1、Designation: D 2622 07An American National StandardStandard Test Method forSulfur in Petroleum Products by Wavelength DispersiveX-ray Fluorescence Spectrometry1This standard is issued under the fixed designation D 2622; the number immediately following the designation indicates the year oforiginal a
2、doption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense
3、.1. Scope*1.1 This test method covers the determination of total sulfurin petroleum and petroleum products that are single-phase andeither liquid at ambient conditions, liquefiable with moderateheat, or soluble in hydrocarbon solvents. These materials caninclude diesel fuel, jet fuel, kerosene, othe
4、r distillate oil,naphtha, residual oil, lubricating base oil, hydraulic oil, crudeoil, unleaded gasoline, gasohol and biodiesel.1.2 An estimate of this methods pooled limit of quantitation(PLOQ) is 3 mg/kg as calculated by the procedures in PracticeD 6259.1.2.1 The values of the limit of quantitatio
5、n (LOQ) andmethod precision for a specific laboratorys instrument dependson instrument source power (low or high power), sample type,and the practices established by the laboratory to perform themethod.1.3 Samples containing more than 4.6 mass % sulfur shouldbe diluted to bring the sulfur concentrat
6、ion of the dilutedmaterial within the scope of this test method. Samples that arediluted can have higher errors than indicated in Section 14 thannon-diluted samples.1.4 Volatile samples (such as high vapor pressure gasolinesor light hydrocarbons) may not meet the stated precisionbecause of selective
7、 loss of light materials during the analysis.1.5 A fundamental assumption in this test method is that thestandard and sample matrices are well matched, or that thematrix differences are accounted for (see 12.2). Matrix mis-match can be caused by C/H ratio differences between samplesand standards or
8、by the presence of other interfering heteroa-toms or species (see Table 1).1.6 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its
9、 use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD
10、4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 4294 Test Method for Sulfur in Petroleum and PetroleumProducts by Energy-Dispersive X-ray Fluorescence Spec-trometryD 4927 Test Methods for Elemental Analysis of Lubricantand Additive ComponentsBarium, Calcium, Phospho-rus, Sul
11、fur, and Zinc by Wavelength-Dispersive X-RayFluorescence SpectroscopyD 6259 Practice for Determination of a Pooled Limit ofQuantitationD 6299 Practice for Applying Statistical Quality AssuranceTechniques to Evaluate Analytical Measurement SystemPerformanceD 7343 Practice for Optimization, Sample Han
12、dling, Cali-bration, and Validation of X-Ray Fluorescence Spectrom-etry Methods for the Elemental Analysis of PetroleumProducts and LubricantsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications3. Summary of Test Method3.1 The sample is placed in the X-r
13、ay beam, and the peakintensity of the sulfur Ka line at 0.5373 nm is measured. Thebackground intensity, measured at a recommended wavelengthof 0.5190 nm (0.5437 nm for a Rh target tube) is subtractedfrom the peak intensity. The resultant net counting rate is thencompared to a previously prepared cal
14、ibration curve or equa-tion to obtain the concentration of sulfur in mg/kg or mass %(see Section 12).1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition appr
15、oved July 15, 2007. Published August 2007. Originallyapproved in 1967. Last previous edition approved in 2005 as D 262205.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, ref
16、er to the standards Document Summary page onthe ASTM website.1*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.4. Significance and Use4.1 This test method provides rapid
17、 and precise measure-ment of total sulfur in petroleum and petroleum products witha minimum of sample preparation. A typical analysis time is 1to 2 minutes per sample.4.2 The quality of many petroleum products is related to theamount of sulfur present. Knowledge of sulfur concentration isnecessary f
18、or processing purposes. There are also regulationspromulgated in federal, state, and local agencies that restrictthe amount of sulfur present in some fuels.4.3 This test method provides a means of determiningwhether the sulfur content of petroleum or a petroleum productmeets specification or regulat
19、ory limits.4.4 When this test method is applied to petroleum materialswith matrices significantly different from the white oil calibra-tion materials specified in this test method, the cautions andrecommendations in Section 5 should be observed wheninterpreting results.NOTE 1The equipment specified
