1、Designation: D 5185 05An American National StandardStandard Test Method forDetermination of Additive Elements, Wear Metals, andContaminants in Used Lubricating Oils and Determination ofSelected Elements in Base Oils by Inductively CoupledPlasma Atomic Emission Spectrometry (ICP-AES)1This standard is
2、 issued under the fixed designation D 5185; 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 editorial c
3、hange since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.INTRODUCTIONCosts associated with maintenance due to engine and machine wear can be significant. Therefore,diagnostic methods for determining the condition of engines and othe
4、r machinery can be important.This test 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
5、analysis of unused oils to providemore complete elemental composition data than Test Methods D 4628, D 4927,orD 4951.1. Scope*1.1 This test method covers the determination of additiveelements, wear metals, and contaminants in used lubricatingoils by inductively coupled plasma atomic emission spectro
6、m-etry (ICP-AES). The specific elements 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. Thedet
7、ermination of sodium 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
8、 obtained for particles 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 limit
9、s listed in Table 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 as thestandard. The values give
10、n in parentheses are for informationonly.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
11、 limitations prior to use. Specific warningstatements are given in 6.1, 8.2, and 8.4.2. Referenced Documents2.1 ASTM Standards:3C 1109 Test Method for Analysis of Aqueous Leachatesfrom Nuclear Waste Materials Using Inductively CoupledPlasma-Atomic Emission SpectrometryD 1552 Test Method for Sulfur i
12、n Petroleum Products(High-Temperature Method)D 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD 4628 Test Method for Analysis of Barium, Calcium,1This test method is under the jurisdiction of ASTM Com
13、mittee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved Nov. 1, 2005. Published November 2005. Originallyapproved in 1991. Last previous edition approved in 2002 as D 518502e2.2Eisentraut, K. J., Newman, R.
14、W., Saba, C. S., Kauffman, R. E., and Rhine, W.E., Analytical Chemistry, Vol 56, 1984.3For 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 Document Summary
15、 page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Magnesium, and Zinc in Unused Lubricating Oils byAtomic Absorption SpectrometryD 4927 Test Met
16、hods 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 PlasmaAtomic Emission Spectrometr
17、yE 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related Materials3. Terminology3.1 Definitions:3.1.1 emission spectroscopyrefer to Terminology E 135.3.2 Definitions of Terms Specific to This Standard:3.2.1 additive elementa constituent of a chemical com-pound that improves t
18、he performance of a lubricating oil.3.2.2 analytean element whose concentration is beingdetermined.3.2.3 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
19、the relationshipbetween signal intensity and elemental concentration is deter-mined for a specific element 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, gener
20、ally undesir-able, introduced into a lubricating oil.3.2.7 detection limitthe concentration of an analyte 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
21、)a high-temperature discharge generated by flowing an ionizable gasthrough a magnetic field induced by a load 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
22、 method.3.2.10 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 into t
23、he oil bywear of oil-wetted parts.4. Summary of Test Method4.1 A weighed portion of a thoroughly homogenized usedoil is diluted tenfold by weight with mixed xylenes or otherTABLE 1 Elements Determined and Suggested WavelengthsAElement Wavelength, nmAluminum 308.22, 396.15, 309.27Barium 233.53, 455.4
24、0, 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, 213.62, 214.91, 253.40Potassiu
25、m 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 represent all possiblechoices.TABLE
26、 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 0.010 X1.3Molybdenum 5200 0.29
27、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 concentration, g/g.TABLE 3 Repr
28、oducibilityElement 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 X1.2Molybdenum 5200 0.64 X0.71Nic
29、kel 540 1.5 X0.50Phosphorus 101000 4.3 X0.50Potassium 401200 6.6 X0.29Silicon 850 2.9 X0.39Silver 0.5500.35 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/g.D5185052suitable solvent. S
30、tandards are prepared in the same manner.An optional internal standard can be added to the solutions tocompensate for variations in test specimen introduction effi-ciency. The solutions are introduced to the ICP instrument byfree aspiration or an optional peristaltic pump. By comparingemission inten
