ASTM D6729-20

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6729 − 20
Standard Test Method for
Determination of Individual Components in Spark Ignition
Engine Fuels by 100 Metre Capillary High Resolution Gas
1
Chromatography
This standard is issued under the fixed designation D6729; 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* laboratory cooperative study, this procedure is applicable to
samples containing less than 25 % mass of olefins. However,
1.1 This test method covers the determination of individual
some interfering coelution with the olefins above C is
7
hydrocarbon components of spark-ignition engine fuels and
possible, particularly if blending components or their higher
their mixtures containing oxygenate blends (MTBE, ETBE,
boiling cuts such as those derived from fluid catalytic cracking
ethanol, and so forth) with boiling ranges up to 225 °C. Other
(FCC) are analyzed, and the total olefin content may not be
light liquid hydrocarbon mixtures typically encountered in
accurate. Caution should also be exercised when analyzing
petroleum refining operations, such as blending stocks
olefin-free samples using this test method as some of the
(naphthas, reformates, alkylates, and so forth) may also be
paraffins may be reported as olefins since analysis is based
analyzed; however, statistical data was obtained only with
purely on retention times of the eluting components.
blended spark-ignition engine fuels.
1.4.1 Total olefins in the samples may be obtained or
1.2 Based on the cooperative study results, individual com-
confirmed, or both, if necessary, by Test Method D1319
ponent concentrations and precision are determined in the
(percent volume) or other test methods, such as those based on
range of 0.01 % mass to approximately 30 % mass. The
multidimensional PONA type of instruments (Test Method
procedure may be applicable to higher and lower concentra-
D6839).
tions for the individual components; however, the user must
1.5 If water is or is suspected of being present, its concen-
verify the accuracy if the procedure is used for components
tration may be determined, if desired, by the use of Test
with concentrations outside the specified ranges.
Method D1744, or equivalent. Other compounds containing
1.3 The test method also determines methanol, ethanol,
oxygen, sulfur, nitrogen, and so forth, may also be present, and
t-butanol, methyl t-butyl ether (MTBE), ethyl t-butyl ether
may co-elute with the hydrocarbons. If determination of these
(ETBE), t-amyl methyl ether (TAME) in spark ignition engine
specific compounds is required, it is recommended that test
fuels in the concentration range of 1 % mass to 30 % mass.
methods for these specific materials be used, such as Test
However, the cooperative study data provided sufficient statis-
Methods D4815 and D5599 for oxygenates, and D5623 for
tical data for MTBE only.
sulfur compounds, or equivalent.
1.4 Although a majority of the individual hydrocarbons
1.6 Annex A1 of this test method compares results of the
present are determined, some co-elution of compounds is
test procedure with other test methods for selected
encountered. If this test method is utilized to estimate bulk
components, including olefins, and several group types for
hydrocarbon group-type composition (PONA) the user of such
several interlaboratory cooperative study samples. Although
data should be cautioned that some error will be encountered
benzene,toluene,andseveraloxygenatesaredetermined,when
due to co-elution and a lack of identification of all components
doubtful as to the analytical results of these components,
present. Samples containing significant amounts of olefinic or
confirmatory analyses can be obtained by using specific test
naphthenic (for example, virgin naphthas), or both, constitu-
methods.
ents above n-octane may reflect significant errors in PONA
1.7 The values stated in SI units are to be regarded as
type groupings. Based on the gasoline samples in the inter-
standard. No other units of measurement are included in this
standard.
1
1.8 This standard does not purport to address all of the
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
safety concerns, if any, associated with its use. It is the
Subcommittee D02.04.0L on Gas Chromatography Methods.
responsibility of the user of this standard to establish appro-
Current edition approved June 1, 2020. Published
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