应用洛美沙星(LMX)-茜素-镧形成的三元化合物,在紫外光区有明显的吸收,最大吸收波长为286 nm,在0.7~12 mg·L-1范围内服从比耳定律.其摩尔吸光系数为4.2×104L·mol-1·cm-1.应用此方法分析了洛美沙星胶囊中LMX的含量，所得结果与文献<参考文献原文>方法的结果一致.测定结果的平均RSD值为0.95%,回收率的平均值为101.1%.加入反应物的次序对测定结果有影响,必须按照先加洛美沙星,其次茜素,最后加镧的顺序.反应物的最佳摩尔比为1∶1∶2(洛美沙星∶茜素∶镧),以氯仿作为溶剂.反应的温度和时间对测定结果影响不明显.反应产物在2 h内稳定.

Based on the absorption behavior of the ternary complex formed among lomefloxacin,alizarin and lanthanum in the ultra-violet band with its absorption maxima at 286 nm,an UV-spectrophotometric method for the determination of lomefloxacin was proposed.Linear relationship between the absorbance and concentration of lemofloxacin was found in the range of 0.7-12 mg·L-1,with molar absorptivity of 4.2×104L·mol-1·cm-1.As shown by experimental results,the addition of reagents should be in the order of adding firstly alizarin solution to the sample solution containing lomefloxacin,and then adding the La(Ⅲ) solution.The mole ratio of the ternary complex was found to be [lomefloxacin∶alizarin∶La(Ⅲ)] 1 to 1 to 2.Chloroform was used as solvent to remove excess of alizarin by extraction.The ternary complex was stable within 2 h.Temperatures within the range of 20-70 ℃ were tolerable for the complexing reaction.In the analysis of a sample of lomefloxacin capsules,the results obtained by this method were found in consistency with the labelled value and also with the results obtained by the method given in literature<参考文献原文>,Average values of RSD′s was 0.95% and of recovery was 101.1%.