ASTM D6420-99(2004)
(Test Method)Standard Test Method for Determination of Gaseous Organic Compounds by Direct Interface Gas Chromatography-Mass Spectrometry
Standard Test Method for Determination of Gaseous Organic Compounds by Direct Interface Gas Chromatography-Mass Spectrometry
SIGNIFICANCE AND USE
This field test method determines the mass concentration of VOHAPs (or any subset) listed in Section 1.
Multiplying the mass concentration by the effluent volumetric flow rate (see 2.2) yields mass emission rates.
This field test method employs the typical laboratory GCMS techniques and QA/QC procedures.
This field test method provides data with accuracy and precision similar to most laboratory GCMS instrumentation.
Note 1—Supporting data are available from ASTM Headquarters Request RR:_______.
SCOPE
1.1 This test method employs a direct interface gas chromatograph/mass spectrometer (GCMS) to identify and quantify the 36 volatile organic compounds (or sub-set of these compounds) listed as follows. The individual Chemical Abstract Service (CAS) numbers are listed after each compound.
Benzene-71432Methylene chloride-75092Bromodichloromethane-752741,1,2,2-Tetrachloroethane-79349Carbon disulfide-751501,1,1-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-Dichloroethane-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-79016Ethylbenzene-100414m-Xylene-108383Ethyl chloride-75003o-Xylene-95476
1.2 The test method incorporates a performance-based approach, which validates each GCMS analysis by placing boundaries on the instrument response to gaseous internal standards 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 from stationary sources. Gas streams with high moisture content may require conditioning to prevent moisture condensation within the instrument. For these samples, quality assurance (QA) requirements are provided in the test method to validate the analysis of polar, water-soluble compounds.
1.4 The instrument range should be sufficient to 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 concentrations using either of the following procedures:
1.4.1 The initial three-point calibration concentrations and the continuing calibration checks are adjusted to match the stack concentrations, or
1.4.2 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 below this level are considered to 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 each target analyte and the number of mass spectral quantification ions available.
1.5.2 The amount of instrument noise, and
1.5.3 The percent moisture content of the sample gas.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Additional safety precautions are described in Section .
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6420 – 99 (Reapproved 2004)
Standard Test Method for
Determination of Gaseous Organic Compounds by Direct
Interface Gas Chromatography-Mass Spectrometry
This standard is issued under the fixed designation D6420; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope ppm(v), using a full scan operation (between 45 and 300
atomic mass units). The range may be extended to higher or
1.1 This test method employs a direct interface gas
lower concentrations using either of the following procedures:
chromatograph/mass spectrometer (GCMS) to identify and
1.4.1 The initial three-point calibration concentrations and
quantify the 36 volatile organic compounds (or sub-set of these
the continuing calibration checks are adjusted to match the
compounds) listed as follows. The individual Chemical Ab-
stack concentrations, or
stract Service (CAS) numbers are listed after each compound.
1.4.2 The three-point calibration is extended to include
Benzene-71432 Methylene chloride-75092
additional concentrations to cover the measurement range.
Bromodichloromethane-75274 1,1,2,2-Tetrachloroethane-79349
Carbon disulfide-75150 1,1,1-Trichloroethane-71556
1.5 The minimum quantification level is 50 % of the lowest
Chloroform-67663 1,1,2-Trichloroethane-79005
calibration concentration. Responses below this level are
Methyl iso-Butyl ketone-108101 p-Xylene-106423
considered to be estimated concentrations, unless a calibration
Styrene-100425 Bromomethane-74839
Tetrachloroethylene-127184 Carbon tetrachloride-56235
standard check is conducted at a lower concentration to
Toluene-108883 Chlorobenzene-108907
demonstrate linearity. The sensitivity of the GCMS measure-
Bromoform-75252 c-1,3-Dichloropropene-10061015
ment system for the individual target analytes depends upon:
Vinyl acetate-108054 1,2-Dichloroethane-156592
Vinyl chloride-75014 1,1-Dichloroethene-75354
1.5.1 The specific instrument response for each target ana-
Chloromethane-74873 t-1,2-Dichloroethene-156605
lyte and the number of mass spectral quantification ions
cis-1,2-Dichloroethene-156592 Methyl ethyl ketone-78933
Dibromochloromethane-124481 2-Hexanone-591786 available.
