1、Designation: D 6443 04An American National StandardStandard Test Method forDetermination of Calcium, Chlorine, Copper, Magnesium,Phosphorus, Sulfur, and Zinc in Unused Lubricating Oilsand Additives by Wavelength Dispersive X-ray FluorescenceSpectrometry (Mathematical Correction Procedure)1This stand
2、ard is issued under the fixed designation D 6443; the number 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 (e) indicates an edito
3、rial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of calcium,chlorine, copper, magnesium, phosphorus, sulfur, and zinc inunused lubricating oils, additives, and additive packages bywavelength dispersive X-ray fluorescence spectrometry. Ma-trix e
4、ffects are handled with mathematical corrections.1.2 For each element, the upper limit of the concentrationrange covered by this test method is defined by the highestconcentration listed in Table 1. Samples containing higherconcentrations can be analyzed following dilution.1.3 For each element, the
5、lower limit of the concentrationrange covered by this test method can be estimated by the limitof detection (LOD)2(see also 40 CFR 136 Appendix B) orlimit of quantification (LOQ),2both of which can be estimatedfrom Sr, the repeatability standard deviation. LOD and LOQvalues, determined from results
6、obtained in the interlaboratorystudy on precision, are listed in Table 2.1.3.1 LOD and LOQ are not intrinsic constants of this testmethod. LOD and LOQ depend upon the precision attainableby a laboratory when using this test method.1.4 This test method uses regression software to determinecalibration
7、 parameters, which can include influence coeffi-cients (that is, interelement effect coefficients) (Guide E 1361),herein referenced as alphas. Alphas can also be determinedfrom theory using relevant software.1.5 Setup of this test method is intended for persons trainedin the practice of X-ray spectr
8、ometry. Following setup, this testmethod can be used routinely.1.6 The values stated in either SI units or angstrom units areto be regarded separately as standard.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
9、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:3D 1552 Test Method for Sulfur in Petroleum Products(High-Temperature Method)D 4057 Practice for Manual Sampli
10、ng of Petroleum andPetroleum ProductsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD 4628 Test Method for Analysis of Barium, Calcium,Magnesium, and Zinc in Unused Lubricating Oils byAtomic Abso
11、rption SpectrometryD 4927 Test Methods for Elemental Analysis of Lubricantand Additive ComponentsBarium, Calcium, Phospho-rus, Sulfur, and Zinc by Wavelength-Dispersive X-RayFluorescence SpectroscopyD 4951 Test Method for Determination of Additive Ele-ments in Lubricating Oils by Inductively Coupled
12、 PlasmaAtomic Emission Spectrometry1This 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 approved Nov. 1, 2004. Published November 2004. Originallyapproved in
13、1999. Last previous edition approved in 1999 as D 644399.2Analytical Chemistry, Vol 55, pp. 2210-2218.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards
14、Document Summary page onthe ASTM website.TABLE 1 Calibration Standard Compositions, Concentrations inMass %Std. No. Ca Cl Cu Mg P S Zn1 0.02 0.02 0.01 0.20 0.25 1.00 0.022 0.02 0.02 0.05 0.20 0.02 0.02 0.253 0.02 0.20 0.01 0.05 0.25 0.02 0.254 0.02 0.20 0.05 0.05 0.02 1.00 0.025 0.40 0.02 0.01 0.05
15、0.02 1.00 0.256 0.40 0.02 0.05 0.05 0.25 0.02 0.027 0.40 0.20 0.01 0.20 0.02 0.02 0.028 0.40 0.20 0.05 0.20 0.25 1.00 0.259 0.20 0.10 0.03 0.10 0.10 0.50 0.1010 0001*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
16、t Conshohocken, PA 19428-2959, United States.D 5185 Test Method for Determination of Additive Ele-ments, Wear Metals, and Contaminants in Used Lubricat-ing Oils and Determination of Selected Elements in BaseOils by Inductively Coupled Plasma Atomic EmissionSpectrometry (ICP-AES)D 6299 Practice for A
17、pplying Statistical Quality AssuranceTechniques to Evaluate Analytical Measurement SystemPerformanceE 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 1361 Guide for Correction of Interelement Effects inX-Ray Spectrometric Analysis2.2 Government Stan
18、dard:440 CFR, 136 Appendix B, Definition and Procedure for theDetermination of the Method Detection LimitRevision1.11, pp. 265-2673. Summary of Test Method3.1 The X-ray fluorescence spectrometer is initially cali-brated by the following procedure. For each element, the slopeand intercept of the cali
