title: Synthesis, liquid chromatographic fractionation and partial characterization of polybrominated dibenzofuran congeners.
abstract: Polybrominated dibenzofurans (PBDFs) are a class of highly toxic environmental contaminants which comprises 135 structurally different congeners. While the gas chromatographic separation and analysis of the most polychlorinated dibenzofurans (PCDFs) are well-documented, comparably little data is currently available in the case of PBDFs. In this study dibenzofuran was brominated to give a mixture of ∼40 PBDFs with one to seven bromine atoms. This synthesis mixture was fractionated by both countercurrent chromatography (CCC) with the solvent system n-hexane/toluene/acetonitrile and non-aqueous reversed-phase high performance liquid chromatography (RP-HPLC) with acetonitrile as the mobile phase. All together 80 consecutive CCC fractions and 40 HPLC fractions were taken and analyzed for PBDFs by gas chromatography coupled to mass spectrometry (GC/MS). CCC and RP-HPLC offered orthogonal separation of the PBDF mixture. As a consequence, selected CCC fractions were further fractionated by RP-HPLC. In this way, eight PBDFs could be isolated and the structures of twelve PBDFs were elucidated by proton magnetic resonance spectroscopy ((1)H NMR).
authors.affiliation: University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Gallistl
authors.affiliation: University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart, Germany. Electronic address: walter.vetter@uni-hohenheim.de.
authors.forename: Walter
authors.initials: W
authors.lastname: Vetter
mesh_terms: D001572:Benzofurans / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003377:Countercurrent Distribution; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry; D006586:Hexanes / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014050:Toluene / Q000737:chemistry
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004785:Environmental Pollutants; D006586:Hexanes; D012997:Solvents; C026385:n-hexane; D014050:Toluene; C023614:dibenzofuran
keywords: Countercurrent chromatography; Polybrominated dibenzofurans (PBDFs); Polyhalogenated compounds; RP-HPLC; Structure elucidation; Synthesis