CCl_4增强超声降解环丙沙星的效果及路径解析

The Enhanced Effect of Ciprofloxacin Sonochemical Degradation by Adding CCl_4 and its Degradation Pathways

研究考察了CCl4增强超声降解喹诺酮类抗生素环丙沙星的效果,通过·OH浓度的测定和异丙醇对反应的抑制情况探索环丙沙星的超声降解机理;采用UPLC/MS/MS方法对降解产物进行分析,解析环丙沙星的降解路径。结果表明,CCl4增强了环丙沙星的超声降解,当反应液体积为100 m L,超声40 min,随着CCl4添加浓度的增大（0-41.4mmol·L^-1）,环丙沙星的降解率由0.51%增至50.92%;荧光探针分析和异丙醇抑制结果表明增强作用主要在于·OH和一系列氯自由基的氧化;UPLC/MS/MS分析发现,降解过程中生成8种产物,其中包括3种氯代产物,环丙沙星按照6种途径进行降解。研究结果有助于深入研究CCl4增强超声降解抗生素的机理,提高过程处理效果。

Enhanced ultrasonic degradation of ciprofloxacin by adding CCl4 was investigated. Fluorescence probe analysis and radical scavenging experiments were carried out to identify active species, and UPLC/MS/MS techniques were used to confirm the intermediates formed. Possible degradation pathways were also proposed. The experimental results show that the ciprofloxacin ultrasonic degradation is evidently enhanced by the addition of CCl4. When CCl4 concentration increased from 0 to 41.4 mmol.L＆-1, ciprofloxacin degradation efficiency increases from 0.51% to 50.92%. The enhancement is due to the increase of .OH radical concentration and formation of chlorine-containing radicals. UPLC/MS/MS results reveal that eight intermediate products are formed during the ultrasonic degradation of ciprofloxacin in the presence of CCl4, which include three chloro-products. The degradation of ciprofloxacin was identified through six ways. This study can help to better understand mechanisms of CCl4-enhanced ultrasonic degradation processes and develop new effective methods for quinolone antibiotics removal from aqueous solutions.