ASTM D7041-16(2021)
(Test Method)Standard Test Method for Determination of Total Sulfur in Liquid Hydrocarbons and Hydrocarbon-Oxygenate Blends by Gas Chromatography with Flame Photometric Detection
Standard Test Method for Determination of Total Sulfur in Liquid Hydrocarbons and Hydrocarbon-Oxygenate Blends by Gas Chromatography with Flame Photometric Detection
SIGNIFICANCE AND USE
4.1 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.
4.2 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 mg/kg S to 100 mg/kg S.
Note 1: The pooled limit of quantification (PLOQ) derived from the 2002 interlaboratory cooperative test program was determined to be 1 mg/kg S.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements see Section 7.
1.5 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.
General Information
Relations
Standards Content (Sample)
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: D7041 − 16 (Reapproved 2021)
Standard Test Method for
Determination of Total Sulfur in Liquid Hydrocarbons and
Hydrocarbon-Oxygenate Blends by 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 ucts by Hydrometer Method
D4052 Test Method for Density, Relative Density, and API
1.1 This test method covers the determination of total sulfur
Gravity of Liquids by Digital Density Meter
in liquid hydrocarbons with a final boiling point less than
D4057 Practice for Manual Sampling of Petroleum and
450 °C by gas chromatography using a flame photometric
Petroleum Products
detector.
D4177 Practice for Automatic Sampling of Petroleum and
1.2 Thistestmethodisapplicablefortotalsulfurlevelsfrom
Petroleum Products
0.5 mg⁄kg S to 100 mg⁄kg S.
E840 PracticeforUsingFlamePhotometricDetectorsinGas
NOTE 1—The pooled limit of quantification (PLOQ) derived from the
Chromatography
2002 interlaboratory cooperative test program was determined to be
1 mg⁄kg S.
3. Summary of Test Method
NOTE 2—Samples can also be tested at other total sulfur levels, but the
precision statements may not apply.
3.1 The sample is analyzed by gas chromatography with a
1.3 The values stated in SI units are to be regarded as
flame photometric detector. A fixed amount of sample is
standard.
injected into the gas chromatograph where it is vaporized. The
air carrier stream carries the vaporized sample into a high
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the temperature zone (>900 °C) where the compounds present in
the sample are oxidized. Sulfur compounds are converted to
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- sulfur dioxide (SO ). The carrier stream carries the oxidation
components onto a chromatographic column where they are
mine the applicability of regulatory limitations prior to use.
separated and the SO is quantified by the flame photometric
For specific hazard statements see Section 7.
1.5 This international standard was developed in accor- detector.Calibrationofthedetectorisachievedbytheuseofan
appropriate external standard.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 4. Significance and Use
mendations issued by the World Trade Organization Technical
4.1 This test method can be used to determine total sulfur
Barriers to Trade (TBT) Committee.
levelsinprocessfeedsandfinishedproductsthatfallwithinthe
scope of this test method.
2. Referenced Documents
4.2 Low levels of sulfur in process feed stocks can poison
2.1 ASTM Standards:
expensive catalysts used in petroleum refining processes. This
D1298 Test Method for Density, Relative Density, or API
test method can be used to monitor sulfur levels in these
Gravity of Crude Petroleum and Liquid Petroleum Prod-
feedstocks.
5. Apparatus
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
5.1 Gas Chromatograph, equipped with automatically con-
Subcommittee D02.03 on Elemental Analysis.
trolled valves, capable of automatic calibration with an exter-
Current edition approved July 1, 2021. Published August 2021. Originally
nal standard and having a flame photometric detector with an
approved in 2004. Last previous edition approved in 2016 as D7041 – 16. DOI:
10.1520/D7041-16R21.
overall sensitivity to detect at least 0.5 mg/kg of SO . It must
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
be able to automatically control all valve switching times.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Although originally developed with online analytical measure-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. mentequipmentinanofflinemodeofoperation,suitableonline
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7041 − 16 (2021)
or laboratory gas chromatographs may apply this test method 6. Reagents and Materials
as described. Typical instrument parameters are listed in Table
6.1 Purity of Reagents—Reagent grade chemicals shall be
1.
used in all tests. Unless otherwise indicated, it is intended that
5.1.1 Carrier and Detector Gas Control—The chromato-
all reagents shall conform to the specifications of the Commit-
graph must be equipped with flow controllers or pressure
tee onAnalytical Reagents of theAmerican Chemical Society,
controllers capable of maintaining a constant supply of carrier
where such specifications are available. Other grades may be
gas and detector supply gases. Electronic pressure or flow
used, provided it is first ascertained that the reagent is of
control is highly recommended.
sufficiently high purity to permit its use without lessening the
5.1.2 Sample Injection System—An automatic sample injec-
accuracy of the determination.
tion device is required. The injector must allow the introduc-
6.2 Carrier-Gas—Zero grade air is recommended.
tionofsmallsamplesizes(0.1 µLto1 µL).Thesamplemustbe
(Warning—Compressed air is a gas under high pressure that
accurately and repeatably injected into the gas chromatograph.
supports combustion.)
