ASTM D7039-15a(2020)
(Test Method)Standard Test Method for Sulfur in Gasoline, Diesel Fuel, Jet Fuel, Kerosine, Biodiesel, Biodiesel Blends, and Gasoline-Ethanol Blends by Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry
Standard Test Method for Sulfur in Gasoline, Diesel Fuel, Jet Fuel, Kerosine, Biodiesel, Biodiesel Blends, and Gasoline-Ethanol Blends by Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry
SIGNIFICANCE AND USE
4.1 This test method provides for the precise measurement of the total sulfur content of samples within the scope of this test method with minimal sample preparation and analyst involvement. The typical time for each analysis is five minutes.
4.2 Knowledge of the sulfur content of diesel fuels, gasolines, and refinery process streams used to blend gasolines is important for process control as well as the prediction and control of operational problems such as unit corrosion and catalyst poisoning, and in the blending of products to commodity specifications.
4.3 Various federal, state, and local agencies regulate the sulfur content of some petroleum products, including gasoline and diesel fuel. Unbiased and precise determination of sulfur in these products is critical to compliance with regulatory standards.
SCOPE
1.1 This test method covers the determination of total sulfur by monochromatic wavelength-dispersive X-ray fluorescence (MWDXRF) spectrometry in single-phase gasoline, diesel fuel, refinery process streams used to blend gasoline and diesel, jet fuel, kerosine, biodiesel, biodiesel blends, and gasoline-ethanol blends.
Note 1: Volatile samples such as high-vapor-pressure gasolines or light hydrocarbons might not meet the stated precision because of the evaporation of light components during the analysis.
1.2 The range of this test method is between the pooled limit of quantitation (PLOQ) value (calculated by procedures consistent with Practice D6259) of 3.2 mg/kg total sulfur and the highest level sample in the round robin, 2822 mg/kg total sulfur.
1.3 Samples containing oxygenates can be analyzed with this test method provided the matrix of the calibration standards is either matched to the sample matrices or the matrix correction described in Section 5 or Annex A1 is applied to the results. The conditions for matrix matching and matrix correction are provided in the Interferences section (Section 5).
1.4 Samples with sulfur content above 2822 mg/kg can be analyzed after dilution with appropriate solvent (see 5.4). The precision and bias of sulfur determinations on diluted samples has not been determined and may not be the same as shown for neat samples (Section 15).
1.5 When the elemental composition of the samples differ significantly from the calibration standards used to prepare the calibration curve, the cautions and recommendation in Section 5 should be carefully observed.
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard information, see 3.1.
1.8 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.
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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: D7039 − 15a (Reapproved 2020)
Standard Test Method for
Sulfur in Gasoline, Diesel Fuel, Jet Fuel, Kerosine,
Biodiesel, Biodiesel Blends, and Gasoline-Ethanol Blends
by Monochromatic Wavelength Dispersive X-ray
Fluorescence Spectrometry
This standard is issued under the fixed designation D7039; 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 1.6 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
1.1 This test method covers the determination of total sulfur
only.
by monochromatic wavelength-dispersive X-ray fluorescence
1.7 This standard does not purport to address all of the
(MWDXRF)spectrometryinsingle-phasegasoline,dieselfuel,
safety concerns, if any, associated with its use. It is the
refinery process streams used to blend gasoline and diesel, jet
responsibility of the user of this standard to establish appro-
fuel,kerosine,biodiesel,biodieselblends,andgasoline-ethanol
priate safety, health, and environmental practices and deter-
blends.
mine the applicability of regulatory limitations prior to use.
NOTE 1—Volatile samples such as high-vapor-pressure gasolines or
For specific hazard information, see 3.1.
light hydrocarbons might not meet the stated precision because of the
1.8 This international standard was developed in accor-
evaporation of light components during the analysis.
dance with internationally recognized principles on standard-
1.2 Therangeofthistestmethodisbetweenthepooledlimit ization established in the Decision on Principles for the
of quantitation (PLOQ) value (calculated by procedures con- Development of International Standards, Guides and Recom-
sistent with Practice D6259) of 3.2 mg⁄kg total sulfur and the mendations issued by the World Trade Organization Technical
highest level sample in the round robin, 2822 mg⁄kg total Barriers to Trade (TBT) Committee.
sulfur.
