1、Designation:D642018Standard Test Method forDetermination of Gaseous Organic Compounds by DirectInterface Gas Chromatography-Mass Spectrometry1This standard is issued under the fixed designation D6420;the number immediately following the designation indicates the year oforiginal adoption or,in the ca
2、se of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method employs a direct interface gaschromatograph/mass spectrometer(GCMS)to identify
3、andquantify the 36 volatile organic compounds(or sub-set of thesecompounds)listed as follows.The individual Chemical Ab-stract Service(CAS)numbers are listed after each compound.Benzene-71432Methylene chloride-75092Bromodichloromethane-752741,1,2,2-Tetrachloroethane-79349Carbon disulfide-751501,1,1-
4、Trichloroethane-71556Chloroform-676631,1,2-Trichloroethane-79005Methyl iso-Butyl ketone-108101p-Xylene-106423Styrene-100425Bromomethane-74839Tetrachloroethylene-127184Carbon tetrachloride-56235Toluene-108883Chlorobenzene-108907Bromoform-75252c-1,3-Dichloropropene-10061015Vinyl acetate-1080541,2-Dich
5、loroethane-156592Vinyl chloride-750141,1-Dichloroethene-75354Chloromethane-74873t-1,2-Dichloroethene-156605cis-1,2-Dichloroethene-156592Methyl ethyl ketone-78933Dibromochloromethane-1244812-Hexanone-5917861,1-Dichloroethane-107062t-1,3-Dichloropropene-5427561,2-Dichloropropane-78875Trichloroethene-7
6、9016Ethylbenzene-100414m-Xylene-108383Ethyl chloride-75003o-Xylene-954761.2 The test method incorporates a performance-basedapproach,which validates each GCMS analysis by placingboundaries on the instrument response to gaseous internalstandards and their specific mass spectral relative abundance.Usi
7、ng this approach,the test method may be extended toanalyze other compounds.1.3 The test method provides on-site analysis of extracted,unconditioned,and unsaturated(at the instrument)gas samplesfrom stationary sources.Gas streams with high moisturecontent may require conditioning to prevent moisture
8、conden-sation within the instrument.For these samples,quality assur-ance(QA)requirements are provided in the test method tovalidate the analysis of polar,water-soluble compounds.1.4 The instrument range should be sufficient to measure thelisted volatile organic compounds from 150 ppb(v)to 100ppm(v),
9、using a full scan operation(between 45 and 300atomic mass units).The range may be extended to higher orlower concentrations using either of the following procedures:1.4.1 The initial three-point calibration concentrations andthe continuing calibration checks are adjusted to match thestack concentrat
10、ions,or1.4.2 The three-point calibration is extended to includeadditional concentrations to cover the measurement range.1.5 The minimum quantification level is 50%of the lowestcalibration concentration.Responses below this level areconsidered to be estimated concentrations,unless a calibrationstanda
11、rd check is conducted at a lower concentration todemonstrate linearity.The sensitivity of the GCMS measure-ment system for the individual target analytes depends upon:1.5.1 The specific instrument response for each target ana-lyte and the number of mass spectral quantification ionsavailable.1.5.2 Th
12、e amount of instrument noise,and1.5.3 The percent moisture content of the sample gas.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 This standard does not purport to address all of thesafety concerns,if any,associated wi
13、th its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Additional safety precautions are described in Section 9.1.8 This international standard was dev
14、eloped in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.1This test method i
15、s under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved Nov.1,2018.Published November 2018.Originallyapproved in 1999.Last previous edition approved in 2010 as D6420 99(20
16、10).DOI:10.1520/D6420-18.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 2.Referenced Documents2.1 ASTM Standards:2D1356 Ter
