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: D6839 − 18

Standard Test Method for

Hydrocarbon Types, Oxygenated Compounds, and Benzene
in Spark Ignition Engine Fuels by Gas Chromatography1
This standard is issued under the fixed designation D6839; 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* GC. The diluting solvent should not be considered in the

1.1 This test method covers the quantitative determination integration, this makes it possible to report the results of the
of saturates, olefins, aromatics, and oxygenates in spark- undiluted sample after normalization to 100 %.
ignition engine fuels by multidimensional gas chromatography. 1.4 Oxygenates as specified in Test Method D4815 have
Each hydrocarbon type can be reported either by carbon been verified not to interfere with hydrocarbons. Within the
number (see Note 1) or as a total. round robin sample set, the following oxygenates have been
NOTE 1—There can be an overlap between the C9 and C10 aromatics; tested: MTBE, ethanol, ETBE, TAME, iso-propanol,
however, the total is accurate. Isopropyl benzene is resolved from the C8 isobutanol, tert-butanol and methanol. The derived precision
aromatics and is included with the other C9 aromatics.
data for methanol do not comply with the precision calculation
1.2 This test method is not intended to determine individual as presented in this International Standard. Applicability of this
hydrocarbon components except benzene. test method has also been verified for the determination of
1.3 This test method is divided into two parts, Part A and n-propanol, acetone, and di-isopropyl ether (DIPE). However,
Part B. no precision data have been determined for these compounds.
1.3.1 Part A is applicable to automotive motor gasoline for 1.4.1 Other oxygenates can be determined and quantified
which precision (Table 9) has been obtained for total volume using Test Method D4815 or D5599.
fraction of aromatics of up to 50 %; a total volume fraction of 1.5 The method is harmonized with ISO 22854.
olefins from about 1.5 % up to 30 %; a volume fraction of
oxygenates, from 0.8 % up to 15 %; a total mass fraction of 1.6 This test method includes a relative bias section for U.S.
oxygen from about 1.5 % to about 3.7 %; and a volume fraction EPA spark-ignition engine fuel regulations for total olefins
of benzene of up to 2 %. Although this test method can be used reporting based on Practice D6708 accuracy assessment be-
to determine higher-olefin contents of up to 50 % volume tween Test Method D6839 and Test Method D1319 as a
fraction, the precision for olefins was tested only in the range possible Test Method D6839 alternative to Test Method
from about 1.5 % volume fraction to about 30 % volume D1319. The Practice D6708 derived correlation equation is
fraction. The method has also been tested for an ether content only applicable for fuels in the total olefins concentration range
up to 22 % volume fraction but no precision data has been from 0.2 % to 18.2 % by volume as measured by Test Method
determined. D6839. The applicable Test Method D1319 range for total
1.3.1.1 This test method is specifically developed for the olefins is from 0.6 % to 20.6 % by volume as reported by Test
analysis of automotive motor gasoline that contains Method D1319.
oxygenates, but it also applies to other hydrocarbon streams 1.7 The values stated in SI units are to be regarded as
having similar boiling ranges, such as naphthas and reformates. standard. No other units of measurement are included in this
1.3.2 Part B describes the procedure for the analysis of standard.
oxygenated groups (ethanol, methanol, ethers, C3 to C5 alco- 1.8 This standard does not purport to address all of the
hols) in ethanol fuels containing an ethanol volume fraction safety concerns, if any, associated with its use. It is the
between 50 % and 85 % (17 % to 29 % oxygen). The gasoline responsibility of the user of this standard to establish appro-
is diluted with an oxygenate-free component to lower the priate safety, health, and environmental practices and deter-
ethanol content to a value below 20 % before the analysis by mine the applicability of regulatory limitations prior to use.
1.9 This international standard was developed in accor-
1
This test method is under the jurisdiction of ASTM Committee D02 on dance with internationally recognized principles on standard-
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of ization established in the Decision on Principles for the
Subcommittee D02.04.0L on Gas Chromatography Methods.
Development of International Standards, Guides and Recom-
Current edition approved April 1, 2018. Published April 2018. Originally
approved in 2002. Last previous edition approved in 2017 as D6839 – 17. DOI: mendations issued by the World Trade Organization Technical
10.1520/D6839-18. Barriers to Trade (TBT) Committee.