2. Referenced Documents
1.3 Samples containing oxygenates can be analyzed with
2.1 ASTM Standards:
this test method provided the matrix of the calibration stan-
D4057 Practice for Manual Sampling of Petroleum and
dards is either matched to the sample matrices or the matrix
Petroleum Products
correction described in Section 5 or AnnexA1 is applied to the
D4177 Practice for Automatic Sampling of Petroleum and
results. The conditions for matrix matching and matrix correc-
Petroleum Products
tion are provided in the Interferences section (Section 5).
D6259 Practice for Determination of a Pooled Limit of
1.4 Samples with sulfur content above 2822 mg⁄kg can be
Quantitation for a Test Method
analyzed after dilution with appropriate solvent (see 5.4). The
D6299 Practice for Applying Statistical Quality Assurance
precision and bias of sulfur determinations on diluted samples
and Control Charting Techniques to Evaluate Analytical
has not been determined and may not be the same as shown for
Measurement System Performance
neat samples (Section 15).
D6300 Practice for Determination of Precision and Bias
Data for Use in Test Methods for Petroleum Products,
1.5 When the elemental composition of the samples differ
Liquid Fuels, and Lubricants
significantly from the calibration standards used to prepare the
D7343 Practice for Optimization, Sample Handling,
calibration curve, the cautions and recommendation in Section
Calibration, and Validation of X-ray Fluorescence Spec-
5 should be carefully observed.
trometry Methods for Elemental Analysis of Petroleum
Products and Lubricants
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.03 on Elemental Analysis. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2020. Published June 2020. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2004. Last previous edition approved in 2015 as D7039 – 15a. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7039-15AR20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7039 − 15a (2020)
FIG. 1 Schematic of the MWDXRF Analyzer
2.2 EPA Documents: catalyst poisoning, and in the blending of products to com-
40 CFR 80.584 Code of Federal Regulations; Title 40; Part modity specifications.
80; U.S. Environmental Agency, July 1, 2005
4.3 Various federal, state, and local agencies regulate the
sulfur content of some petroleum products, including gasoline
3. Summary of Test Method
anddieselfuel.Unbiasedandprecisedeterminationofsulfurin
3.1 A monochromatic X-ray beam with a wavelength suit-
these products is critical to compliance with regulatory stan-
able to excite the K-shell electrons of sulfur is focused onto a
dards.
test specimen contained in a sample cell (see Fig. 1). The
fluorescent Kα radiation at 0.5373 nm (5.373 Å) emitted by
5. Interferences
sulfur is collected by a fixed monochromator (analyzer). The
5.1 Differences between the elemental composition of test
intensity (counts per second) of the sulfur X rays is measured
samplesandthecalibrationstandardscanresultinbiasedsulfur
using a suitable detector and converted to the concentration of
determinations. For samples within the scope of this test
sulfur (mg/kg) in a test specimen using a calibration equation.
method, elements contributing to bias resulting from differ-
Excitation by monochromatic X rays reduces background,
ences in the matrices of calibrants and test samples are
simplifies matrix correction, and increases the signal/
hydrogen, carbon, and oxygen. A matrix-correction factor (C)
backgroundratiocomparedtopolychromaticexcitationusedin
can be used to correct this bias; the calculation is described in
conventional WDXRF techniques. (Warning—Exposure to
AnnexA1. For general analytical purposes, the matrices of test
excessive quantities of X-ray radiation is injurious to health.
samples and the calibrants are considered to be matched when
The operator needs to take appropriate actions to avoid
the calculated correction factor C is within 0.98 to 1.04. No
exposing any part of his/her body, not only to primary X rays,
matrix correction is required within this range. A matrix
but also to secondary or scattered radiation that might be
correction is required when the value of C is outside the range
present. The X-ray spectrometer should be operated in accor-
of 0.98 to 1.04. For most testing, matrix correction can be
dance with the regulations governing the use of ionizing
avoided with a proper choice of calibrants. For example, based
radiation.)
on the example graph in Annex A1 (Fig. 2), a calibrant with
86 % by mass carbon and 14 % by mass hydrogen can cover
4. Significance and Use
non-oxygen containing samples with C/H ratios from 5.4 to
4.1 This test method provides for the precise measurement
8.5. For gasolines with oxygenates, up to 2.3 % by mass
of the total sulfur content of samples within the scope of this
oxygen (12 % by mass MTBE) can be tolerated for test
test method with minimal sample preparation and analyst
samples with the same C/H ratio as the calibrants.
involvement.Thetypicaltimeforeachanalysisisfiveminutes.