19、bration curve are determined byregressing concentration data and intensities measured on a setof physical standards. Empirical alphas can also be determinedby regression when the appropriate set of physical standards isused for calibration. Theoretical alphas, calculated with specialsoftware, can al
20、so be used. In addition, a combination oftheoretical and empirical alphas can be used.3.2 Asample is placed in the X-ray beam, and the intensitiesof the appropriate fluorescence lines are measured. A similarmeasurement is made at a wavelength offset from eachfluorescence line in order to obtain a ba
21、ckground correction.Enhancement or absorption of the X-ray fluorescence of ananalyte by an interfering element in the sample can occur, andthese effects can be handled in the data reduction by imple-mentation of alphas. Concentrations of the analytes are deter-mined by comparison of net signals agai
22、nst calibration curves,which include influence coefficients (that is, alphas) calculatedfrom theory, empirical data, or a combination of theory andempirical data.4. Significance and Use4.1 Lubricating oils can be formulated with additives, whichcan act as detergents, anti-oxidants, anti-wear agents,
23、 and soforth. Some additives can contain one or more of calcium,copper, magnesium, phosphorus, sulfur, and zinc. This testmethod can be used to determine if the oils, additives, andadditive packages meet specification with respect to content ofthese elements.4.2 This test method can also be used to
24、determine iflubricating oils, additives, and additive packages meet specifi-cation with respect to chlorine concentration. In this context,specification can refer to contamination.4.3 This test method is not intended for use on samples thatcontain some component that significantly interferes with th
25、eanalysis of the elements specified in the scope.4.4 This test method can complement other test methods forlube oils and additives, including Test Methods D 4628,D 4927, D 4951, and D 5185.5. Interferences5.1 The additive elements can affect the magnitudes of themeasured intensities for each analyte
26、. In general, theX-radiation emitted by each analyte can be absorbed by theother elements.Also, the X-radiation emitted by an analyte canbe enhanced by some other component. The magnitudes of theabsorption and enhancement effects can be significant. How-ever, implementation of accurately determined
27、alphas in the setof calibration parameters can satisfactorily correct for absorp-tion and enhancement effects, thereby making this test methodquantitative.5.2 Molybdenum lines can spectrally overlap lines of mag-nesium, phosphorus, sulfur, and chlorine. Lead lines canspectrally overlap sulfur. Thus,
28、 this test method cannot beapplied if molybdenum or lead are present at significantconcentrations and if accurate overlap corrections cannot bemade.5.3 When a large d-spacing diffraction structure containingsilicon is used as the analyzing crystal, corrections for thefluorescence of silicon may be n
29、eeded. Calcium X rays fromsample specimens cause silicon to fluoresce. This siliconradiation contributes to fluctuations in the background formagnesium measurements. If the effect is significant, thisinterference may be treated as a line overlap due to calcium.6. Apparatus6.1 X-ray Spectrometer, equ
30、ipped for detection of softX-ray radiation in the range from 1 to 10 angstroms. Foroptimum sensitivity, the spectrometer is equipped with thefollowing:6.1.1 X-ray Tube Source, with chromium, rhodium, orscandium target. Scandium can be advantageous for sensitivityenhancement of the low atomic number
31、analytes. Other targetsmay also be employed. Avoid spectral interferences from tubelines on the analyte lines.6.1.2 Helium, purgeable optical path.6.1.3 Interchangeable Analyzer Crystals, germanium,lithium fluoride (LiF200), graphite, pentaerythritol (PE), or a 50angstrom diffraction structure, or a
32、 combination thereof. Othersuitable crystals can be used.6.1.4 Pulse-Height Analyzer.6.1.5 Detector, gas flow proportional, or tandem gas flowproportional and scintillation counter.NOTE 1A gas sealed proportional counter was used in the interlabo-ratory study on precision and was found to be satisfa
33、ctory.6.2 Mixing Device Such as a Shaker, Ultrasonic Bath, orVortex Mixer, capable of handling from 30-mL to 1-L bottles.4Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.TABLE 2 Estimated LOD and LOQ, Units are M
