1、Designation: D6420 99 (Reapproved 2010)D6420 18Standard 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 ofo
2、riginal adoption or, in the case 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 gas chromatograp
3、h/mass spectrometer (GCMS) to identify and quantify the 36volatile organic compounds (or sub-set of these compounds) listed as follows. The individual Chemical Abstract Service (CAS)numbers are listed after each compound.Benzene-71432 Methylene chloride-75092Bromodichloromethane-75274 1,1,2,2-Tetrac
4、hloroethane-79349Carbon disulfide-75150 1,1,1-Trichloroethane-71556Chloroform-67663 1,1,2-Trichloroethane-79005Methyl iso-Butyl ketone-108101 p-Xylene-106423Styrene-100425 Bromomethane-74839Tetrachloroethylene-127184 Carbon tetrachloride-56235Toluene-108883 Chlorobenzene-108907Bromoform-75252 c-1,3-
5、Dichloropropene-10061015Vinyl acetate-108054 1,2-Dichloroethane-156592Vinyl chloride-75014 1,1-Dichloroethene-75354Chloromethane-74873 t-1,2-Dichloroethene-156605cis-1,2-Dichloroethene-156592 Methyl ethyl ketone-78933Dibromochloromethane-124481 2-Hexanone-5917861,1-Dichloroethane-107062 t-1,3-Dichlo
6、ropropene-5427561,2-Dichloropropane-78875 Trichloroethene-79016Ethylbenzene-100414 m-Xylene-108383Ethyl chloride-75003 o-Xylene-954761.2 The test method incorporates a performance-based approach, which validates each GCMS analysis by placing boundarieson the instrument response to gaseous internal s
7、tandards and their specific mass spectral relative abundance. Using this approach,the test method may be extended to analyze other compounds.1.3 The test method provides on-site analysis of extracted, unconditioned, and unsaturated (at the instrument) gas samples fromstationary sources. Gas streams
8、with high moisture content may require conditioning to prevent moisture condensation within theinstrument. For these samples, quality assurance (QA) requirements are provided in the test method to validate the analysis ofpolar, water-soluble compounds.1.4 The instrument range should be sufficient to
9、 measure the listed volatile organic compounds from 150 ppb(v) to 100 ppm(v),using a full scan operation (between 45 and 300 atomic mass units). The range may be extended to higher or lower concentrationsusing either of the following procedures:1.4.1 The initial three-point calibration concentration
10、s and the continuing calibration checks are adjusted to match the stackconcentrations, or1.4.2 The three-point calibration is extended to include additional concentrations to cover the measurement range.1.5 The minimum quantification level is 50 % of the lowest calibration concentration. Responses b
11、elow this level are consideredto be estimated concentrations, unless a calibration standard check is conducted at a lower concentration to demonstrate linearity.The sensitivity of the GCMS measurement system for the individual target analytes depends upon:1.5.1 The specific instrument response for e
12、ach target analyte and the number of mass spectral quantification ions available.1.5.2 The amount of instrument noise, and1.5.3 The percent moisture content of the sample gas.1 This test method is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcomm
13、ittee D22.03 on Ambient Atmospheresand Source Emissions.Current edition approved Oct. 1, 2010Nov. 1, 2018. Published November 2010November 2018. Originally approved in 1999. Last previous edition approved in 20042010as D6420 99 (2004).(2010). DOI: 10.1520/D6420-99R10.10.1520/D6420-18.This document i
14、s not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as approp
15、riate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States11.6 The values stated in SI units are to be regarded as standar
16、d. No other units of measurement are included in this standard.1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental pract
17、ices and determine theapplicability of regulatory limitations prior to use. Additional safety precautions are described in Section 9.1.8 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for
18、the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.D6420 1822. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis of AtmospheresD3195 Practice for Rotameter
19、Calibration2.2 EPA Test Methods:Method 1Sample1 Sample and Velocity Traverses for Stationary Sources3Method 2Determination2 Determination of Stack Gas Velocity and Volumetric Flow Rate (Type S Pitot Tube)3Method 3Gas3 Gas Analysis for Carbon Dioxide, Oxygen, Excess Air, and Dry Molecular Weight3Meth
20、od 4Determination4 Determination of Moisture Content in Stack Gases3Method 624Purgables624 Purgables43. Terminology3.1 DefinitionsSee TerminologyFor definitions D1356 for definition of terms used in this test method.method, seeTerminology D1356.3.2 Definitions of Terms Specific to This Standard:3.2.
