不同pH值下环丙沙星的形态分布及光解研究.doc

不同pH值下环丙沙星的形态分布及光解研究 尉小旋 ，陈景文*，乔显亮，葛林科，张思玉 工业生态与环境工程教育部重点实验室，大连理工大学环境学院，116024，大连 E-mail: jwchen@dlut.edu.cn 光化学转化是影响天然水中抗生素环境归趋的重要因素。考察了喹诺酮类抗生素环丙沙星ciprofloxacin, CIP)在不同pH值条件下的光化学反应动力学。环丙沙星的光解pH = 2.0~12.0范围内先后，在pH左右最快。UV-vis滴定与正定矩阵因子分解不同形态UV-vis光谱及光解量子产率。λ 315 nm时，随pH增大环丙沙星的吸光光谱发生蓝移，而当λ 315 nm时，其吸收光谱发生红移。不同形态环丙沙星的光解量子产率具有明显差异(p 0.05)，导致其光解速率差异较大。中性分子的光解量子产率最大，光解最快，其次是碱性分子和酸性分子。 Fig. 1 Structure and protonation states of CIP. Fig. 2 pH dependence of CIP photolysis rate. Error bars represent the 95% confidence interval (n = 3). 关键词环丙沙星；pH值；解离形态；光解Larsson D G J, De Pedro C, Paxeus N. J Hazard Mater, 2007, 148(3):751-755. [2] Ge L K, Chen J W, Qiao X L, Lin J, Cai X Y. Environ Sci Technol, 2009, 43(9):3101-7. [3] Ge L K, Chen J W, Wei X X, Zhang S Y, Qiao X L, Cai X Y, Xie Q. Environ Sci Technol, 2010, doi: 10.1021/es902852v. Study on the Speciation and Photodegradation of Ciprofloxacin at Different pH Values Xiao-Xuan Wei, Jing-Wen Chen,* Xian-Liang Qiao, Lin-Ke Ge, Si-Yu Zhang Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, 116024, Dalian Photodegradation plays a central role in determining the environmental fate of antibiotics in natural waters. The pH dependence of ciprofloxacin (CIP) protonation states and photolysis was investigated. The photolysis rate of CIP was increased from pH 2 to 8 and decreased from pH 8 to 12. The UV-vis absorption spectra and the photodegradation quantum yield (Φ) of each protonation state were obtained by the method of UV-vis titration combined positive definite matrix factorization (PMF). The maximum absorption of CIP at λ 315 nm was blue shifted and at λ 315 nm was red shifted with pH increasing. Φ of CIP at different speciation varied significantly, leading to totally different photolysis rate. Neutral form degrades the fastest with the largest Φ, followed by anionic form and cationic form. 欢迎阅读本文档！ ｓｕｎｓｈｉｎｅ ｓｕｎｓｈｉｎ