ASTM D6293-98
(Test Method)Standard Test Method for Oxygenates and Paraffin, Olefin, Naphthene, Aromatic (O-PONA) Hydrocarbon Types in Low-Olefin Spark Ignition Engine Fuels by Gas Chromatography
Standard Test Method for Oxygenates and Paraffin, Olefin, Naphthene, Aromatic (O-PONA) Hydrocarbon Types in Low-Olefin Spark Ignition Engine Fuels by Gas Chromatography
SCOPE
1.1 This test method provides for the quantitative determination of oxygenates, paraffins, olefins, naphthenes, and aromatics in low-olefin spark-ignition engine fuels by multi-dimensional gas chromatography. Each hydrocarbon type can be reported either by carbon number (Note 1) or as a total through C10, except for olefins, which can only be reported through C9. Higher boiling hydrocarbons cannot be reported by type and are reported as a composite group. The lower limit of detection for a single hydrocarbon component or carbon number type is 0.05 mass %. Note 1-There can be an overlap between the C9 and C10 aromatics; however, the total is accurate. Isopropyl benzene is resolved from the C8 aromatics and is included with the other C9 aromatics. Naphthalene is determined with the C11 components.
1.2 This test method is applicable for total olefins in the range from 0.05 to 13 mass %. The test method can quantitatively determine olefins in samples where the olefin concentration does not exceed 0.6% C4 or 4.0% C5 or 4.5% of the combined C4 and C5. Although the precision for benzene was determined in the range from 0.3 to 1.0 mass %, this test method can be used to determine benzene concentrations up to 5.0 mass %.
1.3 This test method is not intended to determine individual hydrocarbon components except for those hydrocarbon types for which there is only one component within a carbon number. Individually determined hydrocarbons are benzene, toluene, cyclopentane, propane, propylene, and cyclopentene.
1.4 Precision data has only been obtained on samples containing MTBE. Application of this test method to determine other oxygenates shall be verified in the user's laboratory. Methanol cannot be determined and shall be quantitated by an appropriate oxygenate method such as Test Method D 4815 or D 5599. Methanol is fully resolved and does not interfere with the dertermination of other components or groups.
1.5 Although specifically written for spark-ignition engine fuels containing oxygenates, this test method can also be applied to other hydrocarbon streams having similar boiling ranges, such as naphthas and reformates.
1.6 The values stated in SI units are to be regarded as the standard.
1.7 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.
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Standards Content (Sample)
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An American National Standard
Designation: D 6293 – 98
Standard Test Method for
Oxygenates and Paraffin, Olefin, Naphthene, Aromatic
(O-PONA) Hydrocarbon Types in Low-Olefin Spark Ignition
Engine Fuels by Gas Chromatography
This standard is issued under the fixed designation D 6293; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope applied to other hydrocarbon streams having similar boiling
ranges, such as naphthas and reformates.
1.1 This test method provides for the quantitative determi-
1.6 The values stated in SI units are to be regarded as the
nation of oxygenates, paraffins, olefins, naphthenes, and aro-
standard.
matics in low-olefin spark-ignition engine fuels by multi-
1.7 This standard does not purport to address all of the
dimensional gas chromatography. Each hydrocarbon type can
safety concerns, if any, associated with its use. It is the
be reported either by carbon number (see Note 1) or as a total
responsibility of the user of this standard to establish appro-
through C , except for olefins, which can only be reported
priate safety and health practices and determine the applica-
through C . Higher boiling hydrocarbons cannot be reported by
bility of regulatory limitations prior to use.
type and are reported as a composite group. The lower limit of
detection for a single hydrocarbon component or carbon
2. Referenced Documents
number type is 0.05 mass %.
2.1 ASTM Standards:
NOTE 1—There can be an overlap between the C and C aromatics;
9 10
D 4307 Practice for Preparation of Liquid Blends for Use
however, the total is accurate. Isopropyl benzene is resolved from the C
As Analytical Standards
aromatics and is included with the other C aromatics. Naphthalene is
D 4815 Test Method for Determination of MTBE, ETBE,
determined with the C + components.
TAME, DIPE tert-Amyl Alcohol and C to C Alcohols in
1 4
1.2 This test method is applicable for total olefins in the 3
Gasoline by Gas Chromatography
range from 0.05 to 13 mass %. The test method can quantita-
D 5599 Test Method for Determination of Oxygenates in
tively determine olefins in samples where the olefin concen-
Gasoline by Gas Chromatography and Oxygen Selective
tration does not exceed 0.6 % C or 4.0 % C or 4.5 % of the 3
4 5
Flame Ionization Detection
combined C and C . Although the precision for benzene was
4 5
determined in the range from 0.3 to 1.0 mass %, this test
3. Terminology
method can be used to determine benzene concentrations up to
3.1 Definitions:
5.0 mass %.
3.1.1 oxygenate, n—an oxygen-containing organic com-
1.3 This test method is not intended to determine individual
pound, which may be used as a fuel or fuel supplement, for
hydrocarbon components except for those hydrocarbon types
example, various alcohols and ethers.
for which there is only one component within a carbon number.