21、1 blank analysis, ninjecting zero air or nitrogen into the GCMS to determine background levels of the target analytes.3.2.2 CCC, ncontinuing calibration checkinjecting calibration gas standards into the GCMS to verify the calibration status.3.2.2.1 DiscussionThe continuing calibration check is perfo
22、rmed before each testing day, before resuming sampling after instrument shutdown ormalfunction, and before resuming sampling after 12 h of continuous instrument operation.3.2.3 quantification ion, na specific ion in the analytes mass spectrum that is used for quantification.3.2.4 system calibration,
23、 ncalibration obtained by injecting the calibration standard(s) through the entire sampling system.3.2.5 system zero, nzero obtained by injecting dry nitrogen or zero gas through the entire sampling system to determine thesystem background levels of the target analytes.4. Summary of Test Method4.1 A
24、nalysisVolatile Organic Hazardous Air Pollutantsorganic hazardous air pollutants (VOHAP) are analyzed using gaschromatography (GC) to separate the individual compounds and mass spectrometry (MS) to identify the compounds.The MS scansa defined mass range (usually from 45 to 300 atomic mass units (amu
25、) for combustion sources) to identify the specific fragmentsfor each molecule. The target analytes are identified positively by: (1) comparing eluting analyte GC peak retention times in thetotal ion chromatograph (TIC) to those contained in a three-point calibration, and (2) examining the mass spect
26、ral pattern of theeluted peaks. Internal standards are used to correct for hardware-related errors such as different injection volumes, operationaltemperature fluctuations, and electron multiplier drift.4.2 SamplingSamples are extracted from the stack or duct at a constant rate, filtered, conditione
27、d (if required), and transportedto the GCMS for analysis. Calibration gases are introduced at the extractive probe outlet, upstream of the primary particulate filter.All sample extraction components are maintained at temperatures that prevent moisture condensation within the measurementsystem compon
28、ents.5. Significance and Use5.1 This field test method determines the mass concentration of VOHAPs (or any subset) listed in Section 1.5.2 Multiplying the mass concentration by the effluent volumetric flow rate (see 2.2) yields mass emission rates.5.3 This field test method employs the typical labor
29、atory GCMS techniques and QA/QC procedures.QA/quality control (QC)procedures in common application.5.4 This field test method provides data with accuracy and precision similar to most laboratory GCMS instrumentation.NOTE 1Supporting data are available from ASTM Headquarters Request RR:_.2 For refere
30、ncedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on the ASTM website.3 Code of Federal Regulations 40 CFR Part 60, Appendix A, availa
31、ble from Superintendent of Documents, U.S. Government Printing Office, Washington, DC20402.Superintendent of Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http:/www.access.gpo.gov.4 Code of Federal Regulations 40 CFR Part 136, Appendix A, available from Superintendent of Documents, U
32、.S. Government Printing Office, Washington, DC20402.Superintendent of Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http:/www.access.gpo.gov.D6420 1836. Interferences6.1 Analytical InterferencesAnalytical interferences occur when chromatographic peak(s) and quantification ion(s) over
33、lap tosuch an extent that quantification of specific target compounds is prohibited. The nature of the GCMS technique virtuallyeliminates these types of analytical interferences. However, compounds having very simple mass spectra (that is, only one or twomass fragments) may be difficult to identify
34、positively.6.2 Sampling System InterferencesSampling system interferences occur when target analytes are not transported to theinstrumentation or when compounds damage the measurement system components. Water, reactive particulate matter, adsorptivesites within the sampling system components, and re
35、active gases are examples of such potential sampling system interferences.Specific provisions and performance criteria are included in this test method to detect and prevent the presence of sampling systeminterferences.7. Apparatus7.1 Analytical Instrumentation:7.1.1 Gas Chromatograph/Mass Spectrome
