ASTM_D_3239_-_91_2011.pdf

Designation:D323991(Reapproved 2011)Standard Test Method forAromatic Types Analysis of Gas-Oil Aromatic Fractions byHigh Ionizing Voltage Mass Spectrometry1This standard is issued under the fixed designation D3239;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 revision or reapproval.1.Scope1.1 This test method2covers the determination by highionizing voltage,low resolution mass spectrometry of 18aromatic hydrocarbon types and 3 aromatic thiophenotypes instraight run aromatic petroleum fractions boiling within therange from 205 to 540C(400 to 1000F)(corrected toatmospheric pressure).Samples must be nonolefinic,mustcontain not more than 1 mass%of total sulfur,and mustcontain not more than 5%nonaromatic hydrocarbons.Com-position data are in volume percent.NOTE1Although names are given to 15 of the compound typesdetermined,the presence of other compound types of the same empiricalformulae is not excluded.All other compound types in the sample,unidentified by name or empirical formula,are lumped into six groups inaccordance with their respective homologous series.1.2 The values stated in acceptable SI units are to beregarded as the standard.The values given in parentheses areprovided for information purposes only.1.3 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 to use.2.Referenced Documents2.1 ASTM Standards:3D2549 Test Method for Separation of Representative Aro-matics and Nonaromatics Fractions of High-Boiling Oilsby Elution ChromatographyD2786 Test Method for Hydrocarbon Types Analysis ofGas-Oil Saturates Fractions by High Ionizing VoltageMass SpectrometryE137 Practice for Evaluation of Mass Spectrometers forQuantitative Analysis from a Batch Inlet(Withdrawn1992)43.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Characteristic Mass Summations Classes IVII:3.1.2 Class I:(785 78192110611201.to end,polyisotopic(1)191110511191.to end,monoisotopic3.1.3 Class II:(1045 1041118113211461.to end,polyisotopic(2)1117113111451.to end,monoisotopic3.1.4 Class III:(1295 1301144115811721.to end,polyisotopic(3)11291143115711711.to end,monoisotopic3.1.5 Class IV:(1285 1281142115611701.to end,polyisotopic(4)1141115511691.to end,monoisotopic3.1.6 Class V:(1545 1541168118211961.to end,polyisotopic(5)1167118111951.to end,monoisotopic3.1.7 Class VI:(1665 1661180119412081.to end,polyisotopic(6)1179119312071.to end,monoisotopic3.1.8 Class VII:1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricantsand is the direct responsibility of SubcommitteeD02.04.0M on Mass Spectroscopy.Current edition approved Oct.1,2011.Published October 2011.Originallyapproved in 1973.Last previous edition approved in 2006 as D3239 91(2006).DOI:10.1520/D3239-91R11.2Robinson,C.J.,and Cook,G.L.,Analytical Chemistry(ANCHA),Vol 41,1969,p.1548.3For 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 page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1(1785 1781192120612201.to end,polyisotopic(7)1191120512191.to end,monoisotopic3.1.9 Classes,Compound Types,Empirical FormulaeSeeTable 1.4.Summary of Test Method4.1 The relative abundance of seven classes(IVII)ofaromatics in petroleum aromatic fractions is determined bymass spectrometry using a summation of peaks most charac-teristic of each class.Calculations are carried out by the use ofa 7 by 7 inverted matrix derived from published spectra of purearomatic compounds.Each summation of peaks includes thepolyisotopic homologous series that contains molecular ionsand the monoisotopic homologous series one mass unit lessthan the molecular ion series.Using characteristic summationsfound in the monoisotopic molecular ion1 series of peaks,each class is further resolved to provide relative abundances ofthree compound types:nominal(Type 0),first overlap(Type1),and second overlap(Type 2).The aromatic fraction isobtained by liquid elution chromatography(see Test MethodD2549).NOTE2Monoisotopic peaks heights are obtained by correcting thepolyisotopic heights for naturally occurring heavy isotopes,assuming thatonly ions of CnH2n+2to CnH211are present.This is not strictly accuratefor aromatics,but the errors introduced by such assumption are trivial.5.Significance and Use5.1 Aknowledge of the hydrocarbon composition