1、Designation: D6443 14Standard 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 issued under the fixed
2、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 since the last revis
3、ion 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 effects are handled with mathemat
4、ical 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 the concentration
5、range 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 interlaboratorys
6、tudy 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, which can include i
7、nfluence 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. Following setup, this tes
8、tmethod 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 standard to establis
9、h 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 andPetroleum Produ
10、ctsD4177 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 SpectrometryD4927 Test Methods
11、 for Elemental Analysis of Lubricantand Additive ComponentsBarium, Calcium,Phosphorus, Sulfur, and Zinc by Wavelength-DispersiveX-Ray Fluorescence SpectroscopyD4951 Test Method for Determination of Additive Elementsin Lubricating Oils by Inductively Coupled PlasmaAtomic Emission SpectrometryD5185 Te
12、st Method for Multielement Determination ofUsed and Unused Lubricating Oils and Base Oils byInductively Coupled Plasma Atomic Emission Spectrom-etry (ICP-AES)D6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceE
13、29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current ed
14、ition approved Dec. 1, 2014. Published January 2015. Originallyapproved in 1999. Last previous edition approved in 2010 as D6443 04 (2010).DOI: 10.1520/D6443-14.2Analytical Chemistry, Vol 55, pp. 2210-2218.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
15、Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19
16、428-2959. United States1E1361 Guide for Correction of Interelement Effects inX-Ray Spectrometric Analysis2.2 Government Standard: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 fluores
17、cence spectrometer is initially cali-brated by the following procedure. For each element, the slopeand intercept of the calibration curve are determined byregressing concentration data and intensities measured on a setof physical standards. Empirical alphas can also be determinedby regression when t
18、he appropriate set of physical standards isused for calibration. Theoretical alphas, calculated with specialsoftware, can also 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 fluorescenc
19、e 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-ray fluorescence of ananalyte by an interfering element in the sample can occur, andthese effects can be handled in the d
20、ata reduction by imple-mentation of alphas. Concentrations of the analytes are deter-mined by comparison of net signals against calibration curves,which include influence coefficients (that is, alphas) calculatedfrom theory, empirical data, or a combination of theory andempirical data.4. Significanc
21、e 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 of calcium,copper, magnesium, phosphorus, sulfur, and zinc. This testmethod can be used to determine if the oils, additives
22、, andadditive packages meet specification with respect to content ofthese elements.4.2 Several additive elements and their compounds areadded to the lubricating oils to give beneficial performance(Table 3).4.3 This test method can also be used to determine iflubricating oils, additives, and additive
23、 packages meet specifi-cation with respect to chlorine concentration. In this context,specification can refer to contamination.4.4 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.4.5
24、This 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
25、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.However, implementation of accurately determined alphas inthe set of calibration parameters can satisfactori
26、ly correct forabsorption and enhancement effects, thereby making this testmethod quantitative.5.2 Molybdenum lines can spectrally overlap lines ofmagnesium, phosphorus, sulfur, and chlorine. Lead lines canspectrally overlap sulfur. Thus, this test method cannot beapplied if molybdenum or lead are pr
27、esent 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 to flu
28、oresce. 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 soft X-rayradiation in the range from 1
29、to 10 angstroms. For optimumsensitivity, the spectrometer is equipped with the following: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 spectral in
30、terferences 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.4Avai
31、lable from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.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
32、.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 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 000TABLE 2 Estimated LOD and LOQ, Units are Mass
33、 %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 0.0007D6443 1426.1.4 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 int
34、erlabo-ratory study on precision and was found to be satisfactory.6.2 Mixing Device Such as a Shaker, Ultrasonic Bath, orVortex Mixer, capable of handling from 30-mL to 1-L bottles.6.3 X-ray Disposable Plastic Cells, with suitable film win-dow. Suitable films can include polyester, polypropylene, or
35、polyimide. A film thickness of 4 m is preferred. Avoid usingfilm 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 Commit
36、tee onAnalytical Reagents of the American Chemical Society, wheresuch 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 ult
37、rahigh purity (at least 99.95 %),for optical path of spectrometer.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 Dilut
38、ion Solvent, a hydrocarbon solvent, which does notcontain a detectable 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
39、nesium, phosphorus, or zinc.7.5.1.1 Some commercially available 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 D1552, o
40、r other appropriate methods, canbe used to determine sulfur 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 Sulfi
41、de, a high-purity standard with a cer-tified analysis for total 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 ensur
42、e unifor-mity of the calibration standard blends. Use stabilizers that donot contain a detectable amount of any 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
43、beforeintroduction into the X-ray instrument.9. Preparation of Calibration Standards9.1 Prepare calibration standard blends by accurate dilutionof the oil-soluble standard solutions with the dilution solvent.These blends (Practice D4307), with accurately known analyteconcentrations, shall approximat
44、e the nominal values listed inTable 1.9.1.1 When empirical 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 Correc
45、tion Monitors (Optional)The use of driftcorrection monitors 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.5Reagent Chemicals, American Chemical Society Specifications, American
46、Chemical Society, Washington, 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),
47、Rockville,MD.TABLE 3 Lubricants and Additive MaterialsElement Compounds Purpose/ApplicationCalcium Sulfonates, phenates Detergent inhibitors, dispersantsChlorine Trace contaminants, chlorinated cleaning solvents Avoid servo-valve erosion, dewaxing compoundsCopper Copper dithiophosphates Anti-wear ag
48、ent, anti-oxidantMagnesium Sulfonates, phenates Detergent inhibitorsPhosphorus dithiophosphates, phosphates phosphites anti-rusting agents, extreme pressure additives, anti-wearSulfur Base oils, sulfonates, thiophosphates, polysulfidesand other sulfurized componentsDetergents, extreme pressure addit
49、ives, anti-wearZinc Dialkyldithiophosphates, dithiocarbamates,phenolates carboxylatesAnti-oxidant, corrosion inhibitors, antiwear additives, detergents, crankcaseoils, hypoid gear lubricants, aircraft piston engine oils, turbine oils, automatictransmission fluids, railroad diesel engine oils, brake lubricantsD6443 143Two 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 is lessthan 0.25 % relative. The low-concentration drift monitorprovides low-co