36、ter (GCMS), capable of separating the analyte mixture and detecting compounds inthe 45 to 300 atomic mass unit (amu) range.7.1.2 Personal Computer, with compatible GCMS software for control of the GCMS and for data quantification.7.2 Sampling System:7.2.1 Sampling Probe, glass, stainless steel, or o
37、ther appropriate material of sufficient length and physical integrity to sustainheating, prevent adsorption of analytes, and to reach the gas sampling point.7.2.2 Calibration Assembly, typically fabricated by user, to introduce calibration standards into the sampling system at the probeoutlet, upstr
38、eam of the primary particulate filter, at the same pressure and temperature as that of the effluent samples, withprovisions for monitoring the sample pressure and temperature during continuing calibrations and effluent sampling.7.2.3 Particulate Filters, rated at 0.3 m, placed immediately after the
39、heated probe and after the sample condenser system.7.2.4 Pump, leak-free, with heated head, capable of maintaining an adequate sample flow rate (at least 1.5 L/min).7.2.5 Sampling Line, of suitable internal diameter, heated to prevent sample condensation, made of stainless steel,tetrafluorocarbon po
40、lymer, or other material that minimizes adsorption of analytes, of minimal length.7.2.6 Sample Condenser System, a refrigeration unit capable of reducing and removing the moisture of the sample gas to a levelacceptable for sample injection.7.2.7 Sample Flow Rotameters, capable of withstanding sample
41、 gas conditions, calibrated in accordance with Practice D3195.7.2.8 Sample Transfer Line, to transport sample from sample interface to GCMS, heated to prevent sample condensation andfabricated of stainless steel, tetrafluorocarbon polymer, or other material to minimize adsorption of analytes, of min
42、imal length.7.3 Auxiliary Equipment:7.3.1 Calibration Gas Manifold, capable of delivering nitrogen or calibration gases through sampling system or directly to theinstrumentation, with provisions to provide for accurate dilution of the calibration gases as necessary. See Fig. 1 for an exampleFIG. 1 E
43、xample Direct Interface GCMS Measurement SystemD6420 184schematic.7.3.2 Mass Flow Meters or Controllers, with a stated accuracy and calibrated range (62 % of scale from 0 to 500 mL/min or0 to 5 L/min).7.3.3 Digital Bubble Meter (or equivalent), having a NIST-traceable calibration and accuracy of 62
44、% of reading, with anadequate range to calibrate mass flow meters or controllers and rotameters at the specific flow rates (within 610 %) required toperform the test method.7.3.4 Tubing, tetrafluorocarbon polymer (or other material), of suitable diameter and length to connect cylinder regulators and
45、minimize the adsorption of analytes on the tubing surface.7.3.5 Tubing, 316 stainless steel (or other material), of suitable diameter and length for heated connections.7.3.6 Gas Regulators, appropriate for individual gas cylinders, constructed of materials that minimize adsorption of analytes.8. Rea
46、gents and Materials8.1 Calibration Gases, gas standards (in nitrogen balance or other inert gas) for those compounds identified in Section 1,certified by the manufacturer to be accurate to 5 % or better, used for the initial and continuing calibrations.NOTE 1The analytical accuracy of the calibratio
47、n standards must be known. The analytical accuracy for gas mixtures may be concentrationdependent.8.2 Internal Standards, manufacturer-certified mixtures for co-injection with sample gas.8.3 High Purity (HP) Nitrogen or ZeroAir, for purging sample lines and sampling system components, dilutions, and
48、 blank runs.9. Hazards9.1 Target AnalytesMany of the compounds listed in Section 1 are toxic and carcinogenic. Therefore, avoid exposure to thesechemicals. Calibration standards are contained in compressed gas cylinders; exercise appropriate safety precautions to avoidaccidents in their transport an
49、d use.9.2 Sampling LocationThis test method may involve sampling locations with high positive or negative pressures, hightemperatures, elevated heights, or high concentrations of hazardous or toxic pollutants.9.3 Mobile or Remote LaboratoryTo avoid exposure to hazardous pollutants and to protect personnel in the laboratory,perform a leak check of the sampling system and inspect the sample exhaust equipment before sampling the calibration standardsor effluent. Properly vent the exhaust gases.10. Calibration and Standardization10.1 Calibration Sta
