1、Designation: D7039 13D7039 15Standard Test Method forSulfur in Gasoline, Diesel Fuel, Jet Fuel, Kerosine,Biodiesel, Biodiesel Blends, and Gasoline-Ethanol Blendsby Monochromatic Wavelength Dispersive X-rayFluorescence Spectrometry1This standard is issued under the fixed designation D7039; the number
2、 immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.
3、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-e
4、thanol blends.NOTE 1Volatile samples such as high-vapor-pressure gasolines or light hydrocarbons might not meet the stated precision because of the evaporationof light components during the analysis.1.2 The range of this test method is between the pooled limit of quantitation (PLOQ) value (calculate
5、d by procedures consistentwith Practice D6259) of 3.23.2 mg mg/kg kg total sulfur and the highest level sample in the round robin, 28222822 mg mg/kgkg total sulfur.1.3 Samples containing oxygenates can be analyzed with this test method provided the matrix of the calibration standards iseither matche
6、d to the sample matrices or the matrix correction described in Section 5 or Annex A1 is applied to the results. Theconditions for matrix matching and matrix correction are provided in the Interferences section (Section 5).1.4 Samples with sulfur content above 28222822 mg mg/kg kg can be analyzed aft
7、er dilution with appropriate solvent (see5.4).The precision and bias of sulfur determinations on diluted samples has not been determined and may not be the same as shownfor neat samples (Section 15).1.5 When the elemental composition of the samples differ significantly from the calibration standards
8、 used to prepare thecalibration 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 saf
9、ety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For specific hazard information, see 3.1.2. Referenced Documents2.1 ASTM Sta
10、ndards:2D4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD6259 Practice for Determination of a Pooled Limit of QuantitationD6299 Practice for Applying Statistical Quality Assurance and Control Charting Tech
11、niques to Evaluate Analytical Measure-ment System PerformanceD6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants2.2 EPA Documents:340 CFR 80.584 Code of Federal Regulations; Title 40; Part 80; U.S. Environmental Agency, July 1, 20
12、051 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved Sept. 15, 2013April 1, 2015. Published October 2013May 2015. Originally approv
13、ed in 2004. Last previous edition approved in 20072013 asD7039 07.D7039 13. DOI: 10.1520/D7039-13.10.1520/D7039-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to th
14、e standards Document Summary page on the ASTM website.3 Available from U.S. Government Printing Office, 732 N. Capitol Street, NW, Washington, DC 20401.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 t
15、he previous version. Becauseit 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 versionof the standard as published by ASTM is to be considered the official document.*A Summary
16、 of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Summary of Test Method3.1 A monochromatic X-ray beam with a wavelength suitable to excite the K-shell electrons of sulfur is foc
17、used onto a testspecimen contained in a sample cell (see Fig. 1). The fluorescent K radiation at 0.5373 nm (5.373 ) emitted by sulfur is collectedby a fixed monochromator (analyzer). The intensity (counts per second) of the sulfur X rays is measured using a suitable detectorand converted to the conc
18、entration of sulfur (mg/kg) in a test specimen using a calibration equation. Excitation by monochromaticX rays reduces background, simplifies matrix correction, and increases the signal/background ratio compared to polychromaticexcitation used in conventional WDXRF techniques.4 (WarningExposure to e
19、xcessive quantities of X-ray radiation is injuriousto health. The operator needs to take appropriate actions to avoid exposing any part of his/her body, not only to primary X rays,but also to secondary or scattered radiation that might be present. The X-ray spectrometer should be operated in accorda