3.2 Definitions of Terms Specific to This Standard:
Individually determined hydrocarbons are benzene, toluene,
3.2.1 hydrogenation, n—the process of adding hydrogen to
cyclopentane, propane, propylene, and cyclopentene.
olefin molecules as a result of a catalytic reaction.
1.4 Precision data has only been obtained on samples
3.2.1.1 Discussion—Hydrogenation is accomplished when
containing MTBE. Application of this test method to determine
olefins in the sample contact platinum at a temperature of
other oxygenates shall be verified in the user’s laboratory.
180°C in the presence of hydrogen. The olefins are converted
Methanol cannot be determined and shall be quantitated by an
into hydrogen saturated compounds of the same carbon number
appropriate oxygenate method such as Test Method D 4815 or
and structure. Monoolefins and diolefins convert to paraffins
D 5599. Methanol is fully resolved and does not interfere with
while cycloolefins and cyclodienes convert to cycloparaffins.
the determination of other components or groups.
3.2.2 trap, n—a device utilized to selectively retain specific
1.5 Although specifically written for spark-ignition engine
portions (individual or groups of hydrocarbons or oxygenates)
fuels containing oxygenates, this test method can also be
of the test sample and to release the retained components by
changing the trap temperature.
This test method is under the jurisdiction of ASTM Committee D-2 on
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.04.0L on Gas Chromatography. Annual Book of ASTM Standards, Vol 05.02.
Current edition approved Aug. 10, 1998. Published November 1998. Annual Book of ASTM Standards, Vol 05.03.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D6293–98
3.3 Acronyms: 5.2 The quantitative determination of olefins and other
3.3.1 ETBE, ethyl-tert-butylether.
hydrocarbon types in spark-ignition engine fuels is required to
3.3.2 MTBE, methyl-tert-butylether. comply with government regulations.
3.3.3 TAME, tert-amyl-methylether.
5.3 This test method is not applicable to M85 and E85 fuels,
which contain 85 % methanol and ethanol, respectively.
4. Summary of Test Method
4.1 A representative sample is introduced into a computer
6. Interferences
controlled gas chromatographic system consisting of switch-
ing valves, columns, and an olefin hydrogenation catalyst, all 6.1 Some types of sulfur-containing compounds are irre-
operating at various temperatures. The valves are actuated at versibly adsorbed in the olefin trap reducing its capacity to
pre-determined times to direct portions of the sample to retain olefins. Sulfur containing compounds are also adsorbed
appropriate columns and traps. As the analysis proceeds, the in the alcohol and ether-alcohol-aromatic (EAA) traps. How-
columns separate these sample portions sequentially into
ever, a variety of spark-ignition engine fuels have been
groups of different hydrocarbon types that elute to a flame
analyzed without significant performance deterioration of these
ionization detector.
traps.
4.2 The mass concentration of each detected compound or
6.2 Commercial dyes used to distinguish between grades
hydrocarbon group is determined by the application of re-
and types of spark-ignition engine fuels have not been found to
sponse factors to the areas of the detected peaks followed by
interfere with this test method.
normalization to 100 %. For samples containing methanol or
6.3 Commercial detergent additives utilized in spark-
other oxygenates that cannot be determined by this test
ignition engine fuels have not been found to interfere with this
method, the hydrocarbon results are normalized to 100 %
test method.
minus the value of the oxygenates as determined by another
6.4 Dissolved water in spark-ignition engine fuels has not
method such as Test Method D 4815 or D 5599. The liquid
been found to interfere with this test method.
volume concentration of each detected compound or hydrocar-
bon group is determined by application of density factors to the
7. Apparatus
calculated mass concentration of the detected peaks followed
by normalization to 100 %.
7.1 The complete system that was used to obtain the
precision data shown in Section 14 is comprised of a computer
5. Significance and Use
controlled gas chromatograph, automated sample injector, and
5.1 A knowledge of spark-ignition engine fuel composition
specific hardware modifications. These modifications include
is useful for regulatory compliance, process control, and
columns, traps, a hydrogenator, and valves, which are de-
quality assurance.
scribed below and in Section 8. Fig. 1 illustrates a typical
instrument configuration (see Note 8). Other configurations,
The sole source of supply of the apparatus known to the committee at this time,
components, or conditions may be utilized provided they are
the AC Reformulyzer, is AC Analytical Controls, Inc., 3494 Progress Dr., Bensalem,
capable of achieving the required component separations and
PA 19020. If you are aware of alternative suppliers, please provide this information
to ASTM Headquarters. Your comments will receive careful consideration at a
produce a precision that is equivalent, or better, than that
meeting of the responsible technical committee , which you may attend.
shown in the precision tables.
NOTE 1—Valve V4 and the Mol Sieve 5A Trap are not required but were present in the instrumentation used to generate the precision data.
