褪色光度法测定硫酸庆大霉素的研究

Fading Spectrophotometric Method for the Determination of Gentamycin Sulfate with Azo blue

基于偶氮蓝与硫酸庆大霉素相互作用而导致溶液吸收光谱的变化，用褪色光度法对该体系进行了研究。在pH=4．10的缓冲溶液中，偶氮蓝在553nm波长处有一强的特征吸收峰，当在其溶液中加入硫酸庆大霉素后，溶液发生褪色反应，553nm处吸收强度降低，吸光度差值与硫酸庆大霉素质量浓度成正比。最佳条件下，硫酸庆大霉素的质量浓度在0．1～3．2mg·L^-1范围内遵守比尔定律，表观摩尔吸光系数￡=6．8×10^4L·mol^-1·cm^-1，检测限（3σ）为0．087mg·L^-1。方法用于硫酸庆大霉素注射液的测定，回收率为97．2％～100．2％。

The interaction of Gentamycin Sulfate and Azo blue was studied by fading spectrophotometry. In pH = 4.10 Britton Robinson buffer solution, Azo blue had a strong absorbance at 553 nm and the addition of Gentamycin Sulfate into Azo blue solution resulted in the decrease in the absorbance value at 553nm. The decrease in absorbance value was linear with the concention of Gentamycin Sulfate. Under the optimal conditions, Beer＇ s law was obeyed in the range of 0.1 - 3.2 mg· L^- 1, with apparent molar absorptivity of 6.8 ×10^4 L·mol^- 1· cm^- 1 and the detection limit of 0. 092 mg· L^- 1. The mothed was applied to determine the sodium injection solution with satisfactory results. The recoveries obtained were 97.2 % - 100.2%.