*A Summary of Changes section appears at the end of this standard

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States

1
 D6839 − 18
2. Referenced Documents valves, columns, and an olefin hydrogenation catalyst, all
2.1 ASTM Standards: 2 operating at various temperatures. The valves are actuated at
D1319 Test Method for Hydrocarbon Types in Liquid Petro- predetermined times to direct portions of the sample to
leum Products by Fluorescent Indicator Adsorption appropriate columns and traps. As the analysis proceeds, the
D4307 Practice for Preparation of Liquid Blends for Use as columns separate these sample portions sequentially into
Analytical Standards groups of different hydrocarbon types that elute to a flame
D4815 Test Method for Determination of MTBE, ETBE, ionization detector.
TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alco- 4.2 The mass concentration of each detected compound or
hols in Gasoline by Gas Chromatography hydrocarbon group is determined by the application of re-
D5599 Test Method for Determination of Oxygenates in sponse factors to the areas of the detected peaks followed by
Gasoline by Gas Chromatography and Oxygen Selective normalization to 100 %. For samples containing methanol or
Flame Ionization Detection other oxygenates that cannot be determined by this test
D6708 Practice for Statistical Assessment and Improvement method, the hydrocarbon results are normalized to 100 %
of Expected Agreement Between Two Test Methods that minus the value of the oxygenates as determined by another
Purport to Measure the Same Property of a Material test method such as Test Method D4815 or D5599.
2.2 Other Documents: 4.3 The liquid volume concentration of each detected com-
ISO 4259 Petroleum products—Determination and applica- pound or hydrocarbon group is determined by application of
tion of precision data in relation to methods of test3 density factors to the calculated mass concentration of the
ISO 22854 Liquid petroleum products—Determination of detected peaks followed by normalization to 100 %.
hydrocarbon types and oxygenates in automotive-motor
gasoline—Multidimensional gas chromatography 5. Significance and Use
method3 5.1 A knowledge of spark-ignition engine fuel composition
3. Terminology is useful for regulatory compliance, process control, and
quality assurance.
3.1 Definitions:
3.1.1 oxygenate, n—an oxygen-containing organic 5.2 The quantitative determination of olefins and other
compound, which may be used as a fuel or fuel supplement, for hydrocarbon types in spark-ignition engine fuels is required to
example, various alcohols and ethers. comply with government regulations.
3.2 Definitions of Terms Specific to This Standard: 5.3 This test method is not applicable to M85 fuels, which
3.2.1 hydrogenation, n—the process of adding hydrogen to contain 85 % methanol.
olefin molecules as a result of a catalytic reaction.
6. Interferences
3.2.1.1 Discussion—Hydrogenation is accomplished when
olefins in the sample contact platinum at a temperature of 6.1 Some types of sulfur-containing compounds are irre-
180 °C in the presence of hydrogen. The olefins are converted versibly adsorbed in the olefin trap reducing its capacity to
into hydrogen saturated compounds of the same carbon number retain olefins. Sulfur containing compounds are also adsorbed
and structure. Monoolefins and diolefins convert to paraffins in the alcohol and ether-alcohol-aromatic (EAA) traps.
while cycloolefins and cyclodienes convert to cycloparaffins. However, a variety of spark-ignition engine fuels have been
analyzed without significant performance deterioration of these
3.2.2 trap, n—a device utilized to selectively retain specific
traps.
portions (individual or groups of hydrocarbons or oxygenates)
of the test sample and to release the retained components by 6.2 Commercial dyes used to distinguish between grades
changing the trap temperature. and types of spark-ignition engine fuels have been found not to
interfere with this test method.
3.3 Acronyms:
3.3.1 ETBE—ethyl-tert-butylether 6.3 Commercial detergent additives utilized in spark-
3.3.2 MTBE—methyl-tert-butylether ignition engine fuels have been found not to interfere with this
test method.
3.3.3 TAME—tert-amyl-methylether
6.4 Dissolved water in spark-ignition engine fuels has been
3.3.4 DIPE—di-isopropylether
found not to interfere with this test method.
4. Summary of Test Method
7. Apparatus
4.1 A representative sample is introduced into a computer
7.1 The complete system that was used to obtain the
controlled gas chromatographic system consisting of switching
precision data shown in Section 14 is comprised of a computer
controlled gas chromatograph, automated sample injector, and
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or specific hardware modifications. These modifications include
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM columns, traps, a hydrogenator, and valves, which are de-
Standards volume information, refer to the standard’s Document Summary page on
scribed in 7.7 and in Section 8. Fig. 1 illustrates a typical
the ASTM website.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., instrument configuration (see Note 4). Other configurations,
4th Floor, New York, NY 10036, http://www.ansi.org. components, or conditions may be utilized provided they are

2
 D6839 − 18

FIG. 1 Typical Instrument Configuration

capable of achieving the required component separations and 7.5.2 Normalized area percent calculation with response
produce a precision that is equivalent to, or better than, that factors.
shown in the precision tables. 7.5.2.1 Area summation of peaks that are split or of groups
7.2 Gas Chromatograph, capable of temperature pro- of components that elute at specific retention times.
grammed operation at specified temperatures, equipped with a 7.5.3 Noise and spike rejection capability.
heated flash vaporization inlet, a flame ionization detector, 7.5.4 Sampling rate for fast (<0.5 s) peaks (>20 Hz to give
necessary flow controllers, and computer control. 10 points across peak).
7.3 Sample Introduction System, using an automatic liquid 7.5.5 Peak width detection for narrow and broad peaks.
injector, the injection volume shall be chosen in a way such 7.5.6 Perpendicular drop and tangent skimming, as re-
that the capacity of the column is not exceeded and that the quired.
linearity of the detector is valid. NOTE 2—Standard supplied software is typically satisfactory.
7.3.1 An injection volume of 0.1 µL has been found
satisfactory. 7.6 Temperature Controllers of System Components—The
independent temperature control of numerous columns and
7.4 Gas Flow and Pressure Controllers, with adequate traps, the hydrogenation catalyst, column switching valves, and
precision to provide reproducible flow and pressure of the sample lines is required. All of the system components that
carrier gas to the chromatographic system, hydrogen for the contact the sample shall be heated to a temperature that will
hydrogenator, and hydrogen and air for the flame ionization prevent condensation of any sample component. Table 1 lists
detector. Control of air flow for cooling specific system the system components and operating temperatures (see 7.6.1).
components and for automated valve operation is also required. Some of the components require isothermal operation, some
7.5 Electronic Data Acquisition System, shall meet or ex- require rapid heating and cooling, while one requires repro-
ceed the following specifications (see Note 2): ducible temperature programming. The indicated temperatures
7.5.1 Capacity for 150 peaks for each analysis. are typical; however, the control systems utilized shall have the

