偶氮蓝褪色光度法测定溴代十六烷基吡啶

基于偶氮蓝与溴代十六烷基吡啶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=5．2的缓冲溶液中，偶氮蓝在531nm波长处有一强的特征吸收峰，当在其溶液中加入溴代十六烷基吡啶后，溶液发生褪色反应，吸光度差值与溴代十六烷基吡啶浓度成正比。最佳条件下，溴代十六烷基吡啶的浓度在0～60μg／25mL范围内遵守比尔定律，检测限（3σ）为0．22μg/mL。方法用于溴代十六烷基吡啶的测定，回收率为97．3％-103．7％。

Fading Spectrophotometric Method for the Determination of Cetylpyridinium Bromide with Azo Blue

The interaction of Cetylpyridinium bromide and Azo blue was studied by fading spectrophotometry. In pH = 5.2 buffer solution, Azo blue had a strong absorbance at 531nm and the addition of Cetylpyridinium bromide in- to Azo blue solution resulted in the decrease in the absorbance value. The decrease in absorbance value was linear with the coneention of Cetylpyridinium bromide. Under the optimum conditions, Beer＇s law was obeyed in the range of 0-60 μg/25 mL, with the detection limit of 0.22 μg/mL. The mothed was applied to determine the sodium injection solution with satisfactory results. The recoveries were 97.3 -105.3%.