1、Designation: D5185 131Standard Test Method forMultielement Determination of Used and Unused LubricatingOils and Base Oils by Inductively Coupled Plasma AtomicEmission Spectrometry (ICP-AES)1This standard is issued under the fixed designation D5185; the number immediately following the designation in
2、dicates 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 revision or reapproval.This standard has been approved for use by agencies
3、of the U.S. Department of Defense.1NOTETable 4 was editorially corrected in April 2014.INTRODUCTIONCosts associated with maintenance due to engine and machine wear can be significant. Therefore,diagnostic methods for determining the condition of engines and other machinery can be important.This test
4、 method is intended to quantify, for the purpose of equipment monitoring, the concentrationof metals in used lubricating oils. Although the precision statement was determined by analyzing avariety of used oils this test method can, in principle, be used for the analysis of unused oils to providemore
5、 complete elemental composition data than Test Methods D4628, D4927,orD4951.1. Scope*1.1 This test method covers the determination of additiveelements, wear metals, and contaminants in used and unusedlubricating oils and base oils by inductively coupled plasmaatomic emission spectrometry (ICP-AES).
6、The specific ele-ments are listed in Table 1.1.2 This test method covers the determination of selectedelements, listed in Table 1, in re-refined and virgin base oils.1.3 For analysis of any element using wavelengths below190 nm, a vacuum or inert-gas optical path is required. Thedetermination of sod
7、ium and potassium is not possible on someinstruments having a limited spectral range.1.4 This test method uses oil-soluble metals for calibrationand does not purport to quantitatively determine insolubleparticulates. Analytical results are particle size dependent, andlow results are obtained for par
8、ticles larger than a fewmicrometers.21.5 Elements present at concentrations above the upper limitof the calibration curves can be determined with additional,appropriate dilutions and with no degradation of precision.1.6 For elements other than calcium, sulfur, and zinc, thelow limits listed in Table
9、 2 and Table 3 were estimated to be tentimes the repeatability standard deviation. For calcium, sulfur,and zinc, the low limits represent the lowest concentrationstested in the interlaboratory study.1.7 The values stated in SI units are to be regarded asstandard. No other units of measurement are in
10、cluded in thisstandard.1.8 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior
11、 to use. Specific warningstatements are given in 6.1, 8.2, and 8.4.2. Referenced Documents2.1 ASTM Standards:3C1109 Practice for Analysis of Aqueous Leachates fromNuclear Waste Materials Using Inductively CoupledPlasma-Atomic Emission SpectroscopyD1552 Test Method for Sulfur in Petroleum Products (H
12、igh-Temperature Method)D4057 Practice for Manual Sampling of Petroleum andPetroleum Products1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current editio
13、n approved Sept. 15, 2013. Published September 2013. Originallyapproved in 1991. Last previous edition approved in 2009 as D5185 09. DOI:10.1520/D5185-13E01.2Eisentraut, K. J., Newman, R. W., Saba, C. S., Kauffman, R. E., and Rhine, W.E., Analytical Chemistry, Vol 56, 1984.3For referenced ASTM stand
14、ards, 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 Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM Interna
15、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D4307 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 SpectrometryD
16、4927 Test Methods 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 Spe
17、ctrometryD7260 Practice for Optimization, Calibration, and Valida-tion of Inductively Coupled Plasma-Atomic EmissionSpectrometry (ICP-AES) for Elemental Analysis of Petro-leum Products and LubricantsE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related Materials3. Terminolog
18、y3.1 Definitions:3.1.1 emission spectroscopyrefer to Terminology E135.3.2 Definitions of Terms Specific to This Standard:3.2.1 additive elementa constituent of a chemical com-pound that improves the performance of a lubricating oil.3.2.2 analytean element whose concentration is beingdetermined.3.2.3
19、 Babington-type nebulizera device that generates anaerosol by flowing a liquid over a surface that contains anorifice from which gas flows at a high velocity.3.2.4 calibrationthe process by which the relationshipbetween signal intensity and elemental concentration is deter-mined for a specific eleme
20、nt analysis.3.2.5 calibration curvethe plot of signal intensity versuselemental concentration using data obtained by making mea-surements with standards.3.2.6 contaminanta foreign substance, generallyundesirable, introduced into a lubricating oil.3.2.7 detection limitthe concentration of an analyte
