Dibenzofurans from

Fig. 5. Yields of Brominated Dibenzofurans from Decabromobiphenyl Ether as Dependent on Temperature and Amount of Sb203 (Synergist) in the Polymeric Matrix (Polybutylene-terephtalate).

FIGURE 7.1 Formation of dioxin and dibenzofuran (from Crosby 1998). 

Hashimoto, S., Ito, H., and Morita, M., Elution of polychlorinated dibenzo-p-dioxins and dibenzofurans from coffee filters, Chemosphere, 25(3), 297, 1992. (CA118 21237c)... 

Wang, L., Lee, W., Tsai, P, Lee, W., and Chang-Chien, G., Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans from stack flue gases of sinter plants, Chemosphere, 50(9), 1123-1129, 2003. 

Ma J, Kannan K, Cheng J, Horii Y, Wu Q, Wang W (2008) Concentrations, profiles, and estimated human exposures for polychlorinated dibenzo-p-dioxins and dibenzofurans from electronic waste recycling facilities and a chemical industrial complex in Eastern China. Environ Sci Technol 42(22) 8252-8259. doi 10.1021/es8017573... 

Lewis acids zinc chloride or aluminum chloride. Heat alone is sometimes effective, and the kinetics of the formation of dibenzofuran from 2,2 -biphenyldiol have been studied in both the presence and absence of zinc chloride. The rate and the degree of conversion are both markedly increased with increasing temperature under these conditions. ... 

Flash vacuum pyrolysis of dibenzothiophene 5,5-dioxide (244) affords a high yield of dibenzofuran. The sultine 245 (Scheme 63) was postulated as an intermediate, and this has been verified. Octafluorodibenzo-furan has been prepared by flash vacuum pyrolysis of the octafluoro analog of compound 244. The preparation of dibenzofuran from 2-phenoxyben-zenesulfonyl chloride by heating in the presence of a catalyst presumably involves the dioxide 244 as an intermediate. ... 

O Keefe PW. 1978. Fonnation of brominated dibenzofurans from pyrolysis of the polybrominated biphenyl fire retardant, Firemaster FF-1. Environ Health Perspect 23 347-350. 

Watanabe I, Tatsukawa R. 1987. Formation of brominated dibenzofurans from the photolysis of flame retardant decabromobiphenyl ether in hexane by UV and sun light. Bull Environ Contam Toxicol 39 953-959. 

As discussed in the earlier survey (1), a biogenic source of polychlorinated dibenzo-p-dioxins and dibenzofurans is peroxidase-catalyzed transformation of chlorophenols as first reported by Oberg and Rappe (2041-2044). More recent studies confirm these observations (2045-2048). In addition to lactoperoxidase and horseradish peroxidase, human leukocyte myeloperoxidase catalyzes in vitro formation of dioxins and dibenzofurans from chlorophenols (2046, 2047). Formation rates are in the pmol/mol range (Scheme 3.6) demonstrating that a human biosynthesis of dioxins and furans is not only possible but also likely. These observations are reinforced by the reported in vivo (rats) conversion of the pre-dioxin nona-chloro-2-phenoxyphenol to octachlorodibenzo-p-dioxin (OCDD) (2049), and the production of hepta- and octachlorodibenzo-p-dioxin in the feces of cows fed pentachlorophenol-treated wood (Scheme 3.7) (2050, 2051). 

Tanahashi T, Takenaka Y, Nagakura N, Hamada N (2001) Dibenzofurans from the Cultured Lichen Mycobionts of Lecanora cinereocarnea. Phytochemistry 58 1129... 

Takenaka Y, Hamada N, Tanahashi T (2005) Monomeric and Dimeric Dibenzofurans from Cultured Mycobionts of Lecanora iseana. Phytochemistry 66 665... 

Wittsiepe J, Kullmann Y, Schrey P, Selenka F, Wilhelm M (1999) Peroxidase-Catalyzed in Vitro Formation of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans from Chlorophenols. Toxicol Lett 106 191... 

Lemieux PM, Lutes CC, Abbott JA, Aldous KM (2000) Emission of Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans from the Open Burning of Household Waste in Barrels. Environ Sci Technol 34 377... 

Pyle and Marcus [ 102] achieved low ppb detection limits for the determination of organochlorine insecticides in soil using accelerated solvent extraction followed by gas chromatography ion trap tandem mass spectrometry. Richter et al. [103] showed that accelerated solvent extraction gave essentially equivalent recoveries of chlorinated dibenzo-p-dioxins and dibenzofurans from soil compounds to Soxhlet extraction, but in less time and using much less solvent. 

