ASTM D7041-04
(Test Method)Standard Test Method for Determination of Total Sulfur in Light Hydrocarbons, Motor Fuels, and Oils by Online Gas Chromatography with Flame Photometric Detection
Standard Test Method for Determination of Total Sulfur in Light Hydrocarbons, Motor Fuels, and Oils by Online Gas Chromatography with Flame Photometric Detection
SIGNIFICANCE AND USE
This test method can be used to determine total sulfur levels in process feeds and finished products that fall within the scope of this test method.
Low levels of sulfur in process feed stocks can poison expensive catalysts used in petroleum refining processes. This test method can be used to monitor sulfur levels in these feedstocks.
SCOPE
1.1 This test method covers the determination of total sulfur in liquid hydrocarbons with a final boiling point less than 450°C by gas chromatography using a flame photometric detector.
1.2 This test method is applicable for total sulfur levels from 0.5 to 100 mg S/kg.
Note 1—The pooled limit of quantification (PLOQ) derived from the 2002 interlaboratory cooperative test program was determined to be 1 mgS/kg.
Note 2—Samples can also be tested at other total sulfur levels, but the precision statements may not apply.
1.3 The values stated in SI units are to be regarded as standard.
1.4 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. For specific hazard statements see Section 7.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:D7041–04
Standard Test Method for
Determination of Total Sulfur in Light Hydrocarbons, Motor
Fuels, and Oils by Online Gas Chromatography with Flame
Photometric Detection
This standard is issued under the fixed designation D7041; 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 E840 Practice for Using Flame Photometric Detectors in
Gas Chromatography
1.1 This test method covers the determination of total sulfur
in liquid hydrocarbons with a final boiling point less than
3. Summary of Test Method
450°C by gas chromatography using a flame photometric
3.1 The sample is analyzed by gas chromatography with a
detector.
flame photometric detector. A fixed amount of sample is
1.2 Thistestmethodisapplicablefortotalsulfurlevelsfrom
injected into the gas chromatograph where it is vaporized. The
0.5 to 100 mg S/kg.
air carrier stream carries the vaporized sample into a high
NOTE 1—The pooled limit of quantification (PLOQ) derived from the
temperature zone (>900°C) where the compounds present in
2002 interlaboratory cooperative test program was determined to be 1
the sample are oxidized. Sulfur compounds are converted to
mgS/kg.
sulfur dioxide (SO ). The carrier stream carries the oxidation
NOTE 2—Samples can also be tested at other total sulfur levels, but the
components onto a chromatographic column where they are
precision statements may not apply.
separated and the SO is quantified by the flame photometric
1.3 The values stated in SI units are to be regarded as
detector.Calibrationofthedetectorisachievedbytheuseofan
standard.
appropriate external standard.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Significance and Use
responsibility of the user of this standard to establish appro-
4.1 This test method can be used to determine total sulfur
priate safety and health practices and determine the applica-
levelsinprocessfeedsandfinishedproductsthatfallwithinthe
bility of regulatory limitations prior to use. For specific hazard
scope of this test method.
statements see Section 7.
4.2 Low levels of sulfur in process feed stocks can poison
expensive catalysts used in petroleum refining processes. This
2. Referenced Documents
test method can be used to monitor sulfur levels in these
2.1 ASTM Standards:
feedstocks.
D1298 Test Method for Density, Relative Density (Specific
Gravity), or API Gravity of Crude Petroleum and Liquid
5. Apparatus
Petroleum Products by Hydrometer Method
5.1 Gas Chromatograph, equipped with automatically con-
D4052 Test Method for Density, Relative Density, and API
trolled valves, capable of automatic calibration with an exter-
Gravity of Liquids by Digital Density Meter
nal standard and having a flame photometric detector with an
D4057 Practice for Manual Sampling of Petroleum and
overall sensitivity to detect at least 0.5 mg/kg of SO . It must
Petroleum Products
be able to automatically control all valve switching times.
D4177 Practice for Automatic Sampling of Petroleum and
Although originally developed with online analytical measure-
Petroleum Products
mentequipmentinanofflinemodeofoperation,suitableonline
or laboratory gas chromatographs may apply this test method
This test method is under the jurisdiction of ASTM Committee D02 on
as described. Typical instrument parameters are listed in Table
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
1.
D02.03 on Elemental Analysis.
5.1.1 Carrier and Detector Gas Control—The chromato-
Current edition approved July 1, 2004. Published July 2004. DOI: 10.1520/
graph must be equipped with flow controllers or pressure
D7041-04.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
controllers capable of maintaining a constant supply of carrier
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
gas and detector supply gases. Electronic pressure or flow
Standards volume information, refer to the standard’s Document Summary page on
control is highly recommended.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7041–04
TABLE 1 Typical Instrument Parameters
used, provided it is first ascertained that the reagent is of
Carrier gas Zero air sufficiently high purity to permit its use without lessening the
Carrier flow rate 30 mL/min
accuracy of the determination.