21、thatresults in a signal intensity that is some multiple (typically two)times the standard deviation of the background intensity at themeasurement wavelength.3.2.8 inductively-coupled plasma (ICP)a high-temperature discharge generated by flowing an ionizable gasthrough a magnetic field induced by a l
22、oad coil that surroundsthe tubes carrying the gas.3.2.9 linear response rangethe elemental concentrationrange over which the calibration curve is a straight line, withinthe precision of the test method.TABLE 1 Elements Determined and Suggested WavelengthsAElement Wavelength, nmAluminum 308.22, 396.1
23、5, 309.27Barium 233.53, 455.40, 493.41Boron 249.77Calcium 315.89, 317.93, 364.44, 422.67Chromium 205.55, 267.72Copper 324.75Iron 259.94, 238.20Lead 220.35Magnesium 279.08, 279.55, 285.21Manganese 257.61, 293.31, 293.93Molybdenum 202.03, 281.62Nickel 231.60, 227.02, 221.65Phosphorus 177.51, 178.29, 2
24、13.62, 214.91, 253.40Potassium 766.49Sodium 589.59Silicon 288.16, 251.61Silver 328.07Sulfur 180.73, 182.04, 182.62Tin 189.99, 242.95Titanium 337.28, 350.50, 334.94Vanadium 292.40, 309.31, 310.23, 311.07Zinc 202.55, 206.20, 213.86, 334.58, 481.05AThese wavelengths are only suggested and do not repres
25、ent all possiblechoices.TABLE 2 RepeatabilityElement Range, mg/kg Repeatability, g/gAAluminum 640 0.71 X0.41Barium 0.54 0.24 X0.66Boron 430 0.26 XCalcium 409000 0.0020 X1.4Chromium 140 0.17 X0.75Copper 2160 0.12 X0.91Iron 2140 0.13 X0.80Lead 10160 1.6 X0.32Magnesium 51700 0.16 X0.86Manganese 5700 0.
26、010 X1.3Molybdenum 5200 0.29 X0.70Nickel 540 0.52 X0.49Phosphorus 101000 1.3 X0.58Potassium 401200 3.8 X0.33Silicon 850 1.3 X0.26Silver 0.550 0.15 X0.83Sodium 770 0.49 X0.66Sulfur 9006000 0.49 X0.81Tin 1040 2.4 X0.17Titanium 540 0.54 X0.37Vanadium 150 0.061 XZinc 601600 0.15 X0.88Awhere: X = mean co
27、ncentration, g/g.TABLE 3 ReproducibilityElement Range, mg/kg Reproducibility, g/gAAluminum 640 3.8 X0.26Barium 0.54 0.59 X0.92Boron 430 13 X0.01Calcium 409000 0.015 X1.3Chromium 140 0.81 X0.61Copper 2160 0.24 XIron 2140 0.52 X0.80Lead 10160 3.0 X0.36Magnesium 51700 0.72 X0.77Manganese 5700 0.13 X1.2
28、Molybdenum 5200 0.64 X0.71Nickel 540 1.5 X0.50Phosphorus 101000 4.3 X0.50Potassium 401200 6.6 X0.29Silicon 850 2.9 X0.39Silver 0.550 0.35 XSodium 770 1.1 X0.71Sulfur 9006000 1.2 X0.75Tin 1040 2.1 X0.62Titanium 540 2.5 X0.47Vanadium 150 0.28 X1.1Zinc 601600 0.083 X1.1Awhere: X = mean concentration, g
29、/g.D5185 13123.2.10 profilinga technique that determines the wave-length for which the signal intensity measured for a particularanalyte is a maximum.3.2.11 radio frequency (RF)the range of frequencies be-tween the audio and infrared ranges (3 kHz to 300 GHz).3.2.12 wear metalan element introduced i
30、nto the oil bywear of oil-wetted parts.4. Summary of Test Method4.1 Aweighed portion of a thoroughly homogenized used orunused lubricating oil, or base oil, is diluted tenfold by weightwith mixed xylenes or other suitable solvent. Standards areprepared in the same manner. A mandatory internal standa
31、rd isadded to the solutions to compensate for variations in testspecimen introduction efficiency. The solutions are introducedto the ICP instrument by free aspiration or an optionalperistaltic pump. By comparing emission intensities of ele-ments in the test specimen with emission intensities measure
32、dwith the standards, the concentrations of elements in the testspecimen are calculable.4.2 Standard operating parameters and other considerationsto be considered in using ICP-AES technique are given inPractice D72605. Significance and Use5.1 This test method covers the rapid determination of 22eleme
33、nts in used and unused lubricating oils and base oils, andit provides rapid screening of used oils for indications of wear.Test times approximate a few minutes per test specimen, anddetectability for most elements is in the low mg/kg range. Inaddition, this test method covers a wide variety of metal
34、s invirgin and re-refined base oils. Twenty-two elements can bedetermined rapidly, with test times approximating severalminutes per test specimen.5.2 When the predominant source of additive elements inused lubricating oils is the additive package, significant differ-ences between the concentrations
35、of the additive elements andtheir respective specifications can indicate that the incorrect oilis being used. The concentrations of wear metals can beindicative of abnormal wear if there are baseline concentrationdata for comparison. A marked increase in boron, sodium, orpotassium levels can be indi
36、cative of contamination as a resultof coolant leakage in the equipment. This test method can beused to monitor equipment condition and define when correc-tive actions are needed.5.2.1 The significance of metal analysis in used lubricatingoils is tabulated in Table 4.5.3 The concentrations of metals
37、in re-refined base oils canbe indicative of the efficiency of the re-refining process. Thistest method can be used to determine if the base oil meetsspecifications with respect to metal content.6. Interferences6.1 SpectralCheck all spectral interferences expectedfrom the elements listed in Table 1.
