ASTM D7757-22
(Test Method)Standard Test Method for Silicon in Gasoline and Related Products by Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry
Standard Test Method for Silicon in Gasoline and Related Products by Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry
SIGNIFICANCE AND USE
5.1 This test method provides rapid and precise measurement of total silicon in naphthas, gasoline, gasoline-ethanol blends, RFG, ethanol and ethanol-fuel blends, and toluene with minimum sample preparation. Typical analysis time is 5 min to 10 min per sample.
5.2 Excitation by monochromatic X-rays reduces background, simplifies matrix correction, and increases the signal/background ratio compared to polychromatic excitation used in conventional WDXRF techniques.3
5.3 Silicone oil defoamer can be added to coker feedstocks to minimize foaming in the coker. Residual silicon in the coker naphtha can adversely affect downstream catalytic processing of the naphtha. This test method provides a means to determine the silicon content of the naphtha.
5.4 Silicon contamination of gasoline, gasoline-ethanol blends, denatured ethanol, and their blends has led to fouled vehicle components (for example, spark plugs, exhaust oxygen sensors, catalytic converters) requiring parts replacement and repairs. Finished gasoline, gasoline-ethanol blends, and ethanol-fuel blends can come into contact with silicon a number of ways. Waste hydrocarbon solvents such as toluene can be added to gasoline. Such solvents can contain soluble silicon compounds. Silicon-based antifoam agents can be used in ethanol plants, which then pass silicon on to the finished ethanol-fuel blend. This test method can be used to determine if gasoline, gasoline-ethanol blends, and ethanol-fuel blends meet specifications with respect to silicon content of the fuel, and for resolution of customer problems.
5.5 Some silicon compounds covered by this test method are significantly more volatile than the silicon compounds typically used for the preparation of the calibration standards. Volatile compounds may not meet the stated precision from this test method because of selective loss of light materials during the analysis.
SCOPE
1.1 This test method covers the determination of total silicon by monochromatic, wavelength-dispersive X-ray fluorescence (MWDXRF) spectrometry in naphthas, gasoline, gasoline-ethanol blends, reformulated gasoline (RFG), ethanol and ethanol-fuel blends, and toluene at concentrations of 3 mg/kg to 100 mg/kg. The precision of this test method was determined by an interlaboratory study using representative samples of the liquids described in 1.1 and 1.2. The pooled limit of quantitation (PLOQ) was estimated to be 3 mg/kg.
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.
Note 2: Aromatic compounds such as toluene are under the jurisdiction of Committee D16 on Aromatic Hydrocarbons and Related Chemicals. However, toluene can be a contributor to silicon contamination in gasoline (see 5.4), thus its inclusion in this test method.
1.2 Gasoline samples containing ethanol and other oxygenates may 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 Annex A1 is applied to the results. The conditions for matrix matching and matrix correction are provided Section 6, Interferences.
1.3 Samples with silicon concentrations above 100 mg/kg can be analyzed after dilution with appropriate solvent. The precision and bias of silicon determinations on diluted samples have not been determined and may not be the same as shown for neat samples (Section 17).
1.4 A fundamental assumption in this test method is that the standard and sample matrices are well matched, or that the matrix differences are accounted for (see 14.5). Matrix mismatch can be caused by C/H ratio differences between samples and standards or by the presence of other interfering heteroatoms; observe the cautions and recommendations in Section 6.
1.5 The values stated in SI units are to be regarded as standard...
General Information
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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: D7757 − 22
Standard Test Method for
Silicon in Gasoline and Related Products by Monochromatic
1
Wavelength Dispersive X-ray Fluorescence Spectrometry
This standard is issued under the fixed designation D7757; 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* 1.5 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
1.1 This test method covers the determination of total
standard.
silicon by monochromatic, wavelength-dispersive X-ray fluo-
1.6 This standard does not purport to address all of the
rescence (MWDXRF) spectrometry in naphthas, gasoline,
safety concerns, if any, associated with its use. It is the
gasoline-ethanol blends, reformulated gasoline (RFG), ethanol
responsibility of the user of this standard to establish appro-
and ethanol-fuel blends, and toluene at concentrations of
priate safety, health, and environmental practices and deter-
3 mg⁄kg to 100 mg⁄kg. The precision of this test method was
mine the applicability of regulatory limitations prior to use.
determined by an interlaboratory study using representative
1.7 This international standard was developed in accor-
samples of the liquids described in 1.1 and 1.2. The pooled
dance with internationally recognized principles on standard-
limit of quantitation (PLOQ) was estimated to be 3 mg⁄kg.
ization established in the Decision on Principles for the
NOTE 1—Volatile samples such as high-vapor-pressure gasolines or
Development of International Standards, Guides and Recom-
light hydrocarbons might not meet the stated precision because of the
mendations issued by the World Trade Organization Technical
evaporation of light components during the analysis.
