ASTM D6733-01(2006)
(Test Method)Standard Test Method for Determination of Individual Components in Spark Ignition Engine Fuels by 50-Metre Capillary High Resolution Gas Chromatography
Standard Test Method for Determination of Individual Components in Spark Ignition Engine Fuels by 50-Metre Capillary High Resolution Gas Chromatography
SIGNIFICANCE AND USE
Knowledge of the individual component composition (speciation) of gasoline fuels and blending stocks is useful for refinery quality control and product specification. Process control and product specification compliance for many individual hydrocarbons may be determined through the use of this test method.
SCOPE
1.1 This test method covers the determination of individual hydrocarbon components of spark-ignition engine fuels with boiling ranges up to 225°C. Other light liquid hydrocarbon mixtures typically encountered in petroleum refining operations, such as, blending stocks (naphthas, reformates, alkylates, and so forth) may also be analyzed; however, statistical data was obtained only with blended spark-ignition engine fuels. The tables in enumerate the components reported. Component concentrations are determined in the range from 0.10 to 15 mass %. The procedure may be applicable to higher and lower concentrations for the individual components; however, the user must verify the accuracy if the procedures are used for components with concentrations outside the specified ranges.
1.2 This test method is applicable also to spark-ignition engine fuel blends containing oxygenated components. However, in this case, the oxygenate content must be determined by Test Methods D 5599 or D 4815.
1.3 Benzene co-elutes with 1-methylcyclopentene. Benzene content must be determined by Test Method D 3606 or D 5580.
1.4 Toluene co-elutes with 2,3,3-trimethylpentane. Toluene content must be determined by Test Method D 3606 or D 5580.
1.5 Although a majority of the individual hydrocarbons present are determined, some co-elution of compounds is encountered. If this procedure is utilized to estimate bulk hydrocarbon group-type composition (PONA) the user of such data should be cautioned that error may be encountered due to co-elution and a lack of identification of all components present. Samples containing significant amounts of naphthenic (for example, virgin naphthas) constituents above n-octane may reflect significant errors in PONA type groupings. Based on the interlaboratory cooperative study, this procedure is applicable to samples having concentrations of olefins less than 20 mass %. However, significant interfering coelution with the olefins above C7 is possible, particularly if blending components or their higher boiling cuts such as those derived from fluid catalytic cracking (FCC) are analyzed, and the total olefin content may not be accurate. Many of the olefins in spark ignition fuels are at a concentration below 0.10 %; they are not reported by this test method and may bias the total olefin results low.
1.5.1 Total olefins in the samples may be obtained or confirmed, or both, by Test Method D 1319 (volume %) or other test methods, such as those based on multidimensional PONA type of instruments.
1.6 If water is or is suspected of being present, its concentration may be determined, if desired, by the use of Test Method D 1744. Other compounds containing sulfur, nitrogen, and so forth, may also be present, and may co-elute with the hydrocarbons. If determination of these specific compounds is required, it is recommended that test methods for these specific materials be used, such as Test Method D 5623 for sulfur compounds.
1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are provided 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.
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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:D6733–01 (Reapproved 2006)
Standard Test Method for
Determination of Individual Components in Spark Ignition
Engine Fuels by 50-Metre Capillary High Resolution Gas
Chromatography
This standard is issued under the fixed designation D6733; 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 olefins above C is possible, particularly if blending compo-
nents or their higher boiling cuts such as those derived from
1.1 This test method covers the determination of individual
fluid catalytic cracking (FCC) are analyzed, and the total olefin
hydrocarbon components of spark-ignition engine fuels with
content may not be accurate. Many of the olefins in spark
boiling ranges up to 225°C. Other light liquid hydrocarbon
ignition fuels are at a concentration below 0.10 %; they are not
mixtures typically encountered in petroleum refining opera-
reported by this test method and may bias the total olefin
tions,suchas,blendingstocks(naphthas,reformates,alkylates,
results low.
and so forth) may also be analyzed; however, statistical data
1.5.1 Total olefins in the samples may be obtained or
was obtained only with blended spark-ignition engine fuels.
confirmed, or both, by Test Method D1319 (volume %) or
The tables in Annex A1 enumerate the components reported.
other test methods, such as those based on multidimensional
Component concentrations are determined in the range from
PONA type of instruments.
