title: Aqueous photodegradation of antibiotic florfenicol: kinetics and degradation pathway studies.
abstract: The occurrence of antibacterial agents in natural environment was of scientific concern in recent years. As endocrine disrupting chemicals, they had potential risk on ecology system and human beings. In the present study, the photodegradation kinetics and pathways of florfenicol were investigated under solar and xenon lamp irradiation in aquatic systems. Direct photolysis half-lives of florfenicol were determined as 187.29 h under solar irradiation and 22.43 h under xenon lamp irradiation, respectively. Reactive oxygen species (ROS), such as hydroxyl radical (·OH) and singlet oxygen ((1)O2) were found to play an important role in indirect photolysis process. The presence of nitrate and dissolved organic matters (DOMs) could affect photolysis of florfenicol in solutions through light screening effect, quenching effect, and photoinduced oxidization process. Photoproducts of florfenicol in DOMs solutions were identified by solid phase extraction-liquid chromatography-mass spectrometry (SPE-LC-MS) analysis techniques, and degradation pathways were proposed, including photoinduced hydrolysis, oxidation by (1)O2 and ·OH, dechlorination, and cleavage of the side chain.
authors.affiliation: State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Nanjing Institute of Environmental Sciences, Chinese Ministry of Environmental Protection, Nanjing, 210042, People's Republic of China.|State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Li
authors.affiliation: Université Lyon 1, UMR CNRS 5256, Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), 2 Avenue Albert Einstein, F-69626, Villeurbanne, France.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.affiliation: State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Nanjing Institute of Environmental Sciences, Chinese Ministry of Environmental Protection, Nanjing, 210042, People's Republic of China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Wang
authors.affiliation: State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Nanjing Institute of Environmental Sciences, Chinese Ministry of Environmental Protection, Nanjing, 210042, People's Republic of China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China.
authors.forename: Zunyao
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China. yangxi@nju.edu.cn.
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry*; D017665:Hydroxyl Radical; D007700:Kinetics; D008956:Models, Chemical; D009566:Nitrates / Q000737:chemistry; D010782:Photolysis; D026082:Singlet Oxygen; D012996:Solutions; D013472:Sunlight; D013839:Thiamphenicol / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D009566:Nitrates; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; D026082:Singlet Oxygen; D017665:Hydroxyl Radical; C035534:florfenicol; D013839:Thiamphenicol
keywords: Antibacterial agent; Dissolved organic matter; Florfenicol; Pathways; Photochemistry; Photodegradation; Reactive oxygen species