3
 D6839 − 18
TABLE 1 Temperature Control Ranges of System Components 8.3 Hydrogen, 99.999 % pure, <0.1 mg/kg H2 O.
Typical
Maximum Maximum
(Warning—Extremely flammable gas under high pressure.)
Operating
Component Heating Cooling
Temperature
Time, min Time, min
8.4 Columns, Traps, and Hydrogenation Catalyst (System
Range, °C Components)—Suitable columns and traps for reversible ab-
Alcohol trap 60–280 2 5 sorption of certain selected chemical groups must be used (an
Polar column 130 isothermal
Non-polar column 130 isothermal example is given in Table 1, see also 7.6.1). Each system
Olefin trap 120–280 1 5 component is independently temperature controlled as de-
Molsieve 13X column 90–430 Temperature scribed in 7.6 and Table 1. Refer to Fig. 1 for the location of the
programmed, ~10°/min
Ether-alcohol-aromatic 70–280 1 5 components in the system (see Note 4). The following list of
(EAA) trap components contains guidelines that are to be used to judge
Hydrogenation catalyst 180 isothermal
Column switching valves 130 isothermal
suitability. The guidelines describe temperatures and times as
Sample lines 130 isothermal used in a typical system. Alternatives can be used provided that
the separation as described is obtained and the separation
characteristics of the entire system are not limited.
capability of operating at temperatures 620 °C of those indi- NOTE 4—Fig. 1 shows an additional trap, Molsieve 5A, and rotary valve
cated to accommodate specific systems. Temperature control V4 that are not required for this test method. They are included in Fig. 1
because they were present in the instrumentation used to generate the
may be by any means that will meet the requirements listed in precision data. They can be used for more detailed analyses outside the
Table 1. scope of this test method, where an iso-normal paraffin, iso-normal olefin
7.6.1 The system components and temperatures listed in determination is desired. There is no statistical data included in this test
Table 1 and Section 8 are specific to the analyzer used to obtain method relating to their use.
the precision data shown in Section 14. Other columns and 8.4.1 Alcohol Trap—Within a temperature range from
traps that can adequately perform the required separations are 140 °C to 160 °C, this trap must elute benzene, toluene, all
also satisfactory but may require different temperatures. paraffins, olefins, naphthenes, and ethers within the first 2 min
7.7 Valves, Column and Trap Switching—Suitable auto- after sample injection while retaining C8+ aromatics, all
mated switching valves are recommended. The valves shall be alcohols, and any other sample components.
intended for gas chromatographic usage and meet the follow- 8.4.1.1 At a temperature of 280 °C, all retained components
ing requirements: from 8.4.1 shall elute within 2 min of when the trap is
7.7.1 The valves must be capable of continuous operation at backflushed.
operating temperatures that will prevent sample condensation. 8.4.2 Polar Column—At a temperature of 130 °C, this
7.7.2 The valves shall be constructed of materials that are column must retain all aromatic components in the sample
nonreactive with the sample under analysis conditions. Stain- longer than the time required to elute all non-aromatic com-
less steel, PFA, and Vespel4 are satisfactory. ponents boiling below 185 °C, within the first 5 min after
7.7.3 The valves shall have a small internal volume but offer sample injection.
little restriction to carrier gas flow under analysis conditions. 8.4.2.1 The column shall elute benzene, toluene, and all
7.7.4 New valves, tubing, catalyst, columns, traps, and other non-aromatic components with a boiling point below 215 °C
materials that contact the sample or gasses may require within 10 min of the introduction of these compounds into the
conditioning prior to operation in accordance with the manu- column.
facturer’s recommendations.
8.4.2.2 This column shall elute all retained aromatic com-
7.8 Gas Purifiers, to remove moisture and oxygen from ponents from 8.4.2 within 10 min of when this column is
helium, moisture and hydrocarbons from hydrogen, and mois- backflushed.
ture and hydrocarbons from air. 8.4.3 Non-Polar Column—At a temperature of 130 °C, this
8. Reagents and Materials column shall elute and separate aromatics by carbon number
boiling below 200 °C. Higher boiling paraffins, naphthenes,
8.1 Air, compressed, <10 mg/kg each of total hydrocarbons and aromatics are backflushed.
and H2O. (Warning—Compressed gas under high pressure 8.4.4 Olefin Trap—Within a temperature range from 90 °C
that supports combustion.) to 105 °C, this trap shall retain (trap) all olefins in the sample
8.2 Carrier Gas, Helium or Nitrogen, 99.999 % pure, <0.1 for at least 6.5 min and elute all non-olefinic components up to
mg/kg H2O. (Warning—Compressed gas under high pres- C7 in less than 6.5 min after the sample is injected. Non-
sure.) olefinic components C9 and higher shall be retained during this
NOTE 3—The system’s operating parameters such as column & trap
time.
temperatures, carrier gas flows and valve switching times are depending 8.4.4.1 Within a temperature range from 140 °C to 150 °C
on the type of carrier gas used. The use of nitrogen as carrier gas may not this trap shall retain C6 and higher olefins and elute all
be possible on all configurations. Contact the equipment manufacturer for non-olefinic components in 3 min. Olefins up to C6 may or may
specific information or instructions on the use of nitrogen.
not elute in this time.
8.4.4.2 At a temperature of 280 °C, this trap shall quantita-
4
PFA and Vespel are trademarks of E. I. DuPont de Nemours and Co. tively elute all retained olefins.