20、for Test Method D 2622 tends to bemore expensive than that required for alternative test methods, such asTest Method D 4294. Consult the Index toASTM Standards for alternativetest methods.5. Interferences5.1 When the elemental composition (excluding sulfur) ofsamples differs significantly from the s
21、tandards, errors in thesulfur determination can result. For example, differences in thecarbon-hydrogen ratio of sample and calibration standardsintroduce errors in the determination. Some other interferencesand action levels are listed in Table 1. If a sample is knownfrom its history or another anal
22、ysis to contain any of thespecies listed in Table 1 at or above the values listed there, thatsample should be diluted with blank sulfur solvent to reducethe interferent concentration below the value to mitigate theeffect of this interference.NOTE 2The concentrations of substances in Table 1 were det
23、erminedby the calculation of the sum of the mass absorption coefficients timesmass fraction of each element present. This calculation was made fordilutions of representative samples containing approximately 3 % ofinterfering substances and 0.5 % sulfur.5.2 Fuels containing large quantities of ethano
24、l or methanol(see Table 1) have a high oxygen content leading to significantabsorption of sulfur Ka radiation and low sulfur results. Suchfuels can, however, be analyzed using this test method pro-vided either that correction factors are applied to the results(when calibrating with white oils) or th
25、at the calibrationstandards are prepared to match the matrix of the sample. See11.5.5.3 In general, petroleum materials with compositions thatvary from white oils as specified in 9.1 can be analyzed withstandards made from base materials that are of the same orsimilar composition. Thus a gasoline ma
26、y be simulated bymixing isooctane and toluene in a ratio that approximates theexpected aromatic content of the samples to be analyzed.Standards made from this simulated gasoline can produceresults that are more accurate than results obtained using whiteoil standards.5.4 Test Method D 4927 is the rec
27、ommended test methodfor the determination of sulfur 100 mg/kg in lubricating oilsand lubricating oil additives because method D 4927 imple-ments inter-element correction factors. Method D 2622 is notsuitable because it does not encompass the measurement of theadditional elements present in lubricati
28、ng oils and their addi-tives making matrix correction impossible.6. Apparatus6.1 Wavelength Dispersive X-Ray Fluorescence Spectrom-eter (WDXRF), equipped for X-ray detection in the wavelengthrange from about 0.52 nm to about 0.55 nm (specifically at0.537 nm). For optimum sensitivity to sulfur, the i
29、nstrumentshould be equipped with the following items:6.1.1 Optical Path, vendor specified, helium preferred, am-bient air or nitrogen are inferior.6.1.2 Pulse-Height Analyzer, or other means of energydiscrimination.6.1.3 Detector, for the detection of X-rays with wavelengthsin the range of interest
30、(from about 0.52 nm to about 0.55 nm).6.1.4 Analyzing Crystal, suitable for the dispersion of sulfurKa and background X-rays within the angular range of thespectrometer employed. Germanium or pentaerythritol (PET)are generally found to be acceptable. Other crystals may beused, consult with the instr
31、ument vendor.6.1.5 X-ray Tube, capable of exciting sulfur Ka radiation.Tubes with anodes of rhodium, chromium, and scandium aremost popular although other anodes can be used.NOTE 3Exposure to excessive quantities of high energy radiationsuch as those produced by X-ray spectrometers is injurious to h
32、ealth. Theoperator needs to take appropriate actions to avoid exposing any part oftheir body, not only to primary X-rays, but also to secondary or scatteredradiation that might be present. The X-ray spectrometer should beoperated in accordance with the regulations governing the use of ionizingradiat
33、ion.6.2 Analytical Balance, capable of weighing to the nearest0.1 mg and up to 100 g.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of
34、 the American Chemical Society whereTABLE 1 Concentrations of Interfering SpeciesElement Mass % ToleratedPhosphorus 0.3Zinc 0.6Barium 0.8Lead 0.9Calcium 1Chlorine 3Oxygen 2.8FAME (see Note 15)25Ethanol (see Note 15)8.6Methanol (see Note 15)6D2622072such specifications are available.3Other grades may
35、 be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.2 Di-n-Butyl Sulfide (DBS), a high-purity material with acertified analysis for sulfur content. Use the certified sulfurcontent and the mate