Hydrogen flow rate 60 mL/min
Detector Flame photometric detector
6.2 Carrier-Gas—Zero grade air is recommended.
Detector temperature 120°C
(Warning—Compressed air is a gas under high pressure that
Injector temperature 285°C
supports combustion.)
Furnace temperature 1000°C
Column 40 ft by ⁄8 in. stainless steel tubing,
6.3 Hydrogen—Chromatographic grade recommended,
12 % polyphenyl ether/1.5 % H PO
3 4
minimum purity 99.995 %. (Warning—Hydrogen is an ex-
on 40/60 Chromosorb T
Column temperature 115°C
tremely flammable gas under high pressure.)
6.4 Solvent (Reagent Grade)—the solvent chosen should be
capable of dissolving the sulfur-containing compound used to
5.1.2 Sample Injection System—Anautomaticsampleinjec-
prepare the standard. The solvent of choice should have a
tion device is required. The injector must allow the introduc-
density similar to the samples being analyzed and it should
tion of small sample sizes (0.1 to 1 µL). The sample must be
have sulfur concentrations less than the instrument detection
accurately and repeatably injected into the gas chromatograph.
limit. Mixed solvents such as an isooctane / toluene mixture
Rotary or stem type liquid injection valves or auto injectors are
can be used to reach the desired density. (Warning—Solvents
recommended. The valve or injector must be equipped with a
used as reagents such as toluene and isooctane are flammable
heated vaporizer section capable of being heated to at least
and may be harmful or fatal if ingested or inhaled.)
285°C.
5.2 Pyrolysis Furnace—Afurnace capable of maintaining a
6.5 Standards for Calibration and Peak Identification—
sufficient temperature (>900°C) to pyrolyze the entire sample
Standards are used for peak identification and retention time
and oxidize the sulfur compounds to SO .
2 determination. Also standards of known concentrations are
5.3 Quartz Combustion Tube—Quartz tube capable of with-
required for external standard calibration of the gas chromato-
standing temperatures up to 1200°C. The oxidation section
graph.
shall be large enough to ensure complete oxidation of the
6.5.1 Preparation of Stock Solution (mass/volume), 100 µg
sample.
S/mL (see Notes 3 and 4).Accurately weigh to the nearest 0.1
5.4 Column—A column that can provide complete separa-
mg, 0.0456 g of butyl sulfide into a suitable container such as
tion of SO from the CO quench and the other oxidized
2 2
a 100 mL volumetric flask. Dilute to volume with the selected
components such as H O.
solvent.Thisstocksolutioncanbefurtherdilutedtothedesired
5.5 Detector—Any flame photometric detector (FPD) can
sulfur concentration. Other sulfur containing compounds such
be used, provided it can detect a minimum peak height twice
as thiophene or thianaphthene can be substituted for n-butyl
that of the baseline noise fora1µL injection of a 0.5 mg S/kg
sulfide if desired. The concentration of the stock solution can
standard. Detector linearity shall be at least equal to or greater
be calculated as follows:
than 10 .The user is referred to Practice E840 for assistance in
optimizing the operation and performance of the FPD.
µg S/mL 5 ~M 3 32.06! 3 ~1 3 10 !~µg/g!/~100 mL 3 FW! (1)
5.6 Data Acquisition System—Use any integrator or com-
where:
puterized data acquisition system for peak area integration, as
M = exact mass of sulfur reference compound (g), and
well as for recording the chromatographic trace. The device
FW = formula weight of sulfur reference compound.
and software must have the following capabilities:
5.6.1 Identification of peak by retention time.
NOTE 3—Commercial standards can be used provided they are checked
5.6.2 Calculation and use of response factors.
for accuracy.
5.6.3 External standard calibration calculation.
NOTE 4—Stock solutions will have a shelf life of approximately 2 to 3
5.6.4 Graphic presentation of the chromatogram.
months and should be remixed accordingly.
5.7 Analytical Balance—Any balance capable of accurately
6.5.2 Preparation of Stock Solution: (mass/mass), 100 µg
weighing materials to the nearest 0.01 mg.
S/g (see Notes 3 and 4). Accurately weigh to the nearest 0.1
6. Reagents and Materials
mg, 0.0456 g of butyl sulfide into a suitable container.Add 100
g (accurately weighed to the nearest 0.1 g) of the selected
6.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that solvent.Thisstocksolutioncanbefurtherdilutedtothedesired
all reagents shall conform to the specifications of the Commit- sulfur concentration. Other sulfur containing compounds such
tee onAnalytical Reagents of theAmerican Chemical Society, as thiophene or thianaphthene can be substituted for butyl
whe
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