4
 D6839 − 18
TABLE 2 System Validation Test Mixture
Approximate Approximate
Component Concentration Concentration Warning
Mass, % Volume, %
A
Cyclopentane 1.1 1.1
A
Pentane 1.1 1.4
A
Cyclohexane 2.1 2.1
A
2,3-Dimethylbutane 2.1 2.5
A
Hexane 2.1 2.5
A
1-Hexene 1.5 1.7
A
Methylcyclohexane 4.0 4.1
A
4-Methyl-1-hexene 1.6 1.8
B
Heptane 3.5 4.0
A
1- cis-2-Dimethylcyclohexane 5.0 5.0
B
2,2,4-Trimethylpentane 5.0 5.5
B
Octane 5.0 5.5
B
1- cis-2- cis-4-Trimethylcyclohexane 4.0 4.0
B
Nonane 4.5 4.9
B
Decane 4.5 4.8
B
Undecane 3.5 3.7
B
Dodecane 3.5 3.7
B
Benzene 2.2 1.9
B
Methylbenzene (Toluene) 2.2 2.0
B
trans-Decahydronaphthalene (Decalin) 4.0 3.5
B
Tetradecane 4.5 4.7
A
Ethylbenzene 4.5 4.0
A
1,2-Dimethylbenzene (o-Xylene) 4.0 3.6
A
Propylbenzene 5.0 4.5
A
1,2,4-Trimethylbenzene 4.5 4.0
A
1,2,3-Trimethylbenzene 5.0 4.5
B
1,2,4,5-Tetramethylbenzene 5.0 4.5
C
Pentamethylbenzene 5.0 4.5

Group Totals
Total Aromatics 37.4 33.5
Total Olefins 3.1 3.5
Total Saturates 59.5 63.0
Benzene 2.20 1.90
A
(Warning—Extremely flammable. Harmful if inhaled.)
B
(Warning—Flammable. Harmful if inhaled.)
C
(Warning—Harmful if inhaled.)

8.4.5 Molsieve 13X Column—This column shall separate 8.5 Test Mixture—A quantitative synthetic mixture of pure
paraffin and naphthene hydrocarbons by carbon number when hydrocarbons is required to verify that all instrument
temperature programmed from 90 °C to 430 °C at approxi- components, temperatures, and cut times are satisfactory to
mately 10 ° ⁄min. produce accurate analyses and to aid in making operating
8.4.6 Porapak Column—At a temperature from 130 °C to adjustments as columns and traps age. The mixture may be
140 °C, this column shall separate individual oxygenates, purchased or prepared according to Practice D4307. Each
benzene, and toluene. component used in the test mixture preparations shall have a
NOTE 5—The use of a Porapak column is not required in all configu-
minimum purity of 99 %. The actual concentration levels are
rations. For more information on a specific system, contact the equipment not critical but shall be accurately known.
manufacturer. 8.5.1 System Validation Test Mixture, used to monitor and
8.4.7 Ether-Alcohol-Aromatic (EAA) Trap—Within a tem- make adjustments to the total operation of the system. The
perature range from 105 °C to 130 °C, this trap shall retain all composition and approximate component concentrations are
of the ethers in the sample and elute all non-aromatic hydro- shown in Table 2.
carbons boiling below 175 °C within the first 6 min after 8.6 Quality Control Sample, used to routinely monitor the
sample injection. operation of the chromatographic system and verify that
8.4.7.1 At a temperature of 280 °C, this trap shall elute all reported concentrations are within the precision of the test
retained components. method. Depending on the range and composition of the
8.4.8 Hydrogenation Catalyst, platinum. At a temperature of samples to be analyzed, more than one quality control sample
180 °C and an auxiliary hydrogen flow of 14 mL ⁄min 6 2 may be necessary. Any sample that is similar in composition to
mL/min, this catalyst shall quantitatively hydrogenate all samples typically analyzed may be designated as the quality
olefins to paraffinic compounds of the same structure without control (QC) sample. The QC sample shall be of sufficient
cracking. volume to provide an ample supply for the intended period of