0.10 to 15 mass %. The procedure may be applicable to higher
1.6 If water is or is suspected of being present, its concen-
and lower concentrations for the individual components; how-
tration may be determined, if desired, by the use of Test
ever, the user must verify the accuracy if the procedures are
Method D1744. Other compounds containing sulfur, nitrogen,
used for components with concentrations outside the specified
and so forth, may also be present, and may co-elute with the
ranges.
hydrocarbons. If determination of these specific compounds is
1.2 This test method is applicable also to spark-ignition
required, it is recommended that test methods for these specific
engine fuel blends containing oxygenated components. How-
materials be used, such as Test Method D5623 for sulfur
ever, in this case, the oxygenate content must be determined by
compounds.
Test Methods D5599 or D4815.
1.7 The values stated in SI units are to be regarded as the
1.3 Benzene co-elutes with 1-methylcyclopentene. Benzene
standard. The values given in parentheses are provided for
content must be determined by Test Method D3606 or D5580.
information only.
1.4 Toluene co-elutes with 2,3,3-trimethylpentane. Toluene
1.8 This standard does not purport to address all of the
content must be determined by Test Method D3606 or D5580.
safety concerns, if any, associated with its use. It is the
1.5 Although a majority of the individual hydrocarbons
responsibility of the user of this standard to establish appro-
present are determined, some co-elution of compounds is
priate safety and health practices and determine the applica-
encountered. If this procedure is utilized to estimate bulk
bility of regulatory limitations prior to use.
hydrocarbon group-type composition (PONA) the user of such
data should be cautioned that error may be encountered due to
2. Referenced Documents
co-elution and a lack of identification of all components
2.1 ASTM Standards:
present. Samples containing significant amounts of naphthenic
D1319 Test Method for Hydrocarbon Types in Liquid
(for example, virgin naphthas) constituents above n-octane
Petroleum Products by Fluorescent Indicator Adsorption
may reflect significant errors in PONA type groupings. Based
D1744 Test Method for Determination of Water in Liquid
on the interlaboratory cooperative study, this procedure is
Petroleum Products by Karl Fischer Reagent
applicabletosampleshavingconcentrationsofolefinslessthan
D3606 Test Method for Determination of Benzene and
20 mass %. However, significant interfering coelution with the
Toluene in Finished Motor and Aviation Gasoline by Gas
Chromatography
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.04.0L on Gas Chromatography Methods.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2006. Published January 2007. Originally
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2001. Last previous edition approved in 2001 as D6733 – 01. DOI:
Standards volume information, refer to the standard’s Document Summary page on
10.1520/D6733-01R06.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6733–01 (2006)
TABLE 1 Operating Conditions
D4057 Practice for Manual Sampling of Petroleum and
Petroleum Products Temperatures Method 1 Method 2
D4420 Test Method for Determination of Aromatics in
Column initial isotherm, °C 35 10
Initial hold time, min. 10 15
Finished Gasoline by Gas Chromatography
Rate 1, °C/min. 1.1 1.3
D4815 Test Method for Determination of MTBE, ETBE,
Final temperature 1, °C 114 70
TAME, DIPE, tertiary-Amyl Alcohol and C to C Alco-
Hold time 2, min. 0 0
1 4
Rate 2, °C/min 1.7 1.7
hols in Gasoline by Gas Chromatography
Final temperature 2, °C 250 250
D5580 Test Method for Determination of Benzene, Tolu-
Final hold time 2, min. 5 20
ene, Ethylbenzene, p/m-Xylene, o-Xylene, C and Heavier
Injector, °C 250 250
Detector, °C 280 280
Aromatics, and Total Aromatics in Finished Gasoline by
Carrier gas helium pressure, kPA (psi) 207 (30) 190 (27)
Gas Chromatography
Flow rate (initial isotherm), mL/min. 0.9 0.7
D5599 Test Method for Determination of Oxygenates in
Average linear velocity, cm/s 22 21.5
Injection
Gasoline by Gas Chromatography and Oxygen Selective
Sample size, µL 0.5 0.3
Flame Ionization Detection
Splitter vent–flow out, mL/min. 250 200
D5623 Test Method for Sulfur Compounds in Light Petro-
leum Liquids by Gas Chromatography and Sulfur Selec-
tive Detection
a split injector, a carrier gas pressure control, and a flame
E355 Practice for Gas Chromatography Terms and Rela-
ionization detector which are required.
tionships
6.2 Sample Introduction System—Manual or automatic liq-
uid syringe sample injection may be employed.