34、ass %Ca Cl Cu Mg P ZnLOD 0.0002 0.0004 0.0002 0.0039 0.0006 0.0002LOQ 0.0008 0.0015 0.0007 0.0130 0.0020 0.0007D64430426.3 X-ray Disposable Plastic Cells, with suitable film win-dow. Suitable films can include polyester, polypropylene, orpolyimide. A film thickness of 4 m is preferred. Avoid usingfi
35、lm that contains any of the analytes.7. Reagents and Materials7.1 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 the American Chemical Society, wh
36、eresuch specifications are available.5Other grades can 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 Helium, preferably ultrahigh purity (at least 99.95 %),for optical path of spectrome
37、ter.7.3 P-10 Ionization Gas, 90 volume % argon and 10 volume% methane for the flow proportional counter.NOTE 2P-10 gas was used in the interlaboratory study on precision.Other satisfactory gases or gas mixtures can be applicable.7.4 Dilution Solvent, a hydrocarbon solvent, which does notcontain a de
38、tectable amount of any analyte. U.S.P. white(mineral) oil has been found to be satisfactory.7.5 Calibration Standard Materials:7.5.1 Concentrated Solutions of Oil-soluble Compounds,each containing one of the following: calcium, copper, mag-nesium, phosphorus, or zinc.7.5.1.1 Some commercially availa
39、ble oil-soluble standardmaterials are prepared from sulfonates and therefore containsulfur. To use these materials for preparation of the calibrationstandard blends, it is necessary to know their sulfur concen-trations. Test Method D 1552, or other appropriate methods,can be used to determine sulfur
40、 content.7.5.1.2 Secondary standards, such as those prepared frompetroleum additives, for example, can also be used if their usedoes not affect the analytical results by more than the repeat-ability of this test method.7.5.2 Di-n-butyl Sulfide, a high-purity standard with a cer-tified analysis for t
41、otal sulfur content.NOTE 3Di-n-butyl sulfide is flammable and toxic.7.5.3 Oil-soluble Chlorine-containing Compound, a highpurity standard with a certified analysis for total chlorinecontent.7.5.4 Stabilizers, Stabilizers can be used to ensure unifor-mity of the calibration standard blends. Use stabi
42、lizers that donot contain a detectable amount of any analyte.8. Sampling and Sample Handling8.1 Take samples in accordance with the instructions inPractice D 4057 or D 4177, when applicable.8.2 Mix well samples and calibration standard blends beforeintroduction into the X-ray instrument.9. Preparati
43、on of Calibration Standards9.1 Prepare calibration standard blends by accurate dilutionof the oil-soluble standard solutions with the dilution solvent.These blends (Practice D 4307), with accurately known analyteconcentrations, shall approximate the nominal values listed inTable 1.9.1.1 When empiric
44、al alphas are determined by regression,prepare and measure all standard blends listed in Table 1.9.1.2 When theoretical alphas are used, a subset of thestandard blends (for example, standards 2, 6, 8, and 10) can besatisfactory.9.2 Drift Correction Monitors (Optional)The use of driftcorrection monit
45、ors for determination and correction of instru-ment drift can be advantageous. Monitors are stable, solid disksor pellets containing all elements covered by this test method.Two disks are preferred to correct for both sensitivity and baseline drifts. The high-concentration drift monitor provideshigh
46、-count rates, so that for each analyte, counting error is lessthan 0.25 % relative. The low-concentration drift monitorprovides low-count rates, so that for each element, count rate issimilar to that obtained with the calibration blank, or zeromass % standard.10. Calibration10.1 For the Ka-spectral
47、line for each analyte, assemble achannel per operating instructions of the X-ray instrument.Suggested, approximate instrument settings are listed in Table5. Actual settings can be instrument dependent; hence, theinformation in Table 5 is for guidance only.10.2 For correct operation of the X-ray inst
48、rument, as-semble the required measurement program, calculation pro-gram, and monitor program (when drift correction monitors areimplemented), as appropriate.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reag
49、ents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 3 Calculated Repeatability (r) and Reproducibility (R) for Oils, Units are Mass %Ca Cl Cu Mg P S ZnConcn r R r R r R r R r R r R r R0.0010 0.0003 0.0020 0.0003 0.0020 0.0002 0.0009 0.0002 0.0007 0.0001 0.00050.0030 0.0004 0.0029 0.0004 0.0021 0.0003 0.0012 0.0025 0.0081 0.0004 0.0016 0.0002 0.00120.0100 0.0007 0.0049 0.0007 0.0025 0.00