5
 D6839 − 18
TABLE 3 Typical Gas Flow Rates 10. Standardization
Gas Flow Rate 10.1 The elution of components from the columns and traps
He (Flow A) 22 ± 2 mL/min depends on the applied temperatures. The switching valves
He (Flow B) 12 ± 1 mL/min
H2 (hydrogenator) 14 ± 2 mL/min also need to be actuated at exact times to make separations of
H2 (FID) 30–35 mL/min compounds into groups, for example, to retain specific com-
Air (FID) 400–450 mL/min pounds in a column or trap while permitting other compounds
to elute. Therefore, the separation temperatures of the columns/
traps and the valve timing are critical for correct operation of
the system. These parameters need to be verified on the start up
use and it shall be homogeneous and stable under the antici- of a new system (see Note 6) for correctness. They also require
pated storage conditions. evaluation and adjustment as necessary on a regular basis to
8.6.1 The quality control sample should have similar com- correct for changes to columns and traps as a result of aging. To
position and hydrocarbon distribution as the sample with do this, the analyst shall analyze several test mixtures and
highest olefin concentration routinely analyzed. make changes, as required, based on an evaluation of the
8.6.2 The quality control sample should contain oxygenates resulting chromatograms and test reports.
as analyzed in routine samples. Separate standards could be 10.2 Using the procedure outlined in Section 11, analyze the
used for different oxygenates. system validation test mixture. Carefully examine the chro-
8.6.2.1 In the event that samples containing TAME or matogram obtained to verify that all the individual components
ethanol need to be analyzed, it is best to use separate standards of the test mixture are correctly identified as compared to the
since optimal separation of these components requires different reference chromatogram (Figs. 2 and 3). Test results for groups
alcohol trap temperature conditions. by hydrocarbon number and group totals shall agree with the
8.7 Diluting solvent, used in Part B, should not be interfer- known composition (see Table 2) within the 95 % confidence
ing with any other component in gasoline being analyzed. level or reproducibility of the group/component divided by the
Dodecane (C12H26) or tridecane (C13H28) are recommended square root of 2. Table 4 presents the calculated level for
solvents. selected components or groups. If these specifications are met,
proceed to the analysis of the quality control samples (see
9. Preparation of Apparatus 10.3).
10.2.1 If the specifications in 10.2 are not met, adjust the
9.1 Assemble the analyzer system (gas chromatograph with
temperature of specific columns and traps or valve timing
independent temperature controlled components) as shown in
according to the manufacturer’s guidelines and reanalyze the
Fig. 1 or with a similar flow system. If using a commercial
system validation test mixture until they are met.
system, install and place the system in service in accordance
with the manufacturer’s instructions. 10.3 Analyze quality control samples; see 8.6. Verify that
results are consistent with those previously obtained and that
9.2 Impurities in the carrier gas, hydrogen, or air will have
the separation of olefins and saturates is correct.
a detrimental effect on the performance of the columns and
10.3.1 Breakthrough of olefins to the saturate fraction is
traps. Therefore, it is important to install efficient gas purifiers
indicated by a rising baseline under the C5 to C6 saturates
in the gas lines as close to the system as possible and to use
region or additional peaks between the C4 and C6 peaks. If
good quality gases. The carrier gas and hydrogen gas connec-
breakthrough is observed, optimize the olefin trap temperature
tion lines shall be made of metal. Check that all gas
or, if necessary, replace the trap.
connections, both exterior and interior to the system, are leak
10.3.2 If the fraction containing C4 to C6 olefins and C7 to
tight.
C10 saturates shows peaks in the C7 region, optimize the olefin
9.3 The gas flow rates on commercial instruments are trap temperatures or, if necessary, replace the trap.
normally set prior to shipment and normally require little 10.3.3 Loadability limits for olefins are listed in 1.3. These
adjustment. Optimize flow rates on other systems to achieve limits depend on the condition of the olefin trap, and an aged
the required separations. Typical flow rates for the commercial trap may not have this capacity. Use the quality control sample
instrument used in the precision study are given in Table 3; (see 8.6) to verify olefin capacity.
however, the flows can differ somewhat from system to system. 10.3.4 Check that the correct qualitative and quantitative
9.3.1 Set air flow rates for column/trap cooling and for analysis of oxygenates are achieved for the quality control
operation of air actuated valves, if required. sample. If qualitative or quantitative specifications are not met,
9.4 System Conditioning—When gas connections have been optimize the alcohol trap temperature and ether-alcohol-
disconnected or the flow turned off, as on initial start up, aromatic trap temperature or replace the columns as necessary.
condition the system by permitting carrier gas to flow through 10.4 Reanalyze the system validation test mixture whenever
the system for at least 30 min while the system is at ambient the quality control sample does not conform to expected results
temperature. After the system has been conditioned, analyze (see 10.3) and make adjustments as necessary (see 10.2).
the system validation test mixture, as described in Section 11,
discarding the results.

6
 D6839 − 18

FIG. 2 Example of a Gravimetric Test Blend Analysis 1/2

FIG. 3 Example of a Gravimetric Test Blend Analysis 2/2

Part A—PROCEDURE APPLICABLE TO AUTOMOTIVE MOTOR GASOLINE AND HYDROCARBON STREAMS

WITH SIMILAR BOILING RANGES

7
 D6839 − 18

FIG. 4 Typical Gasoline Chromatogram 1/2

FIG. 5 Typical Gasoline Chromatogram 2/2

TABLE 4 Calculated Acceptance Levels for Validation Sample

Component Group Concentration Level Acceptance Level
Volume %
Aromatics 33.5 ±1.1
Olefins 3.5 ±0.9
Saturates 63.0 ±1.1
Benzene 1.9 ±0.11

11. Procedure

11.1 Load the necessary system setpoint conditions, which NOTE 6—Commercial systems will have all parameters predetermined
include initial component temperatures, times at which column and accessible through the software. Other constructed systems will
and trap temperature are changed, the initial positions of require experimentation and optimization of parameters to achieve the
required component separation and precision.
switching valves, and times when valve switches occur (see
Note 6).

8
 D6839 − 18
TABLE 5 Calculated Response Factors for HydrocarbonsA ,B
TABLE 6 Experimentally Determined Response Factors for
Oxygenates
NOTE 1—Use a factor of 0.883 for polynaphthenes.
Compound Response Factor
No. of Mono-
Naph- Cyclo- Ethanol 1.870
Carbon Paraffins Olefins and Aromatics
thenes Olefins tert-Butanol 1.229
Atoms Diolefins
MTBE 1.334
3 0.916 0.916
ETBE 1.242
4 0.906 0.906
TAME 1.242
5 0.874 0.899 0.874 0.899
DIPE 1.317
6 0.874 0.895 0.874 0.895 0.811
Methanol 3.80
7 0.874 0.892 0.874 0.892 0.820
n-Propanol 1.867
8 0.874 0.890 0.874 0.890 0.827
iso-Propanol 1.742
9 0.874 0.888 0.874 0.888 0.832
n-Butanol 1.546
10 0.874 0.887 0.874 0.887 0.837
iso-Butanol 1.390
11+ 0.887 0.840
sec-Butanol 1.390
A
Based on percentage by mass of carbon, normalized to methane = 1.
B
Corrected for hydrogenation of olefins.

