant liquid analyzed. 2. 2. 2 One L or more of the aqueous solution ( or supernate ) is injected into the GC MS. The compounds are separated by the GC and detected by the MS ( References 2 and 3 ). The labeled compounds serve to correct the variability of the analytical technique. 2. 3 Identification of a pollutant ( qualitative analysis ) is performed by calibrating the GC MS with authentic standards and storing a mass spectrum and retention time for each compound in a user-created library. A compound is identified when its retention time and mass spectrum agree with the library retention time and spectrum. 2. 4 Quantitative analysis is performed in one of two ways by using extracted-ion current profile ( EICP ) areas. ( 1 ) For those compounds listed in Table 1 and Table 2, and for other compounds for which labeled analogs are available, the GC MS system is calibrated and the compound concentration is determined using an isotope dilution technique. ( 2 ) For those compounds listed in Table 1 and Table 2, and for other compounds for which authentic standards but no labeled compounds are available, the GC MS system is calibrated and the compound concentration is determined using an internal standard techni. . . This item ships from La Vergne,TN., RareBooksClub<