ASTM D6550-05
(Test Method)Standard Test Method for Determination of Olefin Content of Gasolines by Supercritical-Fluid Chromatography
Standard Test Method for Determination of Olefin Content of Gasolines by Supercritical-Fluid Chromatography
SIGNIFICANCE AND USE
Gasoline-range olefinic hydrocarbons have been demonstrated to contribute to photochemical reactions in the atmosphere, which result in the formation of photochemical smog in susceptible urban areas.
The California Air Resources Board (CARB) has specified a maximum allowable limit of total olefins in motor gasoline. This necessitates an appropriate analytical test method for determination of total olefins to be used both by regulators and producers.
This test method compares favorably with Test Method D 1319 (FIA) for the determination of total olefins in motor gasolines. It does not require any sample preparation, has a comparatively short analysis time of about 10 min, and is readily automated. Alternative methods for determination of olefins in gasoline include Test Methods D 6293 and D 6296.
SCOPE
1.1 This test method covers the determination of the total amount of olefins in blended motor gasolines and gasoline blending stocks by supercritical-fluid chromatography (SFC). Results are expressed in terms of mass % olefins. The application range is from 1 to 25 mass % total olefins.
1.2 This test method can be used for analysis of commercial gasolines, including those containing varying levels of oxygenates, such as methyl tert/butyl ether (MTBE), diisopropyl ether (DIPE), methyl tert/amyl ether (TAME), and ethanol, without interference.Note 1
This test method has not been designed for the determination of the total amounts of saturates, aromatics, and oxygenates.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D6550 – 05
Standard Test Method for
Determination of Olefin Content of Gasolines by
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Supercritical-Fluid Chromatography
This standard is issued under the fixed designation D6550; 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* Naphthene, Aromatic(O-PONA) Hydrocarbon Types in
Low-Olefin Spark Ignition Engine Fuels by Gas Chroma-
1.1 This test method covers the determination of the total
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tography
amount of olefins in blended motor gasolines and gasoline
D6296 Test Method for Total Olefins in Spark-ignition
blending stocks by supercritical-fluid chromatography (SFC).
Engine Fuels by Multidimensional Gas Chromatography
Results are expressed in terms of mass % olefins. The
D6299 Practice for Applying Statistical Quality Assurance
application range is from 1 to 25 mass % total olefins.
and Control Charting Techniques to Evaluate Analytical
1.2 This test method can be used for analysis of commercial
Measurement System Performance
gasolines,includingthosecontainingvaryinglevelsofoxygen-
ates, such as methyl tert/butyl ether (MTBE), diisopropyl ether
3. Terminology
(DIPE), methyl tert/amyl ether (TAME), and ethanol, without
3.1 Definitions of Terms Specific to This Standard:
interference.
3.1.1 critical pressure, n—the pressure needed to condense
NOTE 1—This test method has not been designed for the determination
a gas to a liquid at the critical temperature.
of the total amounts of saturates, aromatics, and oxygenates.
3.1.2 critical temperature, n—the highest temperature at
1.3 The values stated in SI units are to be regarded as the
which a gaseous fluid can be condensed to a liquid by means
standard. The values given in parentheses are for information
of compression.
only.
3.1.3 supercritical fluid, n—a fluid maintained above its
1.4 This standard does not purport to address all of the
critical temperature and critical pressure.
safety concerns, if any, associated with its use. It is the
3.1.4 supercritical-fluid chromatography (SFC), n—a type
responsibility of the user of this standard to establish appro-
of chromatography that employs a supercritical fluid as the
priate safety and health practices and determine the applica-
mobile phase.
bility of regulatory limitations prior to use.
4. Summary of Test Method
2. Referenced Documents
4.1 A small aliquot of the fuel sample is injected onto a set
2
2.1 ASTM Standards:
of two chromatographic columns connected in series and
D1319 Test Method for Hydrocarbon Types in Liquid
transported using supercritical carbon dioxide (CO)asthe
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Petroleum Products by Fluorescent Indicator Adsorption
mobile phase. The first column is packed with high-surface-
D4052 Test Method for Density, Relative Density, and API
area silica particles. The second column contains either high-
Gravity of Liquids by Digital Density Meter
surface-area silica particles loaded with silver ions or strong-
D5186 Test Method for Determination of the Aromatic
cation-exchange material loaded with silver ions.
ContentandPolynuclearAromaticContentofDieselFuels
4.2 Two switching valves are used to direct the different
and Aviation Turbine Fuels By Supercritical Fluid Chro-
classes of components through the chromatographic system to
matography
the detector. In a forward-flow mode, saturates (normal and
D6293 Test Method for Oxygenates and Paraffin, Olefin,
branchedalkanes,cyclicalkanes)passthroughbothcolumnsto
the detector, while the olefins are trapped on the silver-loaded
column and the aromatics and oxygenates are retained on the
1
This test method is under the jurisdiction of ASTM Committee D02 on
silica column. Aromatic compounds and oxygenates are sub-
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
sequently eluted from the silica column to the detector in a
D02.04 on Hydrocarbon Analysis.
Current edition approved Nov. 1, 2005. Published November 2005. Originally back-flush mode. Finally, the olefins are back-flushed from the
approved in 2000. Last previous edition approved in 2000 as D6550–00. DOI:
silver-loaded column to the detector.
10.1520/D6550-05.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
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Standards volume information, refer to the standard’s Document Summary page on Withdrawn. The last approved version of this historical standard is referenced
the ASTM website. on www.astm.org.
*A Summary of Changes section appears at the end of this standard.
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