1、Designation: D2622 10Standard Test Method forSulfur in Petroleum Products by Wavelength DispersiveX-ray Fluorescence Spectrometry1This standard is issued under the fixed designation D2622; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method c
3、overs 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, other distillate oil,naphtha, residu
4、al oil, lubricating base oil, hydraulic oil, crudeoil, unleaded gasoline, gasohol and biodiesel.1.2 The range of this test method is between the PLOQvalue (calculated by procedures consistent with PracticeD6259) of 3 mg/kg total sulfur and the highest level sample inthe round robin, 4.6 wt. % total
5、sulfur.NOTE 1Instrumentation covered by this test method can vary insensitivity. The applicability of the test method at sulfur concentrationsbelow 3 mg/kg may be determined on an individual basis for WDXRFinstruments capable of measuring lower levels, but precision in this testmethod does not apply
6、.1.2.1 The values of the limit of quantitation (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 sh
7、ouldbe diluted to bring the sulfur concentration 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
8、meet the stated precisionbecause of selective 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
9、 differences between samplesand standards or 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 asstandard. No other units of measurement are included in thisstandard.1.7 This standard does not purport to address all of the
10、safety concerns, if any, associated with its 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:2D4057 Practice for Manual Sa
11、mpling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4294 Test Method for Sulfur in Petroleum and PetroleumProducts by Energy Dispersive X-ray Fluorescence Spec-trometryD4927 Test Methods for Elemental Analysis of Lubricantand Additive Com
12、ponentsBarium, Calcium, Phospho-rus, Sulfur, and Zinc by Wavelength-Dispersive X-RayFluorescence Spectroscopy1This 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 edit
13、ion approved Feb. 15, 2010. Published March 2010. Originallyapproved in 1967. Last previous edition approved in 2008 as D262208. DOI:10.1520/D2622-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
14、ards volume information, refer to the standards Document Summary page onthe ASTM website.TABLE 1 Concentrations of Interfering SpeciesSpecies Mass % ToleratedPhosphorus 0.3Zinc 0.6Barium 0.8Lead 0.9Calcium 1Chlorine 3Oxygen 2.8FAME (see Note 16)25Ethanol (see Note 16)8.6Methanol (see Note 16)61*A Su
15、mmary 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.D6259 Practice for Determination of a Pooled Limit ofQuantitationD6299 Practice for Applying Statistical Quality Assuranceand
16、 Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD7343 Practice for Optimization, Sample Handling, Cali-bration, and Validation of X-ray Fluorescence Spectrom-etry Methods for Elemental Analysis of Petroleum Prod-ucts and LubricantsE29 Practice for Using Significant D
17、igits in Test Data toDetermine Conformance with Specifications3. Summary of Test Method3.1 The sample is placed in the X-ray 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 targe
18、t tube) is subtractedfrom the peak intensity. The resultant net counting rate is thencompared to a previously prepared calibration curve or equa-tion to obtain the concentration of sulfur in mg/kg or mass %(see Section 12).4. Significance and Use4.1 This test method provides rapid and precise measur
19、e-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 for processing purpo
20、ses. 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 regulatory limits.4.4 When
21、 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 2The equipment specified for Test Method D26
22、22 tends to bemore expensive than that required for alternative test methods, such asTest Method D4294. Consult the Index toASTM Standards for alternativetest methods.5. Interferences5.1 When the elemental composition (excluding sulfur) ofsamples differs significantly from the standards, errors in t
23、hesulfur 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 analysis to contain any o
24、f 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 3The concentrations of the first seven substances in Table 1were determine
25、d by the calculation of the sum of the mass absorptioncoefficients times mass fraction of each element present. This calculationwas made for dilutions of representative samples containing approxi-mately 3 % of interfering substances and 0.5 % sulfur. Refer to Note 16for additional information regard
26、ing FAME, ethanol, and methanol.5.2 Fuels containing large quantities of FAME, ethanol, ormethanol (see Table 1) have a high oxygen content leading tosignificant absorption of sulfur Ka radiation and low sulfurresults. Such fuels can, however, be analyzed using this testmethod provided either that c
