在pH=3.55的NaAc-HAc缓冲溶液中,左氧氟沙星对刚果红(CR)和孔雀石绿(MG)反应生成的产物在可见光区有明显的作用,在618 nm波长处测定其吸收强度,结果表明体系的吸光度与左氧氟沙星的浓度在2~60μg.mL-1范围内呈现良好的线性关系,线性相关系数R=0.9905,检出限为0.053μg.mL-1。该方法可用于盐酸左氧氟沙星片剂、胶囊以及尿液中左氧氟沙星含量的测定。
In a NaAc-HAc buffer solution(pH=3.55),the absorbance of the chelate complex between congo red(CR) and malachite green(MG) was enhanced by levofloxacin(LVFX),and a method for the determination of levofloxacin was therefore developed by spectrophotometric measurement at 618 nm.A good linearity in the range of 2~60 μg/mL and a detection limit of 0.053 μg/mL were obtained.The method has been applied to the determination of levofloxacin in tablets,capsules and urine samples and compared to the pharmacopoeia method with satisfactory results.