5533r2010AmericanChemicalSocietypubs.acs.org/EFEnergyFuels2010,24,5533–5538:DOI:10.1021/ef1007352PublishedonWeb09/08/2010IdentificationofDihydroxyAromaticCompoundsinaLow-TemperaturePyrolysisCoalTarbyGasChromatography-MassSpectrometry(GC-MS)andFourierTransformIonCyclotronResonanceMassSpectrometry(FT-ICRMS)QuanShi,*,†YanYan,†XiaojiaoWu,†ShuyuanLi,*,†KengH.Chung,‡SuoqiZhao,†andChunmingXu††StateKeyLaboratoryofHeavyOilProcessing,ChinaUniversityofPetroleum,Beijing102200,China,and‡WellResources,Incorporated,Edmonton,AlbertaT6R1J8,CanadaReceivedJune12,2010.RevisedManuscriptReceivedAugust24,2010Dihydroxyaromaticsincoaltarundergorapidcouplingreactionswitheachotherandwithsomecoal-derivedspeciesduringcoalpyrolysisandliquefaction.However,onlylimitedinformationonthestructureofdihydroxyaromaticsisknown.Inthisstudy,Fouriertransformioncyclotronresonancemassspectrometry(FT-ICRMS)andgaschromatography-massspectrometry(GC-MS)wereusedtocharacterizethedihydroxyaromaticsinalow-temperaturepyrolyzedcoaltaranditsdistillateandresiduefractions.Negative-ionelectrosprayionization(ESI)FT-ICRMSspectraofcoal-tar-derivedsampleshadlowmolecularmassesandnarrowmassranges.Negative-ionESIisextremelyselectiveforthedihydroxyaromaticspresentincoaltar.TheO2classspecieshadthehighestionintensityamongthespeciesinthenegative-ionFT-ICRmassspectrumforeachsample.Dihydroxycompoundswithanaromaticcorestructureofbenzene,indan,biphenyl(and/oracenaphthene),andnaphthalenewereidentifiedinthedistillatefractions.Dihydroxycompoundsintheresiduefractionweredihydroxyfluorenesandphenan-threnes(and/oranthracenes).TheO2classspecieswithrelativelyhighmolecularmasseswerelikelydihydroxyacenaphthylenesand/orhydroxydibenzofuransbutcouldnotbedistinguishedfromeachotherbecausethesecompoundshavethesamemolecularmass.1.IntroductionThephysicalpropertiesandreactivityofcoalarekeyparametersfordevelopmentsincoaluseinliquefaction,gasification,andpyrolysis.Theseparametersareaffectedbytheoxygenatedcompounds,whicharethekeyspeciesfoundincoal.1,2Manyanalyticaltechniqueshavebeenusedtocharacterizethemolecularstructureandmassdistributionofcoalandcoal-derivedliquids.Themostcommonlyusedtechniqueismassspectrometry(MS)3,4incombinationwithtechniquessuchasgaschromatography(GC),5-8liquidchro-matography(LC),9-12andinjectionprobe.13Variousioniza-tiontechniqueshavealsobeenused,includingchemicalionization(CI),3,14,fieldionization(FI),9-11,3,15fielddesorp-tion(FD),3,15,16fastatombombardment(FAB),3,17laser*Towhomcorrespondenceshouldbeaddressed.Telephone:8610-8973-3738.Fax:8610-6972-4721.E-mail:sq@cup.edu.cn(Q.S.);syli@cup.edu.cn(S.L.).(1)Hodek,W.;Kirschstein,J.;vanHeek,K.-H.Reactionsofoxygencontainingstructuresincoalpyrolysis.Fuel1991,70(3),424–428.(2)McMillen,D.F.;Malhotra,R.;Chang,S.-J.;EstherNigenda,S.;St.John,G.A.Couplingpathwaysfordihydroxyaromaticsduringcoalpyrolysisandliquefaction.Fuel2004,83(11-12),1455–1467.(3)Herod,A.A.;Stokes,B.J.;Schulten,H.R.Coaltaranalysisbymassspectrometry;Acomparisonofmethods.Fuel1993,72(1),31–43.(4)Herod,A.A.;Millan,M.;Morgan,T.;Li,W.;Feng,J.;Kandiyoti,R.Positive-ionelectrosprayionisationmassspectrometryofacetone-andacetonitrile-solublefractionsofcoalderivedliquids.Eur.J.MassSpectrom.2005,11(4),429–442.(5)White,C.M.;Schweighardt,F.K.;Shultz,J.L.Combinedgaschromatographic-massspectrometricanalysesofnitrogenbasesinlightoilfromacoalliquefactionproduct.FuelProcess.Technol.1978,1(3),209–215.(6)Novotny,M.;Strand,J.W.;Smith,S.L.;Wiesler,D.;Schwende,F.J.Compositionalstudiesofcoaltarbycapillarygaschromatography/massspectrometry.Fuel1981,60(3),213–220.(7)Moeder,M.;Zimmer,D.;Stach,J.;Herzschuh,R.GC-MSandMS-MSinvestigationsofderivatizedhydroxyaromaticcompoundsfromcoal-derivedliquids.Fuel1989,68(11),1422–1428.(8)McClennen,W.H.;Meuzelaar,H.L.C.;Metcalf,G.S.;Hill,G.R.Characterizationofphenolsandindanolsincoal-derivedliquids:UseofCurie-pointvaporizationgaschromatography/massspectro-metry.Fuel1983,62(12),1422–1429.(9)Allen,T.W.;Hurtubise,R.J.;Silver,H.F.Comparisonofhydrocarboncompositionincomplexcoal-liquidsamplesbyliquidchromatographyandfield-ionizationmassspectroscopy.Anal.Chem.1985,57(3),666–671.(10)Boduszynski,M.M.;Hurtubise,R.J.;Allen,T.W.;Silver,H.F.Determinationofhydrocarboncompositioninhigh-boilingandnon-distillablecoalliquidsbyliquidchromatography/fieldionizationmassspectrometry.Anal.Chem.1983,55(2),232–241.(11)Boduszynski,M.M.;Hurtubise,R.J.;Allen,T.W.;Silver,H.F.Liquidchromatography/fieldionizationmassspectrometryintheanaly-sisofhigh-boilingandnondistillablecoalliquidsforhydrocarbons.Anal.Chem.1983,55(2),225–231.(12)Bonnett,R.;Burke,P.J.;Dewey,C.R.;Fairbrother,A.E.;Major,H.J.Metalloporphyrinsincoal5.Analysisofporphyrinsincoalextractsusingliquidchromatography-massspectrometry.Fuel1991,70(10),1227–1229.(13)Herod,A.A.;Kandiyoti,R.Fractionationbyplanarchroma-tographyofacoaltarpitchforcharacterisationbysize-exclusionchromatography,UVfluorescenceanddirect-probemassspectrometry.J.Chromatogr.,A1995,708(1),143–160.(14)Miller,D.J.;Hawthorne,S.B.Identificationofheteroaromaticcompoundsincoalliquef