茜素褪色光度法测定罗红霉素的含量

Fading spectrophotometric method for the content determination of roxithromycin with alizarin

罗红霉素（ROM）与茜素（ALZ）在pH5．5～6．6的酸性介质中反应生成红色络合物，使茜素溶液褪色，最大褪色波长位于428nm表观摩尔吸光系数（￡）为1．04×10^4L／（mol·cm）；线性范围为0．2～18．0mg／L。罗红霉素在一定浓度范围内遵从比耳定律，据此建立了测定罗红霉素含量的分光光度法，并探讨了适宜的反应条件和主要分析化学性质。该法用于市售罗红霉素制剂中罗红霉素含量的测定，结果满意。

In pH 5. 5～6.6 acid medium, alizarin （ALZ） react with roxithromycin （ROM） to form red complex, which fades the color of alizarin （ALZ） solution. The maximum fading wavelength was 428nm, the apparent molar absorptivities （ε） was 1.04×10^4L/（mol·cm）; the linear ranges was 0. 2～18.0 mg/L. The concentration of roxithromycin in definite range obeys Lombard Beer＇s law. A new spectrophotometric method for the determination of roxithromycin （ROM） has been developed. The optimum reaction conditions and the main analytical parameters were investigated. The method was applied to determine the content of roxithromycin （ROM） with satisfactory results.