2-羟基-5-磺酸基苯基重氮氨基偶氮苯分光光度法测定铂(Ⅳ)

Spectrophotometric determination of platinum(Ⅳ) with 2-hydroxy-5-sulfo-benzenediazoaminoazobenzene

研究了2-羟基-5-磺酸基苯基重氮氨基偶氮苯（HSDAA）与Pt（Ⅳ）的显色反应。试验表明，在复配型微乳液CPB／OP存在下，pH11．7的NaOH溶液中，Pt（Ⅳ）与HSDAA形成1：2的淡黄色络合物，其最大吸收峰位于434nm波长处，表观摩尔吸光系数为ε=1．59×0^5L·mol^-1·cm^-1。Pt（Ⅳ）含量在0．04～10．0μg／10mL范围内符合比尔定律，方法检出限为1．14×10^-4g／L，本法用于铂催化剂中铂的分析，回收率为98．4％～103．5％，相对标准偏差为1．9％～2．2％，结果同原子吸收光谱法测定结果相吻合。

The chromogenic reaction of 2-hydroxy-5-sulfo-benzenediazoaminoazobenzene with platium（Ⅳ） was studied. In the presence of CPB/OP microemulsion,platium （Ⅳ） reacted with HSDAA to form a stable yellow complex（1 ： 2） in NaOH solution at pH 11.7. The maximum absorption wave- length and apparent molar absorptivity are 434 nm and 1.59 × 10^5 L ·mol^-1· cm^-1 , respectively. Beer＇s law is obeyed in the range of 0. 04-10 μg/10 mL for Pt（Ⅳ）. The detection limit of this method is 1.14 × 10^-6g/L. The method has been applied to the determination of Pt（Ⅳ） in platinum catalyst with the recovery of 98.4%--103.5% and the RSD of 1.9%-2.2%.The results were consistent with those of AAS.