5.2 Fuels containing large quantities of oxygenates, such as
4.2 Knowledge of the sulfur content of diesel fuels,
biodiesel, biodiesel blends, and gasoline-ethanol blends, can
gasolines, and refinery process streams used to blend gasolines
have a high oxygen content leading to significant absorption of
is important for process control as well as the prediction and
sulfur Kα radiation and low sulfur results.
control of operational problems such as unit corrosion and
5.2.1 Biodiesel and biodiesel blends may be analyzed using
this test method by applying correction factors to the results or
using calibration standards that are matrix-matched to the test
Available from U.S. Government Printing Office, 732 N. Capitol Street, NW,
sample(seeTable1).Correctionfactorsmaybecalculated(see
Washington, DC 20401.
Annex A1), or obtained from Table 2 if the sample has been
Bertin, E. P., Principles and Practices of X-ray Spectrometric Analysis, Plenum
Press, New York, 1975, pp. 115–118. measured on a mineral oil calibration curve.
D7039 − 15a (2020)
FIG. 2 Matrix Correction for a Test Sample vs. C/H and Total Oxygen Content Using Chromium Kα for the Excitation Beam
TABLE 1 Methods for Interference Correction by Sample Type
5.4.1 A base material for gasoline can be approximately
Correction simulated by mixing 2,2,4-trimethylpentane (isooctane) and
Tables (Table Correction
toluene in a ratio that approximates the expected aromatic
Matrix
Sample Type 2, Table 3, Calculation
Matching
content of the samples to be analyzed.
Table 4,or (Annex A1)
N/A)
Biodiesel and Biodiesel Blends 2 Yes Yes
6. Apparatus
Gasoline-ethanol Blends 3 or 4 Yes Yes
All Other Sample Types N/A Yes Yes 6.1 Monochromatic Wavelength Dispersive X-ray Fluores-
cence (MWDXRF) Spectrometer , equipped for X-ray detec-
tion at 0.5373 nm (5.373Å).Any spectrometer of this type can
be used if it includes the following features, and the precision
and bias of test results are in accordance with the values
5.2.2 Gasoline-ethanol blends may be analyzed using this
described in Section 15.
test method by applying correction factors to the results or
6.1.1 X-ray Source, capable of producing X rays to excite
using calibration standards that are matrix matched to the test
sulfur. X-ray tubes with a power >25W capable of producing
sample(seeTable1).Correctionfactorsmaybecalculated(see
Rh Lα,PdLα,AgLα,TiKα,ScKα, and Cr Kα radiation are
Annex A1), or obtained from the correction tables. Use Table
recommended for this purpose.
3 if the sample has been measured on a mineral oil calibration
6.1.2 Incident-beam Monochromator, capable of focusing
curve, or use Table 4 if the sample has been measured on an
and selecting a single wavelength of characteristic X rays from
ethanol calibration curve. Ethanol-based calibrants can be used
the source onto the specimen.
for gasoline-ethanol blends. Ethanol-based calibrants are rec-
6.1.3 Optical Path, designed to minimize the absorption
ommended for gasoline-ethanol blends containing more than
along the path of the excitation and fluorescent beams using a
50 % (by volume) ethanol.
vacuum or a helium atmosphere. A vacuum of < 2.7 kPa
5.3 Other samples having interferences as described in 5.1
(<20 Torr) is recommended. The calibration and test measure-
may be analyzed using this test method by applying correction
ments must be done with identical optical paths, including
factors to the results or by using calibration standards that are
vacuum or helium pressure.
matrix matched to the test sample (see Table 1). Correction
6.1.4 Fixed-channel Monochromator,suitablefordispersing
factors may be calculated as described in Annex A1.
sulfur Kα X rays.
