Multiphoton ionization/mass spectrometry of polybrominated diphenyl ethers

摘要

Gaschromatographycombinedwithmultiphotonionization/time-of-flightmassspectrometry(GC/MPI/TOF-MS)usingultravioletpicosecondandfemtosecondlaserswasemployedtoquantitativelyanalyzeaseriesofpolybrominateddiphenylethers(PBDEs).CongenersfrommonoBDEtotetraBDEswereanalyzedusingapicosecondlaseremittingat266nm.InordertoenhancetheefficiencyofionizationforhighlybrominatedDEsviatripletlevels,adifferentlaseremittingat213nmwasused.Itwas,however,difficulttoquantifysuchcongeners,evenatthiswavelength.ThisunexpectedresultcanbeexplainedbythephotodecompositionofPBDEsfromthetripletlevels.Ontheotherhand,allcongenersfrommonoBDEtodecaBDEweredetectedwhenafemtosecondlaseremittingat267nmwasemployed.Interestingly,theisomershavingasmallernumberofBratomsatthemeta-positionsweremoreefficientlyionized,andprovidedlowervaluesofdetectionlimit...