Analytical Chemistry Department, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt.
Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Environ Sci Pollut Res Int. 2017 Oct;24(30):23880-23892. doi: 10.1007/s11356-017-0045-8. Epub 2017 Sep 4.
Gemifloxacin (GEM) is a broad-spectrum quinolone antibiotic. The presence of GEM residuals in industrial and hospital wastewater has been associated with genotoxicity and antibiotic resistance. In this contribution, the photodegradation of GEM using titanium dioxide nanoparticles (TiONPs)/HO as a catalyst was optimized to eliminate residual drug and its photodegradates with antibacterial activity. A half-factorial design was implemented, investigating the effects of pH, initial concentration, HO concentration, TiONP loading, and irradiation time. Owing to the time-dependent, multi-transformation of GEM into a wide range of structurally related photodegradation products, the monitoring of GEM throughout the experiments was achieved using both HPLC and potentiometric ion-selective electrodes (ISE). The sensor enabled in-line tracking of residual GEM in the presence of its photodegradates in real time. Results indicated that the pH, irradiation time, and GEM initial concentration were the most significant factors. At the optimum set of experimental conditions, the reaction followed first-order reaction kinetics with a mean percentage degradation of ~ 95% in less than 30 min of irradiation time and almost complete loss of antibacterial activity against Escherichia coli. The promising results demonstrated the efficiency of UV/TiONP/HO as a photocatalyst for the breakdown of the pharmacophore of fluoroquinolones from water samples. The high selectivity, minimal solvent consumption, and lack of harmful waste generation confirmed the superiority of in-line monitoring using ISE. Optimization and in-line monitoring protocol should be applicable also at the pharmaceutical industry scale to eliminate the risk of antibiotic resistance.
加替沙星（GEM）是一种广谱喹诺酮类抗生素。工业和医院废水中存在 GEM 残留与遗传毒性和抗生素耐药性有关。在本研究中，采用二氧化钛纳米颗粒（TiONPs）/HO 作为催化剂优化了 GEM 的光降解，以消除具有抗菌活性的残留药物及其光降解产物。采用二因子析因设计，考察了 pH、初始浓度、HO 浓度、TiONP 负载和辐照时间的影响。由于 GEM 随时间的推移发生多转化，生成了一系列结构相关的光降解产物，因此在整个实验过程中使用 HPLC 和离子选择性电极（ISE）同时监测 GEM。该传感器能够在存在其光降解产物的情况下实时在线跟踪残留 GEM。结果表明，pH、辐照时间和 GEM 初始浓度是最重要的因素。在最佳实验条件下，反应遵循一级反应动力学，辐照时间小于 30 分钟时，平均降解率约为 95%，对大肠杆菌的抗菌活性几乎完全丧失。结果表明，UV/TiONP/HO 作为光催化剂可有效破坏水样中氟喹诺酮类药物的药效团。高选择性、低溶剂消耗和无有害废物生成证实了使用 ISE 在线监测的优越性。优化和在线监测方案也应适用于制药行业规模，以消除抗生素耐药性的风险。
