1、Designation:D769116Standard Test Method forMultielement Analysis of Crude Oils Using InductivelyCoupled Plasma Atomic Emission Spectrometry(ICP-AES)1This standard is issued under the fixed designation D7691;the number immediately following the designation indicates the year oforiginal adoption or,in
2、 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.1.Scope*1.1 This test method covers the determination of severalelements(including iron,nickel,sulfu
3、r,and vanadium)occur-ring in crude oils.1.2 For analysis of any element using wavelengths below190 nm,a vacuum or inert gas optical path is required.1.3 Analysis for elements such as arsenic,selenium,orsulfur in whole crude oil may be difficult by this test methoddue to the presence of their volatil
4、e compounds of theseelements in crude oil;but this test method should work forresid samples.1.4 Because of the particulates present in crude oil samples,if they do not dissolve in the organic solvents used or if they donot get aspirated in the nebulizer,low elemental values mayresult,particularly fo
5、r iron and sodium.This can also occur ifthe elements are associated with water which can drop out ofthe solution when diluted with solvent.1.4.1 An alternative in such cases is using Test MethodD5708,Procedure B,which involves wet decomposition of theoil sample and measurement by ICP-AES for nickel,
6、vanadium,and iron,or Test Method D5863,Procedure A,which also uses wet acid decomposition and determinesvanadium,nickel,iron,and sodium using atomic absorptionspectrometry.1.4.2 From ASTM Interlaboratory Crosscheck Programs(ILCP)on crude oils data available so far,it is not clear thatorganic solvent
7、 dilution techniques would necessarily givelower results than those obtained using acid decompositiontechniques.21.4.3 It is also possible that,particularly in the case ofsilicon,low results may be obtained irrespective of whetherorganic dilution or acid decomposition is utilized.Silicones arepresen
8、t as oil field additives and can be lost in ashing.Silicatesshould be retained but unless hydrofluoric acid or alkali fusionis used for sample dissolution,they may not be accounted for.1.5 This test method uses oil-soluble metals for calibrationand does not purport to quantitatively determine insolu
9、bleparticulates.Analytical results are particle size dependent andlow results may be obtained for particles larger than a fewmicrometers.1.6 The precision in Section 18 defines the concentrationranges covered in the interlaboratory study.However,lowerand particularly higher concentrations can be det
10、ermined bythis test method.The low concentration limits are dependent onthe sensitivity of the ICP instrument and the dilution factorused.The high concentration limits are determined by theproduct of the maximum concentration defined by the calibra-tion curve and the sample dilution factor.1.7 Eleme
11、nts present at concentrations above the upper limitof the calibration curves can be determined with additionalappropriate dilutions and with no degradation of precision.1.8 As a generality based on this interlaboratory study(see18.1),the trace elements identifiable in crude oils can bedivided into t
12、hree categories:1.8.1 Element levels that are too low for valid detection byICP-AES and hence,cannot be determined:aluminum,barium,lead,magnesium,manganese,and silicon.1.8.2 Elements that are just at the detection levels of theICP-AES method and hence,cannot be determined with a greatdeal of confide
13、nce:boron,calcium,chromium,copper,molybdenum,phosphorus,potassium,sodium,and zinc.Per-haps the determination of these elements can be considered assemi-quantitative.1.8.3 Elements that are at higher levels of concentration andcan be determined with good precision:iron,nickel,sulfur,andvanadium.1.9 T
14、he detection limits for elements not determined by thistest method follow.This information should serve as anindication as to what elements are not present above thedetection limits typically obtainable by ICP-AES instruments.1This test method is under the jurisdiction of ASTM Committee D02 onPetrol
15、eum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved June 1,2016.Published June 2016.Originallyapproved in 2011.Last previous edition approved in 2011 as D7961 111.DOI:10.1520/D7691-16.2Nadkarni,R.A.,Hwang,J.D.
16、,andYoung,L.,“MultielementAnalysis of CrudeOils Using Inductively Coupled Plasma Atomic Emission Spectrometry,”J.ASTMInternational,Vol 8,No.10,2011,pp.103837.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Elementmg/kgAluminum1Barium0.2Boron1Calcium0.1Chromium0.1Copper0.1Lead1.4Magnesium1Manganese0.1Molybdenum0.2Phosphorous1Potassium0.5Silicon4Zinc0.51.10 This test metho