20、nce withthe regulations governing the use of ionizing radiation.)4. Significance and Use4.1 This test method provides for the precise measurement of the total sulfur content of samples within the scope of this testmethod with minimal sample preparation and analyst involvement. The typical time for e
21、ach analysis is five minutes.4.2 Knowledge of the sulfur content of diesel fuels, gasolines, and refinery process streams used to blend gasolines is importantfor process control as well as the prediction and control of operational problems such as unit corrosion and catalyst poisoning, andin the ble
22、nding of products to commodity specifications.4.3 Various federal, state, and local agencies regulate the sulfur content of some petroleum products, including gasoline anddiesel fuel. Unbiased and precise determination of sulfur in these products is critical to compliance with regulatory standards.5
23、. Interferences5.1 Differences between the elemental composition of test samples and the calibration standards can result in biased sulfurdeterminations. For samples within the scope of this test method, elements contributing to bias resulting from differences in thematrices of calibrants and test s
24、amples are hydrogen, carbon, and oxygen. A matrix-correction factor (C) can be used to correctthis bias; the calculation is described in AnnexA1. For general analytical purposes, the matrices of test samples and the calibrantsare considered to be matched when the calculated correction factor C is wi
25、thin 0.98 to 1.04. No matrix correction is required withinthis range. A matrix correction is required when the value of C is outside the range of 0.98 to 1.04. For most testing, matrixcorrection can be avoided with a proper choice of calibrants. For example, based on the example graph in Annex A1 (F
26、ig. 2), acalibrant with 86 mass % carbon and 14 mass % hydrogen can cover non-oxygen containing samples with C/H ratios from 5.4to 8.5. For gasolines with oxygenates, up to 2.3 mass % oxygen (12 mass % MTBE) can be tolerated for test samples with thesame C/H ratio as the calibrants.5.2 Fuels contain
27、ing large quantities of oxygenates, such as biodiesel, biodiesel blends, and gasoline-ethanol blends, can havea high oxygen content leading to significant absorption of sulfur K radiation and low sulfur results.5.2.1 Biodiesel and biodiesel blends may be analyzed using this test method by applying c
28、orrection factors to the results or usingcalibration standards that are matrix-matched to the test sample (see Table 1). Correction factors may be calculated (see AnnexA1), or obtained from Table 2 if the sample has been measured on a mineral oil calibration curve.4 Bertin, E. P., Principles and Pra
29、ctices of X-ray Spectrometric Analysis , Plenum Press, New York, 1975, pp. 115-118.Bertin, E. P., Principles and Practices of X-raySpectrometric Analysis , Plenum Press, New York, 1975, pp. 115118.FIG. 1 Schematic of the MWDXRF AnalyzerD7039 1525.2.2 Gasoline-ethanol blends may be analyzed using thi
30、s test method by applying correction factors to the results or usingcalibration standards that are matrix matched to the test sample (see Table 1). Correction factors may be calculated (see AnnexA1), or obtained from the correction tables. Use Table 3 if the sample has been measured on a mineral oil
31、 calibration curve, oruse Table 4 if the sample has been measured on an ethanol calibration curve. Ethanol-based calibrants can be used forgasoline-ethanol blends. Ethanol-based calibrants are recommended for gasoline-ethanol blends containing more than 50 % (byvolume) ethanol.5.3 Other samples havi
32、ng interferences as described in 5.1 may be analyzed using this test method by applying correctionfactors to the results or by using calibration standards that are matrix matched to the test sample (see Table 1). Correction factorsmay be calculated as described in Annex A1.5.4 To minimize any bias i
33、n the results, use calibration standards prepared from sulfur-free base materials of the same or similarelemental composition as the test samples. When diluting samples, use a diluent with an elemental composition the same or similarto the base material used for preparing the calibration standards.5
