1、Designation: D2622 10D2622 16Standard 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
2、 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This
3、test method covers the determination of total sulfur in petroleum and petroleum products that are single-phase andeither liquid at ambient conditions, liquefiable with moderate heat, or soluble in hydrocarbon solvents. These materials can includediesel fuel, jet fuel, kerosene, other distillate oil,
4、 naphtha, residual oil, lubricating base oil, hydraulic oil, crude oil, unleadedgasoline, gasohol gasoline-ethanol blends, and biodiesel.1.2 The range of this test method is between the PLOQ value (calculated by procedures consistent with Practice D6259) of 3mg/kg total sulfur and the highest level
5、sample in the round robin, 4.6 wt. %weight % total sulfur.NOTE 1Instrumentation covered by this test method can vary in sensitivity. The applicability of the test method at sulfur concentrations below 33 mg mg/kg kg may be determined on an individual basis for WDXRF instruments capable of measuring
6、lower levels, but precision in this test method doesnot apply.1.2.1 The values of the limit of quantitation (LOQ) and method precision for a specific laboratorys instrument depends oninstrument source power (low or high power), sample type, and the practices established by the laboratory to perform
7、the method.1.3 Samples containing more than 4.6 mass % sulfur should be diluted to bring the sulfur concentration of the diluted materialwithin the scope of this test method. Samples that are diluted can have higher errors than indicated in Section 14 than non-dilutedsamples.1.4 Volatile samples (su
8、ch as high vapor pressure gasolines or light hydrocarbons) may not meet the stated precision becauseof selective loss of light materials during the analysis.1.5 A fundamental assumption in this test method is that the standard and sample matrices are well matched, or that the matrixdifferences are a
9、ccounted for (see 12.2). Matrix mismatch can be caused by C/H ratio differences between samples and standardsor by the presence of other interfering heteroatoms or species (see Table 1).1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in th
10、is standard.1 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 Feb. 15, 2010Jan. 1, 2016. Published March 2010February 2016. Origin
11、ally approved in 1967. Last previous edition approved in 20082010 asD2622D2622 10.08. DOI: 10.1520/D2622-10.10.1520/D2622-16.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 Not
12、e 16) 8.6Methanol (see Note 16) 6This 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. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recomm
13、ends 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 of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700
14、, West Conshohocken, PA 19428-2959. United States11.7 This standard does not purport to address all of the safety 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 re
15、gulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD4294 Test Method for Sulfur in Petroleum and Petroleum Products by Energy Disper
16、sive X-ray Fluorescence SpectrometryD4927 Test Methods for Elemental Analysis of Lubricant and Additive ComponentsBarium, Calcium, Phosphorus, Sulfur,and Zinc by Wavelength-Dispersive X-Ray Fluorescence SpectroscopyD6259 Practice for Determination of a Pooled Limit of Quantitation for a Test MethodD
17、6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-ment System PerformanceD7343 Practice for Optimization, Sample Handling, Calibration, and Validation of X-ray Fluorescence Spectrometry Methodsfor Elemental Analysis of Petroleum P
18、roducts and LubricantsE29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications3. Summary of Test Method3.1 The sample is placed in the X-ray beam, and the peak intensity of the sulfur K line at 0.5373 nm 0.5373 nm is measured.The background intensity, measu
19、red at a recommended wavelength of 0.5190 nm (0.5437 nm 0.5190 nm (0.5437 nm for a Rhtarget tube) is subtracted from the peak intensity. The resultant net counting rate is then compared to a previously preparedcalibration curve or equation to obtain the concentration of sulfur in mg/kg or mass %mill
20、igrams per kilogram (mg/kg) ormass percent (see Section 12).4. Significance and Use4.1 This test method provides rapid and precise measurement of total sulfur in petroleum and petroleum products with aminimum of sample preparation. A typical analysis time is 11 min to 2 minutes 2 min per sample.4.2
21、The quality of many petroleum products is related to the amount of sulfur present. Knowledge of sulfur concentration isnecessary for processing purposes. There are also regulations promulgated in federal, state, and local agencies that restrict theamount of sulfur present in some fuels.4.3 This test
22、 method provides a means of determining whether the sulfur content of petroleum or a petroleum product meetsspecification or regulatory limits.4.4 When this test method is applied to petroleum materials with matrices significantly different from the white oil calibrationmaterials specified in this t
23、est method, the cautions and recommendations in Section 5 should be observed when interpretingresults.NOTE 2The equipment specified for Test Method D2622 tends to be more expensive than that required for alternative test methods, such as TestMethod D4294. Consult the Index to ASTM Standards for alte
24、rnative test methods.5. Interferences5.1 When the elemental composition (excluding sulfur) of samples differs significantly from the standards, errors in the sulfurdetermination can result. For example, differences in the carbon-hydrogen ratio of sample and calibration standards introduceerrors in t
25、he determination. Some other interferences and action levels are listed in Table 1. If a sample is known from its historyor another analysis to contain any of the species listed in Table 1 at or above the values listed there, that sample should be dilutedwith blank sulfur solvent to reduce the inter
26、ferent concentration below the value to mitigate the effect of this interference.NOTE 3The concentrations of the first seven substances in Table 1 were determined by the calculation of the sum of the mass absorption coefficientstimes mass fraction of each element present. This calculation was made f
27、or dilutions of representative samples containing approximately 3 % ofinterfering substances and 0.5 % sulfur. Refer to Note 16 for additional information regarding FAME, ethanol, and methanol.5.2 Fuels containing large quantities of FAME, ethanol, or methanol (see Table 1) have a high oxygen conten
