荷移增敏分光光度法测定甲硝唑片中甲硝唑的含量

Enhanced spectrophotometric determination of metronidazole in tablets based on charge-transfer reaction

目的:建立用荷移增敏分光光度法测定甲硝唑片中甲硝唑含量的方法。方法:利用甲硝唑与氯冉酸在丙酮-氯代十六烷基吡啶(CPC)介质中形成稳定络合物,在513nm波长处测定络合物的吸光度。结果:甲硝唑浓度在12～250mg·L^(-1)范围内线性关系良好,相关系数(r)0.9994,检出限4.09mg·L^(-1),RSD为0.49%～1.26%(n=6),回收率99.0%～100.9%。结论:本法简便快速,条件易控制,测定结果与中国药典方法一致。

Objective：To establish a enhanced spectrophotometric method for the determination of metronidazole in tablets through charge - transfer between metronidazole and chloranilic acid. Method： Metronidazole reacted with chloranilic acid to form a charge - transfer complex in acetone - cetylpyridinium chloride （CPC） and could be quantitatively determined at 513 nm. Results： The linear range of metronidazole was 12 -250 mg · L^-1 and the correlation coefficient was 0. 9994 with a detection limit of 4. 09 mg·L^-1. The method has been used for the determination of metronidazole in tablets with 0. 49% - 1.26% RSD （n = 6）. The recoveries were 99. 0% - 100. 9%. Conclusions：The method is simple with easily -controlled reaction conditions and high sensitivity. The results accord with the ChP.