1,1-Dichloroethane-107062 t-1,3-Dichloropropene-542756
1.5.2 The amount of instrument noise, and
1,2-Dichloropropane-78875 Trichloroethene-79016
1.5.3 The percent moisture content of the sample gas.
Ethylbenzene-100414 m-Xylene-108383
Ethyl chloride-75003 o-Xylene-95476 1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.2 The test method incorporates a performance-based ap-
responsibility of the user of this standard to establish appro-
proach, which validates each GCMS analysis by placing
priate safety and health practices and determine the applica-
boundaries on the instrument response to gaseous internal
bility of regulatory limitations prior to use. Additional safety
standards and their specific mass spectral relative abundance.
precautions are described in Section 9.
Using this approach, the test method may be extended to
analyze other compounds.
2. Referenced Documents
1.3 The test method provides on-site analysis of extracted,
2.1 ASTM Standards:
unconditioned, and unsaturated (at the instrument) gas samples
D1356 Terminology Relating to Sampling and Analysis of
from stationary sources. Gas streams with high moisture
Atmospheres
content may require conditioning to prevent moisture conden-
D3195 Practice for Rotameter Calibration
sation within the instrument. For these samples, quality assur-
2.2 EPA Test Methods:
ance (QA) requirements are provided in the test method to
Method 1–Sample and Velocity Traverses for Stationary
validate the analysis of polar, water-soluble compounds.
Sources
1.4 Theinstrumentrangeshouldbesufficienttomeasurethe
listed volatile organic compounds from 150 ppb(v) to 100
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This test method is under the jurisdiction of ASTM Committee D22 on contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Sampling and Analysis of Atmospheres and is the direct responsibility of Subcom- Standards volume information, refer to the standard’s Document Summary page on
mittee D22.03 on Ambient Atmospheres and Source Emissions. the ASTM website.
CurrenteditionapprovedOctober1,2004.PublishedDecember2004.Originally Code of Federal Regulations 40 CFR Part 60, Appendix A, available from
approved in 1999. Last previous edition approved in 1999 as D6420 - 99. DOI: Superintendent of Documents, U.S. Government Printing Office, Washington, DC
10.1520/D6420-99R04. 20402.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6420 – 99 (2004)
Method 2–Determination of Stack Gas Velocity and Volu- 5. Significance and Use
metric Flow Rate (Type S Pitot Tube)
5.1 This field test method determines the mass concentra-
Method 3–Gas Analysis for Carbon Dioxide, Oxygen, Ex-
tion of VOHAPs (or any subset) listed in Section 1.
cess Air, and Dry Molecular Weight
5.2 Multiplying the mass concentration by the effluent
Method 4–Determination of Moisture Content in Stack
volumetric flow rate (see 2.2) yields mass emission rates.
Gases
5.3 This field test method employs the typical laboratory
Method 624–Purgables
GCMS techniques and QA/QC procedures.
5.4 This field test method provides data with accuracy and
3. Terminology
precision similar to most laboratory GCMS instrumentation.
3.1 See Terminology D1356 for definition of terms used in
NOTE 1—Supporting data are available from ASTM Headquarters
this test method.
Request RR:_______.
3.2 Definitions of Terms Specific to This Standard:
6. Interferences
3.2.1 blank analysis, n—injecting zero air or nitrogen into
the GCMS to determine background levels of the target
6.1 Analytical Interferences—Analytical interferences oc-
analytes.
cur when chromatographic peak(s) and quantification ion(s)
3.2.2 CCC, n—continuing calibration check—injecting
overlap to such an extent that quantification of specific target
calibration gas standards into the GCMS to verify the calibra-
compounds is prohibited. The nature of the GCMS technique
tion status.
virtually eliminates these types of analytical interferences.