28、t leading tosignificant absorption of sulfur K radiation and low sulfur results. Such fuels can, however, be analyzed using this test methodprovided either that correction factors are applied to the results (when calibrating with white oils) or that the calibration standardsare prepared to match the
29、 matrix of the sample. See 11.5.5.3 In general, petroleum materials with compositions that vary from white oils as specified in 9.1 can be analyzed withstandards made from base materials that are of the same or similar composition. Thus a gasoline may be simulated by mixing2 For referencedASTM stand
30、ards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.D2622 162isooctane and toluene in a ratio that approximates the expected aromatic conte
31、nt of the samples to be analyzed. Standards madefrom this simulated gasoline can produce results that are more accurate than results obtained using white oil standards.5.4 Test Method D4927 is the recommended test method for the determination of sulfur 100100 mg mg/kg kg in lubricatingoils and lubri
32、cating oil additives because method D4927 implements inter-element correction factors. Test Method D2622 is notsuitable because it does not encompass the measurement of the additional elements present in lubricating oils and their additivesmaking matrix correction impossible.6. Apparatus6.1 Waveleng
33、th Dispersive X-Ray Fluorescence Spectrometer (WDXRF), equipped for X-ray detection in the wavelength rangefrom about 0.52 nm 0.52 nm to about 0.55 nm 0.55 nm (specifically at 0.537 nm). 0.537 nm). For optimum sensitivity to sulfur,the instrument should be equipped with the following items:6.1.1 Opt
34、ical Path, vendor specified, helium preferred, ambient air or nitrogen are inferior.6.1.2 Pulse-Height Analyzer, or other means of energy discrimination.6.1.3 Detector, for the detection of X-rays with wavelengths in the range of interest (from about 0.52 nm 0.52 nm to about 0.55nm).0.55 nm).6.1.4 A
35、nalyzing Crystal, suitable for the dispersion of sulfur K and background X-rays within the angular range of thespectrometer employed. Germanium or pentaerythritol (PET) are generally found to be acceptable. Other crystals may be used,consult with the instrument vendor.6.1.5 X-ray Tube, capable of ex
36、citing sulfur K radiation. Tubes with anodes of rhodium, chromium, and scandium are mostpopular although other anodes can be used.NOTE 4Exposure to excessive quantities of high energy radiation such as those produced by X-ray spectrometers is injurious to health. The operatorneeds to take appropriat
37、e actions to avoid exposing any part of their body, not only to primary X-rays, but also to secondary or scattered radiation thatmight be present. The X-ray spectrometer should be operated in accordance with the regulations governing the use of ionizing radiation.6.2 Analytical Balance, capable of w
38、eighing to the nearest 0.1 mg 0.1 mg and up to 100 g.100 g.7. Reagents7.1 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 S
39、ociety where suchspecifications are available.3 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purityto permit its use without lessening the accuracy of the determination.7.2 Di-n-Butyl Sulfide (DBS), a high-purity material with a certified analys
40、is for sulfur content. Use the certified sulfur contentand the material purity when calculating the exact concentrations of the calibration standards (see 9.1). (WarningDi-n-butylsulfide is flammable and toxic. Prepared solutions may not be stable several months after preparation.)NOTE 5It is essent
41、ial to know the concentration of sulfur in the di-n-butyl sulfide, not only the purity, since impurities may also be sulfur containingcompounds. The sulfur content may be determined via mass dilution in sulfur-free white oil followed by a direct comparison analysis against NIST (orother primary stan
42、dards body) reference materials.7.3 Drift Correction Monitor(s) (Optional), Several different materials have been found to be suitable for use as drift correctionmonitors. Appropriate drift monitor samples should be permanent materials that are stable with respect to repeated exposure toX-rays. Stab
43、le liquids like polysulfide oils, glass, or metallic specimens are recommended. Liquids, pressed powders, and solidmaterials that degrade with repeated exposure to X-rays should not be used. Examples of sulfur containing materials that have beenfound to be suitable include a renewable liquid petrole
44、um material, a metal alloy, or a fused glass disk. The monitors countingrate, in combination with count time, shall be sufficient to give a relative counting error of less than 1 %. The counting rate forthe monitor sample is determined during calibration (see 9.4) and again at the time of analysis (
45、see 10.1). These counting ratesare used to calculate a drift correction factor (see 11.1).7.3.1 Drift correction is usually implemented automatically in software, although the calculation can readily be done manually.For X-ray instruments that are highly stable, the magnitude of the drift correction
46、 factor may not differ significantly from unity.7.4 Polysulfide Oil, generally nonyl polysulfides containing a known percentage of sulfur diluted in a hydrocarbon matrix.(WarningMay cause allergic skin reactions.)NOTE 6Polysulfide oils are high molecular weight oils that contain high concentrations
47、of sulfur, as high as 50 weight percent.%. They exhibitexcellent physical properties such as low viscosity, low volatility, and durable shelf life while being completely miscible in white oil. Polysulfide oils arereadily available commercially. The sulfur content of the polysulfide oil concentrate i
48、s determined via mass dilution in sulfur-free white oil followed bya direct comparison analysis against NIST (or other primary standards body) reference materials.7.5 Mineral Oil, White (MOW), ACS Reagent Grade containing less than 2 mg/kg sulfur or other suitable base materialcontaining less than 2
49、 mg/kg sulfur. When low level (1KW source) instruments are also included.14.2 BiasThe interlaboratory study6 included ten NIST standard reference materials (SRMs).(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 for C/H ratio. The white oil was assumed to have a C/H mass ratio of5.698 (C22H46).14.2.1 The variation in relative sulfur sensitivity as a function of C/H mass ratio is shown graphically in Fig.