5.4 To minimize any bias in the results, use calibration
standards prepared from sulfur-free base materials of the same
The sole source of this apparatus known to the committee at this time is X-ray
or similar elemental composition as the test samples. When
Optical Systems, Inc., 15 Tech Valley Drive, East Greenbush, NY12061. If you are
diluting samples, use a diluent with an elemental composition
aware of alternative suppliers, please provide this information to ASTM Interna-
the same or similar to the base material used for preparing the
tional Headquarters.Your comments will receive careful consideration at a meeting
calibration standards. of the responsible technical committee, which you may attend.
D7039 − 15a (2020)
TABLE 2 Correction Factors for Biodiesel Blends Measured on a Mineral Oil Calibration Curve
NOTE 1—Determine the correction factor in the table below by finding the known oxygen content of the test specimen (for example, 11 wt %) as the
sum of the value in the first column and the value in the first row (for example, 11 = 10+1). The intersection of these two values is the correction factor
(for example, 1.1914). Apply the correction according to 12.5.
Oxygen, wt % 0 % 1 % 2 % 3 % 4 % 5 % 6 % 7 % 8 % 9 %
0 % 1.0000 1.0174 1.0348 1.0522 1.0696 1.0870 1.1044 1.1218 1.1392 1.1566
10 % 1.1740 1.1914 1.2088 1.2262 1.2436 1.2610 1.2784 1.2958 1.3132 1.3306
TABLE 3 Correction Factors for Gasoline-ethanol Blends Measured on a Mineral Oil Calibration Curve
NOTE 1—Determine the correction factor in the table below by finding the known ethanol content of the test specimen (for example, 15 vol %) as the
sum of the value in the first column and the value in the first row (for example, 15 = 10+5). The intersection of these two values is the correction factor
(for example, 1.0881). Apply the correction according to 12.5.
Ethanol, vol % 0 % 1 % 2 % 3 % 4 % 5 % 6 % 7 % 8 % 9 %
0 % 0.9895 0.9962 1.0029 1.0095 1.0161 1.0228 1.0294 1.0360 1.0425 1.0491
10 % 1.0556 1.0621 1.0686 1.0751 1.0816 1.0881 1.0945 1.1009 1.1073 1.1137
20 % 1.1201 1.1265 1.1328 1.1391 1.1455 1.1518 1.1580 1.1643 1.1706 1.1768
30 % 1.1830 1.1892 1.1954 1.2016 1.2077 1.2139 1.2200 1.2261 1.2322 1.2383
40 % 1.2444 1.2504 1.2565 1.2625 1.2685 1.2745 1.2805 1.2865 1.2924 1.2984
50 % 1.3043 1.3102 1.3161 1.3220 1.3279 1.3337 1.3396 1.3454 1.3512 1.3570
60 % 1.3628 1.3686 1.3743 1.3801 1.3858 1.3915 1.3972 1.4029 1.4086 1.4143
70 % 1.4199 1.4256 1.4312 1.4368 1.4424 1.4480 1.4536 1.4591 1.4647 1.4702
80 % 1.4757 1.4813 1.4868 1.4922 1.4977 1.5032 1.5086 1.5141 1.5195 1.5249
90 % 1.5303 1.5357 1.5410 1.5464 1.5518 1.5571 1.5624 1.5677 1.5730 1.5783
TABLE 4 Correction Factors for Gasoline-ethanol Blends Measured on an Ethanol Calibration Curve
NOTE 1—Determine the correction factor in the table below by finding the known ethanol content of the test specimen (for example, 85 vol %) as the
sum of the value in the first column and the value in the first row (for example, 85 = 80+5). The intersection of these two values is the correction factor
(for example, 0.9492). Apply the correction according to 12.5. Refer to 7.8 and 10.1 for ethanol calibration.
Ethanol, vol % 0 % 1 % 2 % 3 % 4 % 5 % 6 % 7 % 8 % 9 %
0 % 0.6248 0.6291 0.6333 0.6375 0.6417 0.6459 0.6500 0
...
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