Rotary or stem type liquid injection valves or auto injectors are
recommended. The valve or injector must be equipped with a 6.3 Hydrogen—Chromatographic grade recommended,
heated vaporizer section capable of being heated to at least minimum purity 99.995 %. (Warning—Hydrogen is an ex-
285 °C.
tremely flammable gas under high pressure.)
5.2 Pyrolysis Furnace—Afurnace capable of maintaining a 6.4 Solvent (Reagent Grade)—Thesolventchosenshouldbe
sufficient temperature (>900 °C) to pyrolyze the entire sample
capable of dissolving the sulfur-containing compound used to
and oxidize the sulfur compounds to SO . prepare the standard. The solvent of choice should have a
density similar to the samples being analyzed and it should
5.3 Quartz Combustion Tube—Quartz tube capable of with-
have sulfur concentrations less than the instrument detection
standing temperatures up to 1200 °C. The oxidation section
limit. Mixed solvents such as an isooctane / toluene mixture
shall be large enough to ensure complete oxidation of the
can be used to reach the desired density. (Warning—Solvents
sample.
used as reagents such as toluene and isooctane are flammable
5.4 Column—A column that can provide complete separa-
and may be harmful or fatal if ingested or inhaled.)
tion of SO from the CO quench and the other oxidized
2 2
6.5 Standards for Calibration and Peak Identification—
components such as H O.
Standards are used for peak identification and retention time
5.5 Detector—Any flame photometric detector (FPD) can
determination. Also standards of known concentrations are
be used, provided it can detect a minimum peak height twice
required for external standard calibration of the gas chromato-
that of the baseline noise for a 1 µL injection of a 0.5 mg⁄kg S
graph.
standard. Detector linearity shall be at least equal to or greater
6.5.1 Preparation of Stock Solution (mass/volume), 100 µg
than 10 .The user is referred to Practice E840 for assistance in
S/mL (see Notes 3 and 4). Accurately weigh to the nearest
optimizing the operation and performance of the FPD.
0.1 mg, 0.0456 g of butyl sulfide into a suitable container such
5.6 Data Acquisition System—Use any integrator or com- as a 100 mL volumetric flask. Dilute to volume with the
puterized data acquisition system for peak area integration, as selected solvent. This stock solution can be further diluted to
well as for recording the chromatographic trace. The device the desired sulfur concentration. Other sulfur containing com-
and software must have the following capabilities: pounds such as thiophene or thianaphthene can be substituted
5.6.1 Identification of peak by retention time. for n-butyl sulfide if desired. The concentration of the stock
5.6.2 Calculation and use of response factors. solution can be calculated as follows:
5.6.3 External standard calibration calculation.
µg S/mL 5 M 332.06 3 1 310 µg/g / 100 mL 3 FW (1)
~ ! ~ !~ ! ~ !
5.6.4 Graphic presentation of the chromatogram.
where:
5.7 Analytical Balance—Any balance capable of accurately
M = exact mass of sulfur reference compound (g), and
weighing materials to the nearest 0.01 mg.
FW = formula weight of sulfur reference compound.
NOTE 3—Commercial standards can be used provided they are checked
for accuracy.
NOTE 4—Stock solutions will have a shelf life of approximately 2 to 3
TABLE 1 Typical Instrument Parameters months and should be remixed accordingly.
Carrier gas Zero air
6.5.2 Preparation of Stock Solution: (mass/mass), 100 µg
Carrier flow rate 30 mL/min
S/g (see Notes 3 and 4). Accurately weigh to the nearest
Hydrogen flow rate 60 mL/min
0.1 mg, 0.0456 g of butyl sulfide into a suitable container.Add
Detector Flame photometric detector
Detector temperature 120 °C
100 g (accurately weighed to the nearest 0.1 g) of the selected
Injector temperature 285 °C
Furnace temperature 1000 °C
Column 40 ft by ⁄8 in. stainless steel
ACS Reagent Chemicals, Specifications and
...
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