中文摘要：

采用固相萃取分离富集，LC—MS-MS为检测平台，研究了水环境中低浓度（10mg／L）红霉素和罗红霉素的光降解效率及其影响因素。结果表明，在接近中性（pH=7．5）的水溶液中，经过1h的光照，两种抗生素的光降解率在30％以下；而在有2000mg／LTiO2催化剂存在时，光照15min，二者的降解率即可分别达95．5％和97．2%,此时溶液的pH值对光催化降解的影响不大。实验也表明，光直接降解反应和光催化降解反应均符合一级反应动力学。

英文摘要：

The photochemical behavior of representative macrolide antibiotics including erythromycin （ETM） and roxithromycin （RTM） in water has been studied upon irradiation as well as photocatalysed treatment using solid phase extraction following LC-MS-MS determination. The effects of pH, TiO2 content and irradiation time on the antibiotics were investigated. The results showed that the photolytic ratios of ETM and RTM were below 30%, when irradiated for l h at pH 7.5; however, their photolytic ratios could be increased to 95.5% and 97.2% respectively in 15 min when 2000 mg/L of TiO2 was added and less effect from pH value was found. Both the photodegradation and the photocatalytic degradation procedures obey the first-order reaction kinetics.