title: Photochemistry of tetra- through hexa-brominated dioxins/furans, hydroxylated and native BDEs in different media.
abstract: The aim of this study was to investigate (i) the behavior of native PBDEs during UV irradiation in different media, (ii) the possibility of their transformation into hydroxylated PBDEs in aqueous media, and (iii) the photochemistry/levels of brominated dioxins/furans formed from hydroxylated PBDEs. Debromination leading to the formation of a wide range of low-brominated congeners was the main path of photocatalyzed transformations of PBDEs. In organic solvents other than toluene, BDEs degraded in line with the pseudo first order kinetics (10-20 min half-life, depending on congener type and reaction medium). Irradiated BDE 209 congener behaved quite differently than lower-brominated BDEs: detectable amounts of various bromo-benzenes were found. That suggests that UV irradiation of BDE 209 leads to cleavage of the ether bound between the congener's aromatic rings. Formation of bromophenyl bromo-methyl-biphenyl ethers or benzyl-bromophenoxybenzenes was observed in irradiated PBDE toluene-based solutions. The total concentration of OH-BDEs found in the reaction medium did not exceed 0.2% of the initial precursor mass. Moreover, lower-brominated congeners detected in the reaction medium indicate subsequent debromination of OH-BDEs or hydro-debromination of the degraded congeners. Brominated dioxins and low levels of furans were observed in samples containing OH-BDEs. The total mass of dioxins did not exceed 3.5% of the initial precursor mass.
authors.affiliation: Department of Food Analysis, Institute of Agricultural and Food Biotechnology, Rakowiecka 36, 02-532, Warsaw, Poland. roszko@ibprs.pl.
authors.forename: Marek
authors.initials: M
authors.lastname: Roszko
authors.affiliation: Department of Food Analysis, Institute of Agricultural and Food Biotechnology, Rakowiecka 36, 02-532, Warsaw, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Szymczyk
authors.affiliation: Department of Food Analysis, Institute of Agricultural and Food Biotechnology, Rakowiecka 36, 02-532, Warsaw, Poland.
authors.forename: Renata
authors.initials: R
authors.lastname: Jędrzejczak
mesh_terms: D004147:Dioxins / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006207:Half-Life; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry*; D006900:Hydroxylation / Q000528:radiation effects; D015394:Molecular Structure; D010777:Photochemistry; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D004147:Dioxins; D005663:Furans; D055768:Halogenated Diphenyl Ethers; D014874:Water Pollutants, Chemical
keywords: Brominated dioxins; Degradation; OH-BDE; PBDE; UV