title: UV-induced formation of bromophenols from polybrominated diphenyl ethers.
abstract: Bromophenols (BPs) are both man-made industrial compounds and naturally produced secondary metabolites of algae and sponges. This study explored the formation of BPs by UV irradiation of polybrominated diphenyl ethers (PBDEs). Simulated sunlight (10-80 min) and natural sunlight irradiations (5 days) of BDE-153, BDE-154, BDE-183, BDE-196, and technical octabromodiphenyl ether (DE-79) generated hydrodebrominated PBDEs along with up to 0.7-4 mass % BPs. UV absorption spectra were recorded to show that the para-substituted PBDEs and BPs are those predominately transformed because this structural feature causes a significant bathochromic shift of λmax to higher wavelength. A decrease of higher brominated BPs in favor of lower brominated BPs was observed with time. All possible substitution patterns on the BPs formed by the cleavage of the parent PBDEs and respective hydrodebromination products were observed. The main di- and tribromophenols detected were 2,4-diBP > 2,5-diBP and 2,4,6-triBP > 2,4,5-triBP on average. The irradiation conditions were similar to real-world scenarios and emphasized the environmental relevance of these photolysis products of PBDEs. The meta-substituted BPs can be used as markers to distinguish photolytic PBDE transformation products from naturally produced BPs, which exclusively feature bromo-substitutents in ortho- and para-positions.
authors.affiliation: Institute of Food Chemistry, University of Hohenheim, Garbenstrasse 28, D-70599 Stuttgart, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Bendig
authors.forename: Walter
authors.initials: W
authors.lastname: Vetter
mesh_terms: D000042:Absorption; D008401:Gas Chromatography-Mass Spectrometry; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry* / Q000528:radiation effects*; D007536:Isomerism; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry; D011075:Polybrominated Biphenyls / Q000737:chemistry / Q000528:radiation effects; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D055768:Halogenated Diphenyl Ethers; D010636:Phenols; D011075:Polybrominated Biphenyls; D012997:Solvents; C517828:hexabrominated diphenyl ether 153; C533761:hexabromodiphenyl ether 154