3.2.2.1 Discussion—The continuing calibration check is
However, compounds having very simple mass spectra (that is,
performed before each testing day, before resuming sampling
only one or two mass fragments) may be difficult to identify
afterinstrumentshutdownormalfunction,andbeforeresuming
positively.
sampling after 12 h of continuous instrument operation.
6.2 Sampling System Interferences—Samplingsysteminter-
3.2.3 quantification ion, n—a specific ion in the analytes
ferences occur when target analytes are not transported to the
mass spectrum that is used for quantification.
instrumentation or when compounds damage the measurement
3.2.4 system calibration, n—calibration obtained by inject-
system components. Water, reactive particulate matter, adsorp-
ing the calibration standard(s) through the entire sampling
tive sites within the sampling system components, and reactive
system.
gases are examples of such potential sampling system interfer-
3.2.5 system zero, n—zero obtained by injecting dry nitro-
ences. Specific provisions and performance criteria are in-
gen or zero gas through the entire sampling system to deter-
cluded in this test method to detect and prevent the presence of
mine the system background levels of the target analytes.
sampling system interferences.
4. Summary of Test Method
7. Apparatus
4.1 Analysis—Volatile Organic Hazardous Air Pollutants
7.1 Analytical Instrumentation:
(VOHAP) are analyzed using gas chromatography (GC) to
7.1.1 Gas Chromatograph/Mass Spectrometer (GCMS), ca-
separate the individual compounds and mass spectrometry
pable of separating the analyte mixture and detecting com-
(MS) to identify the compounds. The MS scans a defined mass
pounds in the 45 to 300 atomic mass unit (amu) range.
range (usually from 45 to 300 atomic mass units (amu) for
7.1.2 Personal Computer, with compatible GCMS software
combustion sources) to identify the specific fragments for each
for control of the GCMS and for data quantification.
molecule. The target analytes are identified positively by: (1)
7.2 Sampling System:
comparing eluting analyte GC peak retention times in the total
7.2.1 Sampling Probe, glass, stainless steel, or other appro-
ion chromatograph (TIC) to those contained in a three-point
priate material of sufficient length and physical integrity to
calibration, and (2) examining the mass spectral pattern of the
sustainheating,preventadsorptionofanalytes,andtoreachthe
eluted peaks. Internal standards are used to correct for
gas sampling point.
hardware-related errors such as different injection volumes,
7.2.2 Calibration Assembly, typically fabricated by user, to
operational temperature fluctuations, and electron multiplier
introduce calibration standards into the sampling system at the
drift.
probe outlet, upstream of the primary particulate filter, at the
4.2 Sampling—Samplesareextractedfromthestackorduct
same pressure and temperature as that of the effluent samples,
at a constant rate, filtered, conditioned (if required), and
with provisions for monitoring the sample pressure and tem-
transported to the GCMS for analysis. Calibration gases are
perature during continuing calibrations and effluent sampling.
introduced at the extractive probe outlet, upstream of the
7.2.3 Particulate Filters, rated at 0.3 µm, placed immedi-
primaryparticulatefilter.Allsampleextractioncomponentsare
ately after the heated probe and after the sample condenser
maintained at temperatures that prevent moisture condensation
system.
within the measurement system components.
7.2.4 Pump, leak-free, with heated head, capable of main-
taining 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, tetrafluo-
Code of Federal Regulations 40 CFR Part 136, Appendix A, available from
rocarbon polymer, or other material that minimizes adsorption
Superintendent of Documents, U.S. Government Printing Office, Washington, DC
20402. of analytes, of minimal length.