27、orrection factors are applied tothe results (when calibrating with white oils) or that thecalibration standards are prepared to match the matrix of thesample. See 11.5.5.3 In general, petroleum materials with compositions thatvary from white oils as specified in 9.1 can be analyzed withstandards mad
28、e from base materials that are of the same orsimilar composition. Thus a gasoline may 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 accur
29、ate than results obtained using whiteoil standards.5.4 Test Method D4927 is the recommended test method forthe determination of sulfur 100 mg/kg in lubricating oils andlubricating oil additives because method D4927 implementsinter-element correction factors. Method D2622 is not suitablebecause it do
30、es not encompass the measurement of the addi-tional elements present in lubricating oils and their additivesmaking 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 ab
31、out 0.55 nm (specifically at0.537 nm). For optimum sensitivity to sulfur, the instrumentshould 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
32、Detector, for the detection of X-rays with wavelengthsin the range of interest (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 gene
33、rally found to be acceptable. Other crystals may beused, consult with the instrument 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 4Exposure to excessive quantities of high
34、energy radiationsuch as those produced by X-ray spectrometers is injurious to health. 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 be
35、operated in accordance with the regulations governing the use of ionizingradiation.6.2 Analytical Balance, capable of weighing to the nearest0.1 mg and up to 100 g.D2622 1027. Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended
36、thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening
37、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 material purity when calculating the exactconcentrations of the calibration standards (see 9.1).(WarningDi-n-butyl sulfide is fla
38、mmable and toxic. Pre-pared solutions may not be stable several months after prepa-ration.)NOTE 5It is essential to know the concentration of sulfur in thedi-n-butyl sulfide, not only the purity, since impurities may also be sulfurcontaining compounds. The sulfur content may be determined via massdi
39、lution 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) (Optional), Several differ-ent materials have been found to be suitable for use as driftcorrection monitors. Appropriate drift mo
40、nitor samples shouldbe permanent materials that are stable with respect to repeatedexposure to X-rays. Stable liquids like polysulfide oils, glass ormetallic specimens are recommended. Liquids, pressed pow-ders, and solid materials that degrade with repeated exposure toX-rays should not be used. Exa
41、mples of sulfur containingmaterials that have been found to be suitable include arenewable liquid petroleum material, a metal alloy, or a fusedglass disk. The monitors counting rate, in combination withcount time, shall be sufficient to give a relative counting errorof less than 1 %. The counting ra
42、te 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 factor (see 11.1).7.3.1 Drift correction is usually implemented automaticallyin software, although the calculation can readily
43、 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, generally nonyl polysulfides containinga known percentage of sulfur diluted in a hydrocarbon matrix.(WarningMay cause allergic ski
44、n reactions.)NOTE 6Polysulfide oils are high molecular weight oils that containhigh concentrations of sulfur, as high as 50 weight percent. They exhibitexcellent physical properties such as low viscosity, low volatility, anddurable shelf life while being completely miscible in white oil. Polysulfide
45、oils 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 comparison analysis against NIST (or other primarystandards body) reference materials.7.5 Mineral Oil, White (MOW), ACS Reagent
46、 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 BiasThe interlaboratory study6included ten NISTstandard reference materials (SRMs). The certified sulfurvalue, interlaborator
47、y 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 white oil was assumed to have a C/H mass ratioof 5.698 (C22H46).14.2.1 The variation in relative sulfur sensitivity as afunc
48、tion of C/H mass ratio is shown graphically in Fig. 1.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1622.TABLE 5 Comparison of NIST SRM Data and ASTM Interlaboratory Study (RR) Measured ResultsNISTSRMNumberSulfur,mg/kg,NIS
49、TRRSampleNumberMatrixAverage Measuredmg/kg SulfurASTM RRMeasured Reproducibilitymg/kg SulfurASTM RRMeasured Biasmg/kg SulfurRelative 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 Comp