31、sities of elements in the test specimen withemission intensities measured with the standards, the concen-trations of elements in the test specimen are calculable.5. Significance and Use5.1 This test method covers the rapid determination of 22elements in used lubricating oils and in base oils, and it
32、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 metals invirgin and re-refined base oils. Twenty-two elements can
33、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 of the additive elements andtheir respective specifications c
34、an 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 indicative of contamination as a resultof coolant leakage in the
35、equipment. This test method can beused to monitor equipment condition and define when correc-tive actions are needed.5.3 The concentrations of metals 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 meetss
36、pecifications with respect to metal content.6. Interferences6.1 SpectralCheck all spectral interferences expectedfrom the elements listed in Table 1. Follow the manufacturersoperating guide to develop and apply correction factors tocompensate for the interferences. To apply interference correc-tions
37、, all concentrations must be within the previously estab-lished linear response range of each element listed in Table1.(WarningCorrect profiling is important to reveal spectralinterferences from high concentrations of additive elements onthe spectral lines used for determining wear metals.)6.1.1 Spe
38、ctral interferences can usually be avoided byjudicious choice of analytical wavelengths. When spectralinterferences cannot be avoided, the necessary correctionsshould be made using the computer software supplied by theinstrument manufacturer or the empirical method describedbelow. Details of the emp
39、irical method are given in TestMethod C 1109 and by Boumans.4This empirical correctionmethod cannot be used with scanning spectrometer systemswhen both the analytical and interfering lines cannot be locatedprecisely and reproducibly. With any instrument, the analystmust always be alert to the possib
40、le presence of unexpectedelements producing interfering 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 pos
41、sible thoseused for test specimen analysis. Unless plasma 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,
42、 Kia, are defined asfollows: For analyte a, we have: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
43、the peak or wing of the interferentline to 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 3 Ha! (3)6.1.3.3 Analysis of high-purity stock solutions with a cali-brated instrument gives Ii/Ha, the concentration error thatresults when analyzing a
44、 solution containing an interferent ofconcentration Ci. Dividing by Ci gives the dimensionlesscorrection factor Kia. To apply these correction factors:Ca, apparent 5 Ia 1 Ii!/Ha (4)Ca, apparent 5 Ca 1 Ii/Ha (5)Ca 5 Ca, apparent 2 Ii/Ha (6)Ca 5 Ca, apparent 2 Kia * Ci (7)and, for more than one interf
45、erent:Ca 5 Ca, apparent 2 K1a 3 C1 2 K2a 3 C2 2 . (8)6.1.4 Interference correction factors can be negative ifoff-peak background correction is employed for element i.Anegative Kia can result when an interfering line is encounteredat the background correction wavelength rather than at the peakwavelen
46、gth.6.2 Viscosity EffectsDifferences in the viscosities of testspecimen solutions and standard solutions can cause differ-ences in the uptake rates. These differences can adversely affectthe accuracy of the analysis. The effects can be reduced byusing a peristaltic pump to deliver solutions to the n
47、ebulizer orby the use of internal standardization, or both. When severeviscosity effects are encountered, dilute the test specimen andstandard twenty-fold rather than tenfold while maintaining thesame concentration of the internal standard.4Boumans, P. W. J. M., “Corrections for Spectral Interferenc
48、es in OpticalEmission Spectrometry with Special Reference to the RF Inductively CoupledPlasma,” Spectrochimica Acta, 1976, Vol 31B, pp. 147152.D51850536.3 ParticulatesParticulates can plug the nebulizerthereby causing low results. Use of a Babington type high-solids nebulizer helps to minimize this
49、effect. Also, thespecimen introduction system can limit the transport of par-ticulates, and the plasma can incompletely atomize particu-lates, thereby causing low results.7. Apparatus7.1 Balance, top loading, with automatic tare, capable ofweighing to 0.001 g, capacity of 150 g.7.2 Inductively-Coupled Plasma Atomic EmissionSpectrometerEither a sequential or simultaneous spectrom-eter is suitable, if equipped with a quartz ICP torch and RFgenerator to form and sustain the plasma. Suggested wave-lengths for the dete
