ASTM D1945-03

Standard Test Method for Analysis of Natural Gas by Gas Chromatography

SIGNIFICANCE AND USE
This test method is of significance for providing data for calculating physical properties of the sample, such as heating value and relative density, or for monitoring the concentrations of one or more of the components in a mixture.
SCOPE
1.1 This test method covers the determination of the chemical composition of natural gases and similar gaseous mixtures within the range of composition shown in Table 1. This test method may be abbreviated for the analysis of lean natural gases containing negligible amounts of hexanes and higher hydrocarbons, or for the determination of one or more components, as required.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 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.

General Information

• Status: Historical
• Publication Date: 09-May-2003
• ICS: 75.060 - Natural gas
• Technical Committee: D03 - Gaseous Fuels

Relations

• Replaces: ASTM D1945-96(2001) - Standard Test Method for Analysis of Natural Gas by Gas Chromatography
• Effective Date: 10-May-2003
• Replaced By: ASTM D1945-03(2010) - Standard Test Method for Analysis of Natural Gas by Gas Chromatography
• Effective Date: 01-Jan-2010
• Referred By: ASTM D5504-20 - Standard Test Method for Determination of Sulfur Compounds in Natural Gas and Gaseous Fuels by Gas Chromatography and Chemiluminescence
• Effective Date: 10-May-2003
• Referred By: ASTM D7800/D7800M-23 - Standard Test Method for Determination of Elemental Sulfur in Natural Gas
• Effective Date: 10-May-2003
• Referred By: ASTM D7164-21 - Standard Practice for On-line/At-line Heating Value Determination of Gaseous Fuels by Gas Chromatography
• Effective Date: 10-May-2003
• Referred By: ASTM D3588-98(2017)e1 - Standard Practice for Calculating Heat Value, Compressibility Factor, and Relative Density of Gaseous Fuels
• Effective Date: 10-May-2003
• Referred By: ASTM D6332-12(2021) - Standard Guide for Testing Systems for Measuring Dynamic Responses of Carbon Monoxide Detectors to Gases and Vapors
• Effective Date: 10-May-2003
• Referred By: ASTM D7940-21 - Standard Practice for Analysis of Liquefied Natural Gas (LNG) by Fiber-Coupled Raman Spectroscopy
• Effective Date: 10-May-2003
• Referred By: ASTM D6228-19 - Standard Test Method for Determination of Sulfur Compounds in Natural Gas and Gaseous Fuels by Gas Chromatography and Flame Photometric Detection
• Effective Date: 10-May-2003
• Referred By: ASTM D8080-21 - Standard Specification for Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG) Used as a Motor Vehicle Fuel
• Effective Date: 10-May-2003
• Referred By: ASTM D8488-22 - Standard Test Method for Determination of Hydrogen Sulfide (H<inf>2</inf>S) in Natural Gas by Tunable Diode Laser Spectroscopy (TDLAS)
• Effective Date: 10-May-2003
• Referred By: ASTM D6968-03(2015) - Standard Test Method for Simultaneous Measurement of Sulfur Compounds and Minor Hydrocarbons in Natural Gas and Gaseous Fuels by Gas Chromatography and Atomic Emission Detection
• Effective Date: 10-May-2003
• Referred By: ASTM D7165-22 - Standard Practice for Gas Chromatograph Based On-line/At-line Analysis for Sulfur Content of Gaseous Fuels
• Effective Date: 10-May-2003
• Referred By: ASTM D7833-20 - Standard Test Method for Determination of Hydrocarbons and Non-Hydrocarbon Gases in Gaseous Mixtures by Gas Chromatography
• Effective Date: 10-May-2003
• Referred By: ASTM D8487-23 - Standard Specification for Natural Gas, Hydrogen Blends for Use as a Motor Vehicle Fuel
• Effective Date: 10-May-2003

