1、Designation: D6443 04 (Reapproved 2010)Standard 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 standard is issue
2、d under the fixed designation D6443; 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 () indicates an editorial change si
3、nce the last revision or reapproval.1. Scope1.1 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 effects are hand
4、led 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 lower limit of
5、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 obtained in the
6、 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 parameters, wh
7、ich can include influence coeffi-cients (that is, interelement effect coefficients) (Guide E1361),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 spectrometry. Followin
8、g 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 user of this sta
9、ndard 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:3D1552 Test Method for Sulfur in Petroleum Products(High-Temperature Method)D4057 Practice for Manual Sampling of Petroleum an
10、dPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD4628 Test Method for Analysis of Barium, Calcium,Magnesium, and Zinc in Unused Lubricating Oils byAtomic Absorption SpectrometryD4
11、927 Test Methods for Elemental Analysis of Lubricantand Additive ComponentsBarium, Calcium, Phospho-rus, Sulfur, and Zinc by Wavelength-Dispersive X-RayFluorescence SpectroscopyD4951 Test Method for Determination of Additive Ele-ments in Lubricating Oils by Inductively Coupled PlasmaAtomic Emission
12、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 May 1, 2010. Published May 2010. Originallyapproved in 1999. Last previous edition a
13、pproved in 2004 as D644304. DOI:10.1520/D6443-04R10.2Analytical 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 Docum
14、ent 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 0.02
15、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 0001Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D5185 Test Method for Dete
16、rmination 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)D6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to E
17、valuate AnalyticalMeasurement System PerformanceE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE1361 Guide for Correction of Interelement Effects inX-Ray Spectrometric Analysis2.2 Government Standard:440 CFR, 136 Appendix B, Definition and Procedure
18、 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 calibration curve are determined byregressing concentratio
19、n 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 also be used. In addition, a combination oftheoretical a
20、nd 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 background correction.Enhancement or absorption of the X
21、-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 against calibration curves,which include influence coeffic
22、ients (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, and soforth. Some additives can contain one or more o
23、f 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 determine iflubricating oils, additives, and additive
24、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 theanalysis of the elements specified in the scope.4.4 T
25、his test method can complement other test methods forlube oils and additives, including Test Methods D4628, D4927,D4951, and D5185.5. Interferences5.1 The additive elements can affect the magnitudes of themeasured intensities for each analyte. In general, theX-radiation emitted by each analyte can b
26、e 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 alphas in the setof calibration parameters can satisfactor
27、ily 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, this test method cannot beapplied if molybdenum or lead a
28、re 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 needed. Calcium X rays fromsample specimens cause silicon t
29、o 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, equipped for detection of softX-ray radiation in the range fr
30、om 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 analytes. Other targetsmay also be employed. Avoid spectra
31、l 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 combination thereof. Othersuitable crystals can be used.6
32、.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 satisfactory.6.2 Mixing Device Such as a Shaker, Ultrasonic Bath,
33、 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 Mass %Ca Cl Cu Mg P ZnLOD 0.0002 0.0004 0.0002 0.0039 0.000
34、6 0.0002LOQ 0.0008 0.0015 0.0007 0.0130 0.0020 0.0007D6443 04 (2010)26.3 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 usingfilm that contains any of the analytes.7. Reagents a
35、nd 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, wheresuch specifications are available.5Other grades
36、 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 spectrometer.7.3 P-10 Ionization Gas, 90 volume % argon and
37、 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 detectable amount of any analyte. U.S.P. white(miner
38、al) 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 available oil-soluble standardmaterials are prepared fro
39、m 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 D1552, or other appropriate methods, canbe used to determine sulfur content.7.5.1.2 Secondary standards, such as those
40、 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 total sulfur content.NOTE 3Di-n-butyl sulfide is fla
41、mmable 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 stabilizers that donot contain a detectable amount of an
42、y analyte.8. Sampling and Sample Handling8.1 Take samples in accordance with the instructions inPractice D4057 or D4177, when applicable.8.2 Mix well samples and calibration standard blends beforeintroduction into the X-ray instrument.9. Preparation of Calibration Standards9.1 Prepare calibration st
43、andard blends by accurate dilutionof the oil-soluble standard solutions with the dilution solvent.These blends (Practice D4307), with accurately known analyteconcentrations, shall approximate the nominal values listed inTable 1.9.1.1 When empirical alphas are determined by regression,prepare and mea
44、sure 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 monitors for determination and correction of instru-ment dr
45、ift 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-count rates, so that for each analyte, counting error
46、 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 line for each analyte, assemble achannel per operating
47、 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 instrument, as-semble the required measurement program, ca
48、lculation pro-gram, and monitor program (when drift correction monitors areimplemented), as appropriate.10.3 When drift correction monitors are implemented, mea-sure monitor intensities for each analyte.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washingto
49、n, DC. For Suggestions on the testing of reagents 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 0.000