3. Terminology
6.3 Data Acquisition System—Any data system can be used
3.1 Definitions—This test method makes reference to many
with a requirement:
common gas chromatographic procedures, terms, and relation-
6.3.1 Sampling rate of 10 Hz or more with a storage of
ships. Detailed definitions can be found in Practice E355.
sampling data for later processing.
6.3.2 Capacity for at least 400 peaks/analysis.
4. Summary of Test Method
6.3.3 Identificationofindividualcomponentsfromretention
4.1 Representative samples of the petroleum liquid are
time; software can be used to automatically identify the peaks
introduced into a gas chromatograph equipped with an open
with the index system determined from Table A1.1 or Table
tubular (capillary) column coated with specified stationary
A1.2.
phase(s). Helium carrier gas transports the vaporized sample
6.4 Sampling—Two millilitres or more crimp-top vials and
through the column in which it is partitioned into individual
aluminum caps with polytetrafluoroethylene (PTFE)-lined
components, which are sensed with a flame ionization detector
septa are used to transfer the sample.
as they elute from the end of the column. The detector signal
6.5 Capillary Column—A 50 m fused silica capillary col-
is recorded digitally by way of an integrator or integrating
umn with an internal diameter of 0.2 mm, containing a 0.5 µm
computer. Each eluting component is identified by comparing
film thickness of bonded dimethylpolysiloxane phase is used.
its retention time to those established by analyzing reference
The features must be respected to reproduce the separation of
standards or samples under identical conditions. The concen-
the reference chromatogram. The column must meet the
tration of each component in mass % is determined by normal-
criteria of efficiency, resolution, and polarity defined in Section
ization of the peak areas after correction of selected compo-
10.
nents with detector response factors. The unknown
components are reported individually as well as a summary
7. Reagents and Materials
total.
7.1 Carrier Gas and Make-up, helium, 99.99 mol % pure.
(Warning—Compressed gas under high pressure.)
5. Significance and Use
7.2 Fuel Gas, hydrogen, hydrocarbon free, 99.99 mol %
5.1 Knowledge of the individual component composition
pure. (Warning—Compressed gas under high pressure. Ex-
(speciation) of gasoline fuels and blending stocks is useful for
tremely flammable.)
refinery quality control and product specification. Process
7.3 Oxidizing Gas, air, 99 mol %. (Warning—Compressed
control and product specification compliance for many indi-
gas under high pressure.)
vidualhydrocarbonsmaybedeterminedthroughtheuseofthis
7.4 n-Pentane, 99+ mol % pure. (Warning—Extremely
test method.
flammable. Harmful if inhaled.)
7.5 n-Hexane, 99+ % mol % pure. (Warning—Extremely
6. Apparatus
flammable. Harmful if inhaled.)
6.1 Instrumentation—A gas chromatograph capable of op-
7.6 n-Heptane, 99+ mol % pure. (Warning—Extremely
erating under the conditions outlined inTable 1, equipped with flammable. Harmful if inhaled.)
7.7 2-Methylheptane, 99+ mol % pure. (Warning—
Extremely flammable. Harmful if inhaled.)
7.8 4-Methylheptane, 99+ mol % pure. (Warning—
Withdrawn. The last approved version of this historical standard is referenced
on www.astm.org. Extremely flammable. Harmful if inhaled.)
D6733–01 (2006)
7.9 n-Octane, 99+ mol % pure. (Warning—Extremely
n 5 5.545~Rt/W ! (1)
0.5
flammable. Harmful if inhaled.)
where:
7.10 n-Dodecane, 99+ mol % pure. (Warning—Extremely
n = number of theoretical plates,
flammable. Harmful if inhaled.)
Rt = retention time of normal octane, and
7.11 Toluene, 99+ mol % pure. (Warning—Extremely
W = mid-height peak width of normal octane in the
0.5
flammable. Harmful if inhaled.)
same unit as retention time.
7.12 System Performance Mixture—Weighanequalamount
10.2.1.1 The number of theoretical plates must be greater
of n-pentane, n-heptane, n-octane, n-dodecane,
than 200 000.
