Synthesis and analysis of mixed chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans and assessment of formation and occurrence of the fluorinated and chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans.
Various mixtures of chlorinated-fluorinated dibenzodioxins (PCFDD), dibenzofurans (PCFDF) and biphenyls (PCFB) were synthesized. For trace analysis, we compared the behavior of PCFDD/PCFDF and chlorinated congeners in extraction, enrichment and clean-up steps. To establish GC/MS analysis, various columns were tested, temperature programs were optimized and for MS-identification specific masses were selected from the mass spectra. To evaluate the possibility of formation of these compounds in thermal processes, samples from the aluminum-producing industry and products of pyrolysis of chlorofluoro- hydrocarbons (FCKW) on a laboratory scale were analyzed. At present, the most important potential sources of fluorinated or mixed chlorinated-fluorinated dioxins, furans and biphenyls - combustion processes and large scale chemical production - do not cause significant environmental contamination at least in the areas considered. However, in a sample of filter dust from the refining process of aluminum using freon 12 we found high amounts (4.5 g/kg !) of chlorinated and chlorinated-fluorinated aromatic compounds including chlorinated-fluorinated dibenzofurans and biphenyls. Since the FCKW ban in Europe, this procedure was modified in 1992, replacing freon 12 by a mixture of chlorine and argon. The PFDD/PFDF concentration in the fluorophenols was between 0.45 and 120 micrograms/kg. The fluorobenzenes analyzed contained between 15 and 70 mg/kg fluorinated biphenyls.
Weber
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R
Institute of Organic Chemistry University of Tübingen, FRG.
Hagenmaier
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H
D001572:Benzofurans / Q000138:chemical synthesis* / Q000737:chemistry; D005617:Chlorofluorocarbons, Methane / Q000378:metabolism; D000072338:Dibenzofurans, Polychlorinated; D004781:Environmental Exposure; D008401:Gas Chromatography-Mass Spectrometry; D016273:Occupational Exposure; D011078:Polychlorinated Biphenyls / Q000138:chemical synthesis* / Q000737:chemistry; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D012989:Soil Pollutants
D001572:Benzofurans; D005617:Chlorofluorocarbons, Methane; D000072338:Dibenzofurans, Polychlorinated; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls