title: Powerful GC-TOF-MS Techniques for Screening, Identification and Quantification of Halogenated Natural Products.
abstract: Comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC TOFMS) and gas chromatography/high-resolution time-of-flight mass spectrometry (GC-HRT) were used to detect and identify halogenated natural products (HNPs) in tissue homogenate, in this case brominated analytes present in a marine snail. Two classes of brominated anthropogenic compounds, polybrominated diphenyl ethers (PBDEs) and brominated dibenzofurans, were analyzed for comparison. Following conventional preparation, the sample was analyzed using GC×GC-TOF-MS. Isotope ratio scripts were used to compile a list of putatively brominated analytes from amongst the thousands of features resolved in the two-dimensional chromatogram. The structured nature of the chromatogram was exploited to propose identifications for several classes of brominated compounds, and include additional candidates that fell marginally outside the script tolerances. The sample was subsequently analyzed by GC-HRT. The high-resolution mass spectral data confirmed many formula assignments, facilitated confident assignment of an alternate formula when an original proposal did not hold, and enabled unknown identification. Identified HNPs include hydroxylated and methoxylated PBDE analogs, polybrominated dibenzo-p-dioxins (PBDDs) and hydroxyl-PBDDs, permitting the environmental occurrence and fate of such compounds to be studied.
authors.affiliation: Department of Chemistry, Umeå University.
authors.forename: Peter
authors.initials: P
authors.lastname: S Haglund
authors.affiliation: Department of Applied Environmental Science, Stockholm University.
authors.forename: Karin
authors.initials: K
authors.lastname: Löfstrand
authors.affiliation: Leco Corporation.
authors.forename: Kevin
authors.initials: K
authors.lastname: Siek
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University.
authors.forename: Lillemor
authors.initials: L
authors.lastname: Asplund
keywords: GC×GC; dioxins; emerging pollutants; halogenated natural products; multi-reflectron TOF; screening