where:
11.2 When all component temperatures have stabilized at RRf = relative response factor for a hydrocarbon type
the analysis conditions, inject a representative aliquot of group of a particular carbon number,
sample (or test mixture) and start the analysis. Typically, 0.1 µL Caw = atomic mass of carbon, 12.011,
has been found to be suitable. Cn = number of carbon atoms in the hydrocarbon type
11.2.1 Starting the analysis should begin the data acquisi- group, of a particular carbon number,
tion and should begin the timing function that controls all of Haw = atomic mass of hydrogen, 1.008,
the various programmed temperature changes and valve Hn = number of hydrogen atoms in the hydrocarbon type
switching. group of a particular carbon number, and
11.2.2 Upon completion of its programmed cycle, the sys- 0.7487 = factor to normalize the result to a methane re-
tem should automatically stop, generate a chromatogram, and sponse of unity, (1).
print a report of concentrations. 12.1.1.2 Oxygenate flame ionization detector response fac-
tors used in the precision study were determined experimen-
12. Calculation
tally and are listed in Table 6.
12.1 Calculations produce results that are reported in 12.1.2 Calculate the liquid volume % of each identified
mass % and liquid volume %. Examine the report carefully to hydrocarbon group and oxygenate using Eq 3.
ensure that all peaks have been properly identified and inte-
M
grated.
D
12.1.1 Calculate the mass % of each identified hydrocarbon V5 (3)
M
group of a particular carbon number and individual oxygenate ( D
using Eq 1.
A 3 F 3 100 where:
M5 (1) V = liquid volume % of an identified hydrocarbon group of
( A 3F a particular carbon number or individual oxygenate,
where: M = previously defined, Eq 1, and
M = mass % of an identified hydrocarbon group of a D = average relative density, kg/L at 20 °C, (see Note 7) for
particular carbon number or individual oxygenate, the hydrocarbon group of a particular carbon number or
A = integrated area of the hydrocarbon group of a particu- individual oxygenate. For hydrocarbons, use Table 7 and for
lar carbon number or individual oxygenate, oxygenates, use Table 8.
F = relative response factor for the hydrocarbon group, NOTE 7—Relative density of 15.5 °C can also be used but Tables 7 and
RRf, calculated using Eq 2 or from Table 5. For 8 will not apply.
oxygenates, use the response factors from Table 6, or 12.1.3 Calculate the oxygen content, wO, from all identified
factors determined on the specific system (see oxygenate compounds, i, according to Eq 4:
12.1.1.2), and
100 = factor to normalize corrected area % to 100 %.
12.1.1.1 Calculate the flame ionization detector response
wO 5 Σ
i
S nO 3 MO
Mi
3 wi D (4)

factor relative to methane, which is considered to have a where:

response factor of unity (1), for each hydrocarbon group type nO = the number of oxygen atoms in the molecule, gener-
of a particular carbon number using Eq 2. Olefin response is ally 1,
calculated on a hydrogenated basis. MO = atomic mass of oxygen,
@ ~ C aw 3 C n ! 1 ~ H aw 3 H n ! # 3 0.7487 Mi = molecular mass of the oxygenated compound, and
RRf 5 (2) wi = percent mass fraction of the compound in the mixture.
~ C aw 3 C n !

9
 D6839 − 18
TABLE 7 Average Relative Density, kg/L at 20 °C, of Hydrocarbon TABLE 9 Reporting of Components
Type GroupsA Hydrocarbon Group
Report, Mass % and LV %
NOTE 1—Use an average relative density of 0.8832 for the polynaph- Type and Oxygenates
thenes. Saturates Total, one decimal precision
Olefins Total, one decimal precision
No. of Mono-
Naph- Cyclo- Aromatics Total, one decimal precision
Carbon Paraffins Olefins and Aromatics
thenes Olefins Oxygenates By Component, two decimals precision
Atoms Diolefins
Benzene Two decimals precision
3 0.5005 0.5139 Total Oxygen Two decimals precision
4 0.5788 0.6037
5 0.7454 0.6262 0.7720 0.6474
6 0.7636 0.6594 0.7803 0.6794 0.8789
7 0.7649 0.6837 0.7854 0.7023 0.8670
8 0.7747 0.7025 0.8000 0.7229 0.8681 13.1.3 Calculate the total for the aromatics by summation of
9 0.7853 0.7176 0.8073 0.7327 0.8707
10 0.8103 0.7300 0.8724
the C6 to C10 aromatics and the C11+ aromatics.
11+ 0.740 0.874
A
ASTM publication DS 4A, Physical Constants of Hydrocarbons. C11+ groups
14. Precision and Bias5
utilize an average of data available from the Handbook of Chemistry and Physics, 14.1 Precision—The precision of any individual measure-
69th Ed., 1988-1989. Available from ASTM International.
ment resulting from the application of this test method depends
on several factors related to the individual or group of
TABLE 8 Relative Density, kg/L at 20 °C, of OxygenatesA components including the volatility, concentration, and degree
Oxygenate Relative Density
to which the component or group of components is resolved
Ethanol 0.7967
from closely eluting components or groups of components. As
tert-Butanol 0.7910 it is not practical to determine the precision of measurement for
MTBE 0.7459 every component or group of components at different levels of
ETBE 0.7440
TAME 0.7710 concentration separated by this test method, Tables 10 and 11
DIPE 0.7240 present the repeatability and reproducibility values for
Methanol 0.7965 selected, representative components, and groups of compo-
n-Propanol 0.7925
iso-Propanol 0.7925 nents.
n-Butanol 0.8147 14.1.1 Repeatability—The difference between successive
iso-Butanol 0.8052 results obtained by the same operator with the same apparatus
sec-Butanol 0.8144
A
under constant operating conditions on identical test materials
ASTM publication DS 4B, Physical Constants of Hydrocarbons, available from
ASTM International.
would, in the long run, in the normal and correct operation of
the test method, exceed the repeatability values shown in
Tables 10 and 11 only in one case in twenty.
14.1.2 Reproducibility—The difference between two single
and independent results obtained by different operators work-
12.1.3.1 Example—This example calculation uses MTBE ing in different laboratories on identical test materials would, in
(C5H12O) as the only oxygenate compound and the following the long run, in the correct operation of the test method, exceed
atomic masses: the values shown in Tables 10 and 11 only in one case in
—C 12.011 twenty.
—H 1.008 NOTE 8—Although the precision for benzene was determined in the
—O 16.000 range from 0.5 % to 1.6 % by mass, this test method can be used to

