Zhang Ya, Li Jianhua, Zhou Lei, Wang Guoqing, Feng Yanhong, Wang Zunyao, Yang Xi
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.
Environ Sci Pollut Res Int. 2016 Apr;23(7):6982-9. doi: 10.1007/s11356-015-5897-1. Epub 2015 Dec 26.
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.
近年来，抗菌剂在自然环境中的出现受到了科学界的关注。作为内分泌干扰化学物质，它们对生态系统和人类具有潜在风险。在本研究中，考察了氟苯尼考在水生系统中太阳光和氙灯照射下的光降解动力学及途径。氟苯尼考在太阳光照射下的直接光解半衰期分别为187.29小时，在氙灯照射下为22.43小时。发现活性氧（ROS），如羟基自由基（·OH）和单线态氧（(1)O2）在间接光解过程中起重要作用。硝酸盐和溶解有机物（DOMs）的存在可通过光屏蔽效应、猝灭效应和光诱导氧化过程影响氟苯尼考在溶液中的光解。采用固相萃取-液相色谱-质谱（SPE-LC-MS）分析技术鉴定了DOMs溶液中氟苯尼考的光产物，并提出了降解途径，包括光诱导水解、(1)O2和·OH氧化、脱氯和侧链裂解。