36、rial purity when calculating the exactconcentrations of the calibration standards (see 9.1).(WarningDi-n-butyl sulfide is flammable and toxic. Pre-pared solutions may not be stable several months after prepa-ration.)NOTE 4It is essential to know the concentration of sulfur in thedi-n-butyl sulfide,
37、not only the purity, since impurities may also be sulfurcontaining compounds. The sulfur content may be determined via massdilution in sulfur-free white oil followed by a direct comparison analysisagainst NIST (or other primary standards body) reference materials.7.3 Drift Correction Monitor(s) (Opt
38、ional), Several differ-ent materials have been found to be suitable for use as driftcorrection monitors. Appropriate drift monitor samples shouldbe permanent materials that are stable with respect to repeatedexposure to X-rays. Stable liquids like polysulfide oils, glass ormetallic specimens are rec
39、ommended. Liquids, pressed pow-ders, and solid materials that degrade with repeated exposure toX-rays should not be used. Examples of sulfur containingmaterials that have been found to be suitable include arenewable liquid petroleum material, a metal alloy, or a fusedglass disk. The monitors countin
40、g rate, in combination withcount time, shall be sufficient to give a relative counting errorof less than 1 %. The counting rate for the monitor sample isdetermined during calibration (see 9.4) and again at the time ofanalysis (see 10.1). These counting rates are used to calculatea drift correction f
41、actor (see 11.1).7.3.1 Drift correction is usually implemented automaticallyin software, although the calculation can readily be donemanually. For X-ray instruments that are highly stable, themagnitude of the drift correction factor may not differ signifi-cantly from unity.7.4 Polysulfide Oil, gener
42、ally nonyl polysulfides containinga known percentage of sulfur diluted in a hydrocarbon matrix.(WarningMay cause allergic skin reactions.)NOTE 5Polysulfide oils are high molecular weight oils that containhigh concentrations of sulfur, as high as 50 weight percent. They exhibitexcellent physical prop
43、erties such as low viscosity, low volatility, anddurable shelf life while being completely miscible in white oil. Polysulfideoils are readily available commercially. The sulfur content of the polysul-fide oil concentrate is determined via mass dilution in sulfur-free white oilfollowed by a direct co
44、mparison analysis against NIST (or other primarystandards body) reference materials.7.5 Mineral Oil, White (MOW), ACS Reagent Grade con-taining less than 2 mg/kg sulfur or other suitable base materialcontaining less than 2 mg/kg sulfur. When low level (1KW source) instruments are also included.14.2
45、BiasThe interlaboratory study6included ten NISTstandard reference materials (SRMs). The certified sulfurvalue, interlaboratory round robin (RR) value, measured C/H,apparent bias, and relative bias are given in Table 5. Table 6compares NIST value with sulfur concentrations corrected forC/H ratio. The
46、 white oil was assumed to have a C/H mass ratioof 5.698 (C22H46).14.2.1 The variation in relative sulfur sensitivity as afunction of C/H mass ratio is shown graphically in Fig. 1.14.2.2 Based on the analysis of 10 NIST Standard Refer-ence Materials (SRMs), there was no significant bias betweenthe ce
47、rtified values and the results obtained in this interlabo-ratory study for any SRM or sample type within measuredreproducibilities (R), especially after the C/H ratio correctionswere applied (see Tables 5 and 6).15. Keywords15.1 analysis; diesel; gasoline; jet fuel; kerosene; petro-leum; spectrometr
48、y; sulfur; wavelength dispersive x-ray fluo-rescence; X-rayTABLE 5 Comparison of NIST SRM Data and ASTM Interlaboratory Study (RR) Measured ResultsNISTSRMNumberSulfur,mg/kg,NISTRRSampleNumberMatrixAverage Measuredmg/kg SulfurASTM RRMeasured Reproducibilitymg/kg SulfurASTM RRMeasured Biasmg/kg Sulfur
49、Relative MeasuredBias, %2298 4.7 1 Gasoline 6.0 2.9 1.3 27.72723a 11.0 5 Diesel 10.1 3.6 -0.9 -8.182299 13.6 3 Gasoline 14.2 3.8 0.6 4.412296 40.0 2 Gasoline 40.2 6.6 0.2 0.52770 41.6 7 Diesel 42.1 6.8 0.5 1.202724b 426.5 8 Diesel 420.9 42.5 -5.6 -1.312722 2103 10 Crude Oil 2054 181 -49 -2.331619b 6960 12 Residual Fuel Oil 6448 546 -512 -7.362721 15830 9 Crude Oil 15884 1170 54 0.341620c 45610 13 Residual Fuel Oil 44424 3123 -1186 -2.60TABLE 6 Comparison of NIST SRM Data and ASTM Interlaboratory Study (RR) Results Corrected for C/H RatioUsing Mineral Oil StandardsNISTSRM