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: D1945 – 03
Standard Test Method for
1
Analysis of Natural Gas by Gas Chromatography
This standard is issued under the fixed designation D1945; 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.
TABLE 1 Natural Gas Components and Range of
1. Scope*
Composition Covered
1.1 This test method covers the determination of the chemi-
Component Mol%
cal composition of natural gases and similar gaseous mixtures
Helium 0.01 to 10
within the range of composition shown in Table 1. This test
Hydrogen 0.01 to 10
method may be abbreviated for the analysis of lean natural
Oxygen 0.01 to 20
gases containing negligible amounts of hexanes and higher Nitrogen 0.01 to 100
Carbon dioxide 0.01 to 20
hydrocarbons, or for the determination of one or more compo-
Methane 0.01 to 100
nents, as required.
Ethane 0.01 to 100
Hydrogen sulfide 0.3 to 30
1.2 The values stated in SI units are to be regarded as the
Propane 0.01 to 100
standard. The values given in parentheses are for information
Isobutane 0.01 to 10
only.
n-Butane 0.01 to 10
Neopentane 0.01 to 2
1.3 This standard does not purport to address all of the
Isopentane 0.01 to 2
safety concerns, if any, associated with its use. It is the
n-Pentane 0.01 to 2
responsibility of the user of this standard to establish appro-
Hexane isomers 0.01 to 2
Heptanes+ 0.01 to 1
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents composition of the sample is calculated by comparing either
2
the peak heights, or the peak areas, or both, with the corre-
2.1 ASTM Standards:
sponding values obtained with the reference standard.
D2597 Test Method for Analysis of Demethanized Hydro-
carbon Liquid Mixtures Containing Nitrogen and Carbon
4. Significance and Use
3
Dioxide by Gas Chromatography
4.1 This test method is of significance for providing data for
D3588 Practice for Calculating HeatValue, Compressibility
4
calculating physical properties of the sample, such as heating
Factor, and Relative Density of Gaseous Fuels
value and relative density, or for monitoring the concentrations
E260 Practice for Packed Column Gas Chromatography
of one or more of the components in a mixture.
3. Summary of Test Method
5. Apparatus
3.1 Components in a representative sample are physically
5.1 Detector—The detector shall be a thermal-conductivity
separated by gas chromatography (GC) and compared to
type, or its equivalent in sensitivity and stability. The thermal
calibration data obtained under identical operating conditions
conductivity detector must be sufficiently sensitive to produce
from a reference standard mixture of known composition. The
a signal of at least 0.5 mV for 1 mol % n-butane in a 0.25-mL
numerous heavy-end components of a sample can be grouped
sample.
into irregular peaks by reversing the direction of the carrier gas
5.2 Recording Instruments—Either strip-chart recorders or
through the column at such time as to group the heavy ends
electronic integrators, or both, are used to display the separated
eitherasC andheavier,C andheavier,orC andheavier.The
5 6 7
components. Although a strip-chart recorder is not required
when using electronic integration, it is highly desirable for
evaluation of instrument performance.
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ThistestmethodisunderthejurisdictionofASTMCommitteeD03onGaseous
5.2.1 The recorder shall be a strip-chart recorder with a
Fuels and is the direct responsibility of Subcommittee D03.07 on Analysis of
full-range scale of 5 mVor less (1 mVpreferred).The width of
Chemical Composition of Gaseous Fuels.
the chart shall be not less than 150 mm. A maximum pen
Current edition approved May 10, 2003. Published July 2003. Originally
approved in 1962. Last previous edition approved in 2001 as D1945–96(2001).
response time of2s(1s preferred) and a minimum chart speed
DOI: 10.1520/D1945-03.
of 10 mm/min shall be required. Faster speeds up to 100
2
Annual Book of ASTM Standards, Vol 05.02.
3
mm/min are desirable if the chromatogram is to be interpreted
Annual Book of ASTM Standards, Vol 05.05.
4
Annual Book of ASTM Standards, Vol 14.02. using manual methods to obtain areas.
*A Summary of Changes section appears at the end of this standard.
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D1945 – 03
5.2.2 Electronic or Computing Integrators—Proof of sepa- 5.5.2 Temperature Programming—Temperature program-
ration and response equivalent to that for a recorder is required ming may be used, a
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