34、.4.1 Abase material for gasoline can be approximately simulated by mixing 2,2,4-trimethylpentane (isooctane) and toluene ina ratio that approximates the expected aromatic content of the samples to be analyzed.6. Apparatus6.1 Monochromatic Wavelength Dispersive X-ray Fluorescence (MWDXRF) Spectromete
35、r5,equipped for X-ray detection at0.5373 nm (5.373). Any spectrometer of this type can be used if it includes the following features, and the precision and biasof test results are in accordance with the values described in Section 15.5 The sole source of this apparatus known to the committee at this
36、 time is X-ray Optical Systems, Inc., 15 Tech Valley Drive, East Greenbush, NY 12061. If you are awareof alternative suppliers, please provide this information toASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee, which
37、 you may attend.FIG. 2 Matrix Correction for a Test Sample vs. C/H and Total Oxygen Content Using Chromium K for the Excitation BeamTABLE 1 Methods for Interference Correction by Sample TypeSample TypeCorrectionTables (Table2, Table 3,Table 4, orN/A)CorrectionCalculation(Annex A1)MatrixMatchingBiodi
38、esel and Biodiesel Blends 2 Yes YesGasoline-ethanol Blends 3 or 4 Yes YesAll Other Sample Types N/A Yes YesD7039 1536.1.1 X-ray Source, capable of producing X rays to excite sulfur. X-ray tubes with a power 25W capable of producing Rh L,Pd L, Ag L, Ti K, Sc K, and Cr K radiation are recommended for
39、this purpose.6.1.2 Incident-beam Monochromator, capable of focusing and selecting a single wavelength of characteristic X rays from thesource onto the specimen.6.1.3 Optical Path, designed to minimize the absorption along the path of the excitation and fluorescent beams using a vacuumor a helium atm
40、osphere. A vacuum of 2.7 kPa (20 Torr) is recommended. The calibration and test measurements must be donewith identical optical paths, including vacuum or helium pressure.6.1.4 Fixed-channel Monochromator, suitable for dispersing sulfur K X rays.6.1.5 Detector, designed for efficient detection of su
41、lfur K X rays.6.1.6 Single-Channel Analyzer, an energy discriminator to monitor only sulfur radiation.6.1.7 Removable Sample Cell, an open-ended specimen holder compatible with the geometry of the MWDXRF spectrometerand designed to use replaceable X-ray transparent film (see 6.1.8) to hold a liquid
42、specimen with a minimum depth of 5mm.5 mm.The sample cell must not leak when fitted with X-ray transparent film. A disposable cell is recommended.6.1.8 X-Ray Transparent Film, for containing and supporting the test specimen in the sample cell (see 6.1.7) while providinga low-absorption window for X
43、rays to pass to and from the sample. Any film resistant to chemical attack by the sample, free ofsulfur, and X-ray transparent can be used, for example, polyester, polypropylene, polycarbonate, and polyimide. However, samplesof high aromatic content can dissolve polyester and polycarbonate films.7.
44、Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchTABLE 2 Correction Factors for
45、Biodiesel Blends Measured on a Mineral Oil Calibration CurveNOTE 1Determine the correction factor in the table below by finding the known oxygen content of the test specimen (for example, 11 wt %) as thesum of the value in the first column and the value in the first row (for example, 11 = 10+1). The
46、 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 1.156610 % 1.1740 1.1914 1.2088 1.2262 1.2436 1.2610 1.2784 1
47、.2958 1.3132 1.3306TABLE 3 Correction Factors for Gasoline-ethanol Blends Measured on a Mineral Oil Calibration CurveNOTE 1Determine the correction factor in the table below by finding the known ethanol content of the test specimen (for example, 15 vol %) as thesum of the value in the first column a
48、nd 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
49、1.049110 % 1.0556 1.0621 1.0686 1.0751 1.0816 1.0881 1.0945 1.1009 1.1073 1.113720 % 1.1201 1.1265 1.1328 1.1391 1.1455 1.1518 1.1580 1.1643 1.1706 1.176830 % 1.1830 1.1892 1.1954 1.2016 1.2077 1.2139 1.2200 1.2261 1.2322 1.238340 % 1.2444 1.2504 1.2565 1.2625 1.2685 1.2745 1.2805 1.2865 1.2924 1.298450 % 1.3043 1.3102 1.3161 1.3220 1.3279 1.3337 1.3396 1.3454 1.3512 1.357060 % 1.3628 1.3686 1.3743 1.3801 1.3858 1.3915 1.3972 1.4029 1.4086 1.414370 % 1.4199 1.4256 1.4312 1.4368 1.4424 1.4480 1.4536 1.4591 1.4647 1.470280 % 1.4757 1.4813 1.4868 1.4922 1.49