Barriers to Trade (TBT) Committee.
NOTE 2—Aromatic compounds such as toluene are under the jurisdic-
tion of Committee D16 on Aromatic Hydrocarbons and Related Chemi-
2. Referenced Documents
cals. However, toluene can be a contributor to silicon contamination in
gasoline (see 5.4), thus its inclusion in this test method. 2
2.1 ASTM Standards:
D4057 Practice for Manual Sampling of Petroleum and
1.2 Gasoline samples containing ethanol and other oxygen-
Petroleum Products
ates may be analyzed with this test method provided the matrix
D4175 Terminology Relating to Petroleum Products, Liquid
of the calibration standards is either matched to the sample
Fuels, and Lubricants
matrices or the matrix correction described in Annex A1 is
D4177 Practice for Automatic Sampling of Petroleum and
applied to the results. The conditions for matrix matching and
Petroleum Products
matrix correction are provided Section 6, Interferences.
D4806 Specification for Denatured Fuel Ethanol for Blend-
1.3 Samples with silicon concentrations above 100 mg⁄kg
ing with Gasolines for Use as Automotive Spark-Ignition
can be analyzed after dilution with appropriate solvent. The
Engine Fuel
precision and bias of silicon determinations on diluted samples
D5798 Specification for Ethanol Fuel Blends for Flexible-
have not been determined and may not be the same as shown
Fuel Automotive Spark-Ignition Engines
for neat samples (Section 17).
D6299 Practice for Applying Statistical Quality Assurance
and Control Charting Techniques to Evaluate Analytical
1.4 Afundamental assumption in this test method is that the
Measurement System Performance
standard and sample matrices are well matched, or that the
D6300 Practice for Determination of Precision and Bias
matrix differences are accounted for (see 14.5). Matrix mis-
Data for Use in Test Methods for Petroleum Products,
match can be caused by C/H ratio differences between samples
Liquid Fuels, and Lubricants
and standards or by the presence of other interfering heteroa-
D7343 Practice for Optimization, Sample Handling,
toms; observe the cautions and recommendations in Section 6.
Calibration, and Validation of X-ray Fluorescence Spec-
trometry Methods for Elemental Analysis of Petroleum
1
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
2
Subcommittee D02.03 on Elemental Analysis. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2022. Published December 2022. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2012. Last previous edition approved in 2017
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7757 − 17 D7757 − 22
Standard Test Method for
Silicon in Gasoline and Related Products by Monochromatic
1
Wavelength Dispersive X-ray Fluorescence Spectrometry
This standard is issued under the fixed designation D7757; 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*
1.1 This test method covers the determination of total silicon by monochromatic, wavelength-dispersive X-ray fluorescence
(MWDXRF) spectrometry in naphthas, gasoline, gasoline-ethanol blends, reformulated gasoline (RFG), ethanol and ethanol-fuel
blends, and toluene at concentrations of 3 mg ⁄kg to 100 mg ⁄kg. The precision of this test method was determined by an
interlaboratory study using representative samples of the liquids described in 1.1 and 1.2. The pooled limit of quantitation (PLOQ)
was estimated to be 3 mg ⁄kg.
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.
NOTE 2—Aromatic compounds such as toluene are under the jurisdiction of Committee D16 on Aromatic Hydrocarbons and Related Chemicals. However,
toluene can be a contributor to silicon contamination in gasoline (see 4.45.4), thus its inclusion in this test method.
1.2 Gasoline samples containing ethanol and other oxygenates may 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 Annex A1 is applied to the
results. The conditions for matrix matching and matrix correction are provided Section 56, Interferences.
1.3 Samples with silicon concentrations above 100 mg ⁄kg can be analyzed after dilution with appropriate solvent. The precision
and bias of silicon determinations on diluted samples have not been determined and may not be the same as shown for neat samples
(Section 1617).
1.4 A fundamental assumption in this test method is that the standard and sample matrices are well matched, or that the matrix
differences are accounted for (see 13.514.5). Matrix mismatch can be caused by C/H ratio differences between samples and
standards or by the presence of other interfering heteroatoms; observe the cautions and recommendations in Section 56.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.7 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.
1
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.
Current edition approved July 1, 2017Nov. 1, 2022. Published July 2017December 2022. Originally approved in 2012. Last previous edition approved in 20122017 as
D7757 – 12.D7757 – 17. DOI:10.1520/D7757-17.DOI:10.1520/D7757-22.
*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
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D7757 − 22
2. Referenced Documents
2
2.1 ASTM Standards:
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D4806 Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel
D5798 Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition Engines
D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Ana
...
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