38、Follow the manufacturersoperating guide to develop and apply correction factors tocompensate for the interferences. To apply interferencecorrections, all concentrations must be within the previouslyestablished linear response range of each element listed inTable 1.(WarningCorrect profiling is import
39、ant to revealspectral interferences from high concentrations of additiveelements on the spectral lines used for determining wearmetals.)6.1.1 Spectral interferences can usually be avoided byjudicious choice of analytical wavelengths. When spectralinterferences cannot be avoided, the necessary correc
40、tionsshould be made using the computer software supplied by theinstrument manufacturer or the empirical method describedbelow. Details of the empirical method are given in TestMethod C1109 and by Boumans.4This empirical correctionmethod cannot be used with scanning spectrometer systemswhen both the
41、analytical and interfering lines cannot be locatedprecisely and reproducibly. With any instrument, the analyst4Boumans, P. W. J. M., “Corrections for Spectral Interferences in OpticalEmission Spectrometry with Special Reference to the RF Inductively CoupledPlasma,” Spectrochimica Acta, 1976, Vol 31B
42、, pp. 147152.TABLE 4 Wear Metals (Elements) in Used Lubricating OilsElements Wear IndicationAluminum Piston and bearings wear, push rods, air cooler, pump hosings, oil pumps, gear castings, box castingsAntimony Crankshaft and camshaft bearingsBoron Coolant leakage in systemCadmium BearingsChromium R
43、ing wear, cooling system leakage, chromium-plated parts in aircraft engines, cylinder liners, seal ringsCopper Wear in bushings, injector shields, coolant core tubes, thrust washers, valve guides, connecting rods, piston rings, bearings, sleeves,bearing cagesIron Wear from engine block, cylinder, ge
44、ars, cylinder liners, valve guides, wrist pins, rings, camshaft, oil pump, crankshaft, ball and rollerbearings, rustLead Bearings, fuel blowby, thrust bearings, bearing cages, bearing retainersMagnesium Cylinder liner, gear box housings in aircraft enginesMolybdenum Wear in bearing alloys and in oil
45、 coolers; various molybdenum-alloyed components in aircraft engines, piston ringsNickel Bearings, valves, gear platingsSilicon Dirt intrusion from improper air cleaner, seal materialsSilver Wrist pin bearings in railroad and auto engines, silver plotted spline lubricating pumpSodium Antifreeze leaka
46、geTin Bearings and coatings of connecting rods and iron pistonsTitanium Various titanium-alloyed components in aircraft enginesTungsten BearingsZinc Neoprene seals, galvanized pipingEditorially corrected.D5185 1313must always be alert to the possible presence of unexpectedelements producing interfer
47、ing spectral lines.6.1.2 The empirical method of spectral interference correc-tion uses interference correction factors. These factors aredetermined by analyzing the single-element, high-purity solu-tions under conditions matching as closely as possible thoseused for test specimen analysis. Unless p
48、lasma conditions canbe accurately reproduced from day to day, or for longerperiods, interference correction factors found to affect theresults significantly must be redetermined each time specimensare analyzed.6.1.3 Interference correction factors, Kia, are defined asfollows: For analyte a, we have:
49、Ca 5 Ia/Ha (1)where:Ca = concentration of analyte a,Ia = net line intensity (that is, background corrected) ofanalyte a, andHa = sensitivity.6.1.3.1 Similarly, for an interferent i at the same wave-length:Ci 5 Ii/Hi (2)where:Ii = contribution from the peak or wing of the interferent lineto the peak intensity of the analyte a.6.1.3.2 The correction factor, Kia is defined as:Kia 5 Hi/Ha 5 Ii/Ci 3Ha! (3)6.1.3.3 Analysis of high-purity stock solutions with a cali-brated instrument gives Ii/Ha, the concentration
