title: Investigation of photodegradation products generated after UV-irradiation of five polybrominated diphenyl ethers using photo solid-phase microextraction.
abstract: In this study, the photoinduced degradation of five polybrominated diphenyl ethers (PBDEs), BDE-47, BDE-100, BDE-99, BDE-154 and BDE-153, is studied using solid-phase microextraction polydimethylsiloxane fibers as photolytic support. PBDEs are extracted from aqueous solutions using SPME fibers that are subsequently exposed to UV irradiation for different times (from 2 to 60 min). Photodegradation kinetics of the five PBDEs, tentative identification and photochemical behavior of the generated photoproducts, as well as photodegradation pathways, have been studied employing this on-fiber approach technique (photo-SPME) followed by gas chromatography-mass spectrometry analysis. Aqueous photodegradation studies have also been performed and compared with photo-SPME. All the photoproducts detected in the aqueous experiments were previously found in the photo-SPME experiments. In this study, reductive debromination by successive losses of bromine atoms is confirmed as the main photodegradation pathway of PBDEs. A large number of PBDEs were obtained as photoproducts of the five target analytes. Other mechanism of photodegradation observed was intramolecular cyclization from the homolytic dissociation of the C-Br bond; thus, polybromo-dibenzofurans were generated. This work contributes to the study of the photodegradation of PBDEs and shows the potential of photo-SPME to evaluate the photo-transformation of organic pollutants.
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Lucia
authors.initials: L
authors.lastname: Sanchez-Prado
authors.forename: Maria
authors.initials: M
authors.lastname: Llompart
authors.forename: Marta
authors.initials: M
authors.lastname: Lores
authors.forename: Carmen
authors.initials: C
authors.lastname: Garcia-Jares
authors.forename: Rafael
authors.initials: R
authors.lastname: Cela
mesh_terms: D004987:Ethers / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D010777:Photochemistry; D011075:Polybrominated Biphenyls / Q000737:chemistry*; D012015:Reference Standards; D015203:Reproducibility of Results; D014466:Ultraviolet Rays
chemical_list: D004987:Ethers; D011075:Polybrominated Biphenyls