FIG. 1 Typical Instrument Configuration
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D6293–98
7.2 Gas Chromatograph, capable of isothermal operation at indicated to accommodate specific systems. Temperature con-
specified temperatures, equipped with a heated flash vaporiza- trol may be by any means that will meet the requirements listed
tion inlet that can be packed (packed column inlet), a flame in Table 1.
ionization detector, necessary flow controllers, and computer
NOTE 3—The system components and temperatures listed in Table 1
control.
and Section 8 are specific to the analyzer used to obtain the precision data
7.3 Sample Introduction System, automatic liquid sampler,
shown in Section 14. Other columns and traps that can adequately perform
capable of injecting a 0.1 to 0.5-μL injection volume of liquid. the required separations are also satisfactory but may require different
temperatures.
The total injected sample shall be introduced to the chromato-
graphic system thus excluding the use of split injections or
7.7 Valves, Column and Trap Switching—Automated, rotary
carrier gas purging of the inlet septum. An auto injector is
valves are recommended. The valves shall be intended for gas
recommended but optional.
chromatographic usage and meet the following requirements:
7.4 Gas Flow and Pressure Controllers, with adequate
7.7.1 The valves must be capable of continuous operation at
precision to provide reproducible flow and pressure of helium
operating temperatures that will prevent sample condensation.
to the chromatographic system, hydrogen for the hydrogenator,
7.7.2 The valves shall be constructed of materials that are
and hydrogen and air for the flame ionization detector. Control
non-reactive with the sample under analysis conditions. Stain-
5 5
of air flow for cooling specific system components and for
less steel, PFA and Vespel are satisfactory.
automated valve operation is also required.
7.7.3 The valves shall have a small internal volume but offer
7.5 Electronic Data Acquisition System, shall meet or ex-
little restriction to carrier gas flow under analysis conditions.
ceed the following specifications (see Note 2):
7.8 Valves, air, to control pressurized air for column and
7.5.1 Capacity for 150 peaks for each analysis.
trap cooling. Automated valves are recommended.
7.5.2 Normalized area percent calculation with response
NOTE 4—New valves, tubing, catalyst, columns, traps, and other
factors.
materials that contact the sample or gasses may require conditioning prior
7.5.2.1 Area summation of peaks that are split or of groups
to operation in accordance with the manufacturer’s recommendations.
of components that elute at specific retention times.
7.9 Gas Purifiers, to remove moisture and oxygen from
7.5.3 Noise and spike rejection capability.
helium, moisture and hydrocarbons from hydrogen; and mois-
7.5.4 Sampling rate for fast (<0.5 s) peaks (>20 Hz to give
ture and hydrocarbons from air.
10 points across peak).
7.5.5 Peak width detection for narrow and broad peaks.
8. Reagents and Materials
7.5.6 Perpendicular drop and tangent skimming, as re-
8.1 Air, compressed,< 10 mg/kg each of total hydrocarbons
quired.
and H O( Warning—see Note 5).
NOTE 2—Standard supplied software is typically satisfactory.
NOTE 5—Warning: Compressed gas under high pressure that supports
7.6 Temperature Controllers of System Components—The
combustion.
independent temperature control of numerous columns and
8.2 Helium, 99.999 % pure, <0.1 mg/kg H O(Warning—
traps, the hydrogenation catalyst, column switching valves, and
see Note 6).
sample lines is required. All of the system components that
contact the sample shall be heated to a temperature that will
NOTE 6—Warning: Compressed gas under high pressure.
prevent condensation of any sample component. Table 1 lists
8.3 Hydrogen, 99.999 % pure, <0.1 mg/kg H O
the system components and operating temperatures (see Note
(Warning—see Note 7).
3). Some of the components require isothermal operation, some
NOTE 7—Warning: Extremely flammable gas under high pressure.
require rapid heating and cooling, while one requires repro-
ducible temperature programming. The indicated temperatures
8.4 Columns, Traps, and Hydrogenation Catalyst (System
are typical; however, the control systems utilized shall have the
Components)—This test method requires the use of four
capability of operating at temperatures 6 20°C of those
columns, two traps, and a hydrogenation catalyst (see Note 3).
Each system component is independently temperature con-
trolled as described in 7.6 and Table 1. Refer to Fig. 1 for the
TABLE 1 Temperature Control Ranges of System Components
location of the components in the system (see Note 8). The
Typical Operating Maximum Maximum
following list of components contains guidelines that are to be
Temperature Heating Time, Cooling Time,
Component Range, °C min min
used to judge suitability.
Alcohol trap 60 to 280 2 5
NOTE 8—Fig. 1 shows an additional trap, Molsieve 5A, and rotary
Polar column 130 isothermal
valve V4 that are not required for the O-PONA analysis. They are included
Non-polar column 130 isothermal
in Fig. 1 because they were present in the instrumentation used to generate
Olefin trap 120 to 280 1 5
Molsieve 13X column 90 to 430 temperature
the precision data. They can be used for more detailed analyses outside the
programmed, ;10°/min.
scope of this test method, where an iso-normal paraffin, iso- normal olefin
Porapak column 130 to 140 isothermal
determination is desired. There is no statistical data included in this test
Ether-alcohol-aromatic 70 to 280 1 5
method relating to their use.
(EAA) trap
Hydrogenation catalyst 180 isothermal
Column switching valves 130 isothermal
Sample lines 130 isothermal
PFA and Vespel are trademarks of E. I. DuPont de Nemours and Co.
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