D6420 – 99 (2004)
7.2.6 Sample Condenser System,arefrigerationunitcapable 8. Reagents and Materials
of reducing and removing the moisture of the sample gas to a
8.1 Calibration Gases, gas standards (in nitrogen balance or
level acceptable for sample injection.
other inert gas) for those compounds identified in Section 1,
7.2.7 Sample Flow Rotameters, capable of withstanding
certified by the manufacturer to be accurate to 5 % or better,
sample gas conditions, calibrated in accordance with Practice
used for the initial and continuing calibrations.
D3195.
NOTE 2—The analytical accuracy of the calibration standards must be
7.2.8 Sample Transfer Line, to transport sample from
known. The analytical accuracy for gas mixtures may be concentration
sample interface to GCMS, heated to prevent sample conden-
dependent.
sation and fabricated of stainless steel, tetrafluorocarbon poly-
8.2 Internal Standards, manufacturer-certified mixtures for
mer, or other material to minimize adsorption of analytes, of
co-injection with sample gas.
minimal length.
8.3 High Purity (HP) Nitrogen or Zero Air, for purging
7.3 Auxiliary Equipment:
sample lines and sampling system components, dilutions, and
7.3.1 Calibration Gas Manifold, capable of delivering ni-
blank runs.
trogen or calibration gases through sampling system or directly
to the instrumentation, with provisions to provide for accurate
9. Hazards
dilution of the calibration gases as necessary. See Fig. 1 for an
9.1 Target Analytes—Many of the compounds listed in
example schematic.
Section 1 are toxic and carcinogenic. Therefore, avoid expo-
7.3.2 Mass Flow Meters or Controllers, with a stated
sure to these chemicals. Calibration standards are contained in
accuracy and calibrated range (62 % of scale from 0 to 500
compressed gas cylinders; exercise appropriate safety precau-
mL/min or 0 to 5 L/min).
tions to avoid accidents in their transport and use.
7.3.3 Digital Bubble Meter (or equivalent), having a NIST-
9.2 Sampling Location—This test method may involve
traceable calibration and accuracy of 62 % of reading, with an
sampling locations with high positive or negative pressures,
adequate range to calibrate mass flow meters or controllers and
high temperatures, elevated heights, or high concentrations of
rotametersatthespecificflowrates(within 610 %)requiredto
hazardous or toxic pollutants.
perform the test method.
9.3 Mobile or Remote Laboratory—To avoid exposure to
7.3.4 Tubing, tetrafluorocarbon polymer (or other mate- hazardous pollutants and to protect personnel in the laboratory,
rial), of suitable diameter and length to connect cylinder
perform a leak check of the sampling system and inspect the
regulators and minimize the adsorption of analytes on the sample exhaust equipment before sampling the calibration
tubing surface.
standards or effluent. Properly vent the exhaust gases.
7.3.5 Tubing, 316 stainless steel (or other material), of
10. Calibration and Standardization
suitable diameter and length for heated connections.
7.3.6 Gas Regulators, appropriate for individual gas cylin- 10.1 Calibration Standards—Because of the incompatibil-
ders, constructed of materials that minimize adsorption of ity of some target compounds, many gas blends at each
analytes. concentration may be needed to construct a calibration curve
FIG. 1 Example Direct Interface GCMS Measurement System
D6420 – 99 (2004)
TABLE 2 Relative Ion Abundance Criteria for
for all of the 36 target analytes listed in 1.1. Obtain or generate
Bromofluorobenzene
calibration standards of each target compound at nominal
Mass Fragment Ion Abundance Criteria
concentrations of 300 ppb(v), 1 ppm(v), and 10 ppm(v) by
50 15-40 %
either of the following options:
75 30-60 %
10.1.1 Option 1—Obtain calibration gas standards for the
95 Base peak
target compounds at the three specified nominal concentra-
96 5-9 % of mass 95
tions. 173 <2 % of mass 174
174 >50 % of mass 95
10.1.2 Option 2—Obtain 10 ppm(v) calibration standards
175 5-9 % of mass 174
for the target analytes. Then successively dilute the 10 ppm(v)
176 >95 % but <101 % of mass 174
177 5-9 %
...
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