2-methylheptane, 4-methylheptane, and toluene. Dilute this
10.2.2 Resolution—Resolution is determined between the
mixture in n-hexane to obtain a concentration of 2 mass % for
peaks of 2-methylheptane and 4-methylheptane using Eq 2:
each compound.
2~Rt – Rt !
~a! ~b!
8. Sampling R 5 (2)
1.699 W 1 W
~ !
0.5 a! 0.5 b!
~ ~
8.1 Container Sampling—Samples shall be taken as de-
where:
scribed in Practice D4057 for instructions on manual sampling
Rt = retention time of 4-methylheptane,
into open container.
(a)
Rt = retention time of 2-methylheptane,
(b)
8.2 The sample and a 2–mLvial must be cooled at 4°C. Part
W = mid-height peak width of 4-methylheptane in
0.5(a)
ofthesampleistransferredto the vial up to 80 %ofitsvolume,
the same unit as retention time, and
and aluminum cap with septum is crimped.
W = mid-height peak width of 2-methylheptane in
0.5(b)
the same unit as retention time.
9. Preparation of Apparatus
10.2.2.1 The resolution must be equal to 4or greater than
9.1 Installation—Install and condition column in accor-
1.20.
dance with the supplier’s instruction.
10.2.3 Polarity—Polarity is defined by the McReynolds
9.2 Operating Conditions—Two sets of operating condi-
constant of toluene, using Eq 3:
tions are proposed in Table 1, the first with an initial column
temperature above the ambient temperature, the second with a
Rn 5 Ki – Ki (3)
tol ana squalane
sub-ambient column temperature profile. Adjust the operating
where:
conditions of the gas chromatograph to conform to the first or
Ki = toluene Kovats index on Squalane at
squalane
second method.
35°C = 742.6, and
9.3 Carrier Gas Pressure—Setacorrectcarriergaspressure
Ki = toluene Kovats index on the analytical col-
ana
using the system performance mixture such that the retention
umn at 35°C.
time of n-Heptane, n-Octane and n-Dodecane are between the
10.2.3.1 Toluene Kovats index is calculated using Eq 4:
values given in Table 2.
log T8 – log T8
R~t! R~h!
10. System Performance Evaluation Ki 5 700 1 100 (4)
S D
ana
log T8 – log T8
R~o! R~h!
10.1 Evaluation of the column and linearity of the split
where:
injection are carried out with a system performance mixture
T8 = adjusted retention time for toluene,
R(t)
defined in 7.12 and with the column temperature conditions
T8 = adjusted retention time for n-heptane, and
R(h)
defined in the following table.
T8 = adjusted retention time for n-octane.
R(o)
Initial temperature 35°C
Hold time 50 min. 10.2.3.2 Adjusted retention time of a peak is determined by
Final temperature 220°C
subtracting the retention time of an unretained compound (air
Hold time 20 min.
or methane) from the retention time of the peak. The McRey-
Rate 3°C/min.
nolds constant must be less than 10.
10.2 Column Evaluation—To perform the required separa-
10.2.4 Base Line Stability—Base line stability is calculated
tion, the column must meet three criteria of separation:
with the difference between area slices at the beginning and at
efficiency, resolution, and polarity.
the end of analysis, divided by the maximum area slice of
10.2.1 Effıciency—The number of theoretical plates is cal-
N-octane obtained with the system performance mixture.
culated with the normal octane peak using Eq 1:
10.2.4.1 Measurement of the Stability—Carry out one tem-
perature programming defined in 10.1 without injecting any
TABLE 2 Reference Retention Times of Normal Paraffins
sample. Subtract the area slices at the start of the analysis with
those corresponding to 120 min (average of three slices).
NOTE—Minutes and tenths of a minute.
10.2.4.2 Stability Standardization—Standardization is car-
Method 1 Method 1 Method 1 Method 2 Method 2 Method 2
ried out using the system performance mixture defined in 7.12
n-Paraffins Lower Reference Upper Lower Reference Upper
Time Time Time Time Time Time with the column temperature conditions defined in 10.1. The
n-Heptane 18.5 19.4 20.3 39.5 40.7 42.0
value obtained in 10.2.4.1 is divided by the maximum area
n-Octane 32.0 33.0 34.0 57.0 57.8 59.0
slice of N-octane and multiplied by 100. The value obtained
n-Dodecane 92.8 94.0 95.2 106.4 107.6 108.8
must be less than 2 %. If this is not the case, check for possible
...
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