Photolysis of difloxacin and sarafloxacin in aqueous systems.
Photolysis of difloxacin and sarafloxacin in aqueous systems.
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DOI：
10.1016/j.chemosphere.2009.08.031
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发表时间：
2009-10
期刊：
影响因子：
8.8
通讯作者：
D. Prabhakaran;P. Sukul;M. Lamshöft;M. Maheswari;S. Zühlke;M. Spiteller
中科院分区：
文献类型：
--
作者：
D. Prabhakaran;P. Sukul;M. Lamshöft;M. Maheswari;S. Zühlke;M. Spiteller
首次研究了氟喹诺酮类兽用抗生素二氟沙星（DIF）和沙拉芬（SARA）在水溶液中的光降解。进行研究以评估pH、无机物、腐殖物质和其他添加剂的影响。药物在无基质水介质中遵循一级降解动力学，DIF和SARA的速率常数“k”值分别为0.82和0.26 h − 1。在不同pH下进行的研究表明，DIF的光解速率在pH >7时急剧下降，而SARA随着pH的增加而消散得更快。腐殖物质通过减弱光强度而起到光屏障的作用，以延缓药物降解过程。然而，快速药物消散观察到在添加剂如丙酮，过氧化氢，磷酸盐的存在下，而无机物，如氟化物，硝酸盐，硫酸盐没有影响药物的光降解。对DIF和SARA在河水中的光解研究表明，这两种药物在与自然系统相关的条件下，遵循直接光解机制迅速降解。观察到SARA是DIF的初级光产物，并且比DIF表现出相对较高的持久性。量子产率（QDC）计算也证实了这一发现。采用LC-MS/MS进行分析测量。
The photodegradation of two fluoroquinolone veterinary antibiotics, difloxacin (DIF) and sarafloxacin (SARA) has been explored for the first time in aqueous systems. The study was performed to evaluate the influence of pH, inorganics, humic substances, and other additives. The drugs followed first-order degradation kinetics in matrix free aqueous medium with a rate constant ‘k’ value of 0.82 and 0.26h−1for DIF and SARA, respectively. Studies performed at various pH revealed that the photolysis rates dropped sharply at pH >7 for DIF, while SARA dissipated faster with increasing pH. Humic substances acted as light barriers by attenuating the light intensity, to retard the drug degradation process. However, rapid drug dissipation was observed in the presence of additives like acetone, hydrogen peroxide, and phosphates, while inorganics such as fluoride, nitrate, and sulfate did not influence the drug photodegradation. Studies on the photolysis of DIF and SARA in river water revealed that both the drugs degraded rapidly under conditions that were relevant to natural systems, following direct photolysis mechanism. It was observed that SARA was the primary photoproduct of DIF and showed relatively a higher persistence than DIF. The findings were also substantiated by the quantum yield (Фc) calculations. The analytical measurements were carried out with LC–MS/MS.