wO 5 Σ S nO 3 MO
Mi
3 wi D determine a mass fraction benzene concentration up to 5.0 %.
14.2 Bias—No information can be presented on the bias of
1 3 16.000 the procedure in Test Method D6839 for measuring hydrocar-
5 3 wi bon types because no material having an accepted reference
5 3 12.011112 3 1.00811 3 16.000
5 0.1815 3 w i (5)
value is available.
14.3 Relative Bias—A relative bias assessment of Test
13. Report Method D6839 versus Test Method D1319 for the determina-
13.1 Report the mass percent and liquid volume percent for tion of total olefins in spark-ignition engine fuel was conducted
each hydrocarbon group type to the nearest 0.1 % as listed in using data from the ASTM D02 Interlaboratory Crosscheck
Table 9 and report the mass percent and liquid volume percent Program. The assessment was performed in accordance with
for individual carbon number components, each oxygenate, the requirements of Practice D6708 with a successful outcome.
and the total oxygen mass percent to the nearest 0.01 %. It was based on measurements of total olefins in spark ignition
13.1.1 Calculate the total for the saturates by summation of fuels supplied between December 2010 and October 2014 by
the C5 to C10 naphthenes, the C3 to C10 paraffins, the the Reformulated Gasoline program of the ASTM Proficiency
poly-naphthenes and the C11+ saturates.
13.1.2 Calculate the total for the olefins by summation of 5
Supporting data have been filed at ASTM International Headquarters and may
the C5 to C10 cyclic olefins and the C3 to C10 mono and be obtained by requesting Research Report RR:D02-1544. Contact ASTM Customer
diolefins. Service at service@astm.org.

10
 D6839 − 18
TABLE 10 Repeatability and Reproducibility for Selected NOTE 9—In the United States, the EPA requires the measurement of
Oxygenate and Hydrocarbon Type Components and Groups of total olefins in spark-ignition engine fuels by Test Method D1319.
Components Effective Jan. 1, 2016, there is an allowance in the regulation to use other
test methods if they are formally correlated with the specified test method
NOTE 1—The reporting unit for the covered range is in liquid volume
percent except for the level of oxygen, which is in weight percent. by a consensus organization, for example, ASTM. This relative bias
statement is intended to satisfy the requirement and allow use of Test
Component or Covered Method D6839 bias-corrected results in the stated concentration ranges in
Repeatability Reproducibility
Group Range
place of Test Method D1319 for total olefins.
Aromatics 0.012 (10 + X) 0.036· (10 + X) 20–45 v/v
Olefins 0.13 · X 0.46 0.72 · X 0.46 0–28 v/v 14.3.1 The degree of agreement between results from Test
Saturates 0.5 1.6 25–80 v/v
Oxygen 0.02 0.10 0.25–1.8 Method D6839 and Test Method D1319 can be further im-
m/m proved by applying a correlation equation (Eq 6) (Research
1.6 1.6
Benzene 0.019 · X 0.053 · X 0.5–1.6 v/v
Report RR:D02-1818),6 and this correlation equation shall be
MTBE 0.14 0.37 10 v/v
Ethanol 0.06 0.37 0.5–4 v/v utilized when reporting compliance with EPA fuels program.
ETBE 0.09 0.67 10 v/v There were no discernable sample-specific biases as defined in
TAME 0.07 0.71 4.5 v/v
iso-Propanol 0.19 1.35 10 v/v Practice D6708.
iso-Butanol 0.24 0.65 10.1 v/v 14.3.2 The correlation equation is:
tert-Butanol 0.13 0.48 6.7 v/v
Predicted Test Method D1319 = C D6839 (6)

where:
TABLE 11 Calculated Repeatability and Reproducibility at Various
Concentration Levels Predicted Test Method D1319 = Test Method D1319 pre-
Component Concentration dicted volume percent, and
Repeatability Reproducibility
Group Level (vol/vol)
Aromatics 20 0.4 1.1 CD6839 = Test Method D6839 re-
25 0.4 1.3 ported volume percent.
30 0.5 1.4
35 0.5 1.6 14.3.2.1 The correlation equation is only applicable for
40 0.6 1.8
45 0.7 2.0 fuels in the stated concentration range from 0.2 % to 18.2 % by
volume as reported by Test Method D6839.
Olefins 1 0.1 0.7
3 0.2 1.2 14.3.2.2 The correlation equation is applicable for fuels that
5 0.3 1.5 when determined by Test Method D1319 are in the concentra-
10 0.4 2.1
15 0.5 2.5 tion range of 0.6 % to 20.6 % by volume.
18 0.5 2.7
20 0.5 2.9 NOTE 10—The Test Method D1319 concentration range used to develop
25 0.6 3.2 the Practice D6708 assessment may not cover the entire scope of Test
30 0.6 3.4 Method D1319 for total olefins.
Benzene 0.5 0.01 0.02
NOTE 11—The correlation equation was developed from a variety of
1.0 0.02 0.05 fuel samples from the ASTM Interlaboratory Crosscheck programs;
1.5 0.04 0.10 however, it is recommended that the correlation equation be verified for
2.0 0.06 0.16 samples of interest to ensure applicability.