The bis-basic ester of the dibenzofuran from the cited art is structurally similar to the Markush genus disclosed in Albrecht s application but does not fall within it since the core structure is a dibenzofuran and that of Albrecht is a carbazole.27 This... 

Kuehl, D.W., Cook, P.M., Batterman, A.R., Lothenbach, D., Butterworth, B.C. (1987) Bioavailability of polychlorinated dibenzo-p-dioxins and dibenzofurans from contaminated Wisconsin river sediment to carp. Chemosphere 16(4), 667-679. 

Carsch S, Thoma H, Hutzinger 0. 1986. Leaching of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans from municipal waste incinerator fly ash by water and organic solvents. Chemosphere 15 1927-1930. 

Kuehl DW, Cook PM, Batterman AR, et al. 1987c. Isomer dependent bioavailability of polychlorinated dibenzofurans from municipal incinerator fly ash to carp. Chemosphere 16 657-666. 

Smith RM, O Keefe PW, Hilker DR, et al. 1986b. Sampling, analytical method and results for chlorinated dibenzo-p-dioxins and chlorinated dibenzofurans from incinerator stack effluent and contaminated building indoor air samples. In Rappe C, Choudhary G, Keith LH, eds. Chlorinated dioxins and dibenzofurans in perspective. Chelsea, MI Lewis Publishers, Inc., 93-108. 

Van den Berg M, Olie K, Hutzinger 0. 1983. Uptake and selection in rats of orally administered chlorinated dioxins and dibenzofurans from fly-ash and fly-ash extract. Chemosphere 12 537-544. 

Briois, C., Ryan, S., Tabor, D., Touati, A. and Gullett, B.K. (2007) Formation of polychlorinated dibenzo- -dioxins and dibenzofurans from a mixture of chlorophenols over fly ash Influence of water vapor. Environ. Sci. Technol. 41, 850-856. 

Lamparski LL, NestrickTJ (1989), Chemosphere 18 1761-1770.. .Micro-scale bromination procedure for synthesis of, 2,3,7,8-substituted" brominated dibenzo-p-dioxins and dibenzofurans from [lsC]-labeled precursors"... 

U.S. Environmental Protection Agency (EPA) (1991), Fed. Regist. 56 5758-5775. Method 23 Determination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans from stationary sources", Washington, D.C. 

Hagenmaier H, Dawidowsky N, WeberruB U, Hutzinger O, Schwind KH, Thoma H, Essers U, Biihler U, Greiner R (1990), Organohalogen Compounds 2 329-334.. .Emissions of polyhalogenated dibenzodioxins and dibenzofurans from combustion engines", Eco-Informa Press, Bayreuth... 

Buser HR, Bosshardt HP, Rappe C (1978), Chemosphere 7 109-119.. .Formation of polychlorinated dibenzofurans from the pyrolysis of PCBs"... 

Hites RA, Brzuzy LP (1995), Environ. Sci. Technol. 29 2090-2098.. .Estimating the atmospheric deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans from soils"... 

Compare the inluilation risk for tlie emission of 100 pg/m of arsenic witli unit risk of 3.30 x 10 (pg/nv ) ) and dioxin/dibenzofunm witli unit risk of 3.80x10 (pg/m ) ). Also how much arsenic is equivalent to 100 lb of dioxin/dibenzofuran from an inhalation risk perspective ... 

Zhao X, Zheng M, Zhang B, et al. Evidence for the transfer of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and poly chlorinated dibenzofurans from soils to biota. Sci Total Environ 2006 368(2-3) 744-52. 

TABLE 11.13 Electron Affinities (in eV) of Chlorinated Anthracenes, Xanthene, and Dibenzofuran from ECD Data... 

Fig. 2 Transient flux of dibenzofuran from soil to air in laboratory apparatus demonstrating the effect of soil moisture. (From Ref. l)...

Ritter, E.R. Bozzelli, J.W. Pathways to chlorinated dibenzodioxins and dibenzofurans from partial oxidation of chlorinated aromatics by OH radical—thermodynamic and kinetic insights. Combust. Sci. Tech. 1994, 101, 153-169. 

These results clearly showed the relative significance of different routes of exposure, and the varying degrees of mobility after uptake. This is consistent with results for the uptake of polychlorinated dibenzo[l,4]dioxins and dibenzofurans from soils. In zucchini and pumpkin belonging to the genus Cucurbita, root uptake was dominant, whereas for cucumber (Cucumis sati-vus) foliar uptake was the primary mode and was much lower (Hulster et al. 1994). 

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