Testing Program (Interlaboratory Crosscheck Program) and is

documented in Research Report RR:D02-1818.6

6
Supporting data have been filed at ASTM International Headquarters and may
be obtained by requesting Research Report RR:D02-1818. Contact ASTM Customer
Service at service@astm.org.

PART B—PROCEDURE APPLICABLE TO SAMPLES CONTAINING ETHANOL IN THE RANGE OF 50 % TO

85 % BY VOLUME
15. Procedure

15.1 Introduction—The procedure as described in this sec- I trap (see Table 1) cannot trap high amounts of ethanol, the
tion can be used to analyze gasoline samples containing higher sample must be diluted. A typical chromatogram is given in
amounts of ethanol such as E85 with ethanol percentages in the Fig. 6.
range between 50 % and 85 % (V/V). As the sulphate column

11
 D6839 − 18

FIG. 6 Typical Chromatogram of an E85 Fuel

15.2 Select a dilutant (8.7) that does not interfere with the 17. Report
analysis, dodecane (C12H26) or tridecane (C13H28) have proven 17.1 Report the mass percent and liquid volume percent for
to be adequate. each oxygenate and hydrocarbon group type to the nearest 0.1
15.3 The dilution factor should be chosen in such way that % as listed in Table 9 and report the mass percent and liquid
the final amount of ethanol does not exceed 20 % (V/V). volume percent for individual carbon number components to
the nearest 0.01 %.
15.4 Load the necessary system set point conditions, which
include initial component temperatures, times at which column 17.1.1 Calculate the total for the saturates by summation of
and trap temperature are changed, the initial positions of the C5 to C10 naphthenes, the C3 to C10 paraffins, the
switching valves, and times when valve switches occur (see polynaphthenes and the C11+ saturates.
Note 12). 17.1.2 Calculate the total for the olefins by summation of
the C5 to C10 cyclic olefins and the C3 to C10 mono and
NOTE 12—Commercial systems will have all parameters predetermined diolefins.
and accessible through the software. Other constructed systems will 17.1.3 Calculate the total for the aromatics by summation of
require experimentation and optimization of parameters to achieve the
required component separation and precision. the C6 to C10 aromatics and the C11+ aromatics.
15.5 When all component temperatures have stabilized at 18. Precision and Bias
the analysis conditions, inject a representative aliquot of
sample (or test mixture) and start the analysis. Typically 0.1 µL 18.1 A full round robin was organized by CEN and ISO in
has been found to be suitable. which 14 labs participated. The sample set consisted of ten
15.5.1 Starting the analysis should begin the data acquisi- sample blends of ethanol and gasoline in the range of 50 % to
tion and should begin the timing function that controls all of 85 % (V/V) ethanol. The blends were prepared by using two
the various programmed temperature changes and valve different ethanol and two different oxygenate-free gasoline
switching. samples. Precision was established using the ISO 4259 calcu-
lations. The ether range tested was between 0.25 % and 1.6 %
15.5.2 Upon completion of its programmed cycle, the sys-
(V/V), the higher alcohols were tested is a range of 1.4 % to 2.5
tem should automatically stop, generate a chromatogram, and
% (V/V).
print a report of concentrations.
18.2 Precision—The precision of any individual measure-
16. Calculation ment resulting from the application of this test method depends
on several factors related to the individual or group of
16.1 The peak area of the dilutant should not be integrated
components including the volatility, concentration, and degree
so that the final report, after normalization to 100 %, will give
to which the component or group of components is resolved
the results for the relevant groups and components for the
from closely eluting components or groups of components. As
undiluted sample.
it is not practical to determine the precision of measurement for
16.2 Follow the calculation procedure as described in Sec- every component or group of components at different levels of
tion 12. concentration separated by this test method, Table 12 presents

12
 D6839 − 18
TABLE 12 Repeatability and Reproducibility Related to High
Ethanol Gasoline Samples
Component or Group Repeatability Reproducibility
r R
% volume % volume fractionA
fractionA
Ethanol (>50 % and <85 %) 1.24 4.85
Ethers (>0.5 % and <1.6 %) 0.03 0.33
C3–C5 alcohols (>1.4 % and <2.5 %) 0.1032 X + 0.0011 0.6963 X + 0.0731
A
X is the mean of the two results being compared in % (V/V) unless otherwise
stated.

the repeatability and reproducibility values for selected, repre- 18.3 Bias—No information can be presented on the bias of
sentative components, and groups of components. the procedure in Test Method D6839 for measuring hydrocar-
18.2.1 Repeatability—The difference between successive bon types because no material having an accepted reference
results obtained by the same operator with the same apparatus value is available.
under constant operating conditions on identical test materials
would, in the long run, in the normal and correct operation of 19. Keywords
the test method, exceed the repeatability values shown in Table
12 only in one case in twenty. 19.1 aromatics; gas chromatography; gasoline; hydrocarbon
18.2.2 Reproducibility—The difference between two single type; multidimensional gas chromatography; naphthenes; ole-
and independent results obtained by different operators work- fins; oxygenates; saturates; spark-ignition engine fuels
ing in different laboratories on identical test materials would, in
the long run, in the correct operation of the test method, exceed
the values shown in Table 12 only in one case in twenty.

SUMMARY OF CHANGES

Subcommittee D02.04 has identified the location of selected changes to this standard since the last issue
(D6839 – 17) that may impact the use of this standard. (Approved April 1, 2018.)

(1) Revised 13.1.

Subcommittee D02.04 has identified the location of selected changes to this standard since the last issue
(D6839 – 16) that may impact the use of this standard. (Approved June 1, 2017.)

(1) Revised Table 2. (3) Added new Table 4.

(2) Revised subsection 10.2.

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13