铑(Ⅲ)与2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺的氢催化波研究

A Study on the Catalytic Hydrogen Wave of Rhodium With 2-(5-Bromo-2-pyridylazo)-5-dimethylamino Aminobenzene

在单扫示波极谱仪上,铑与新试剂5-Br-PADMA在pH=5.20的HAc-NaAc介质中于-1.14V产生—灵敏的极谱催化波。利用该波可测定3.8×10^(-9)mol/L～1.9×10^(-6)mol/L的铑,检出限达9.7×10^(-10)mol/L。研究了催化波的性质及影响因素,确定该波属于Rh-5-Br-PADMA配合物的氧催化波。测定了几种催化剂中铑的含量。

By using single-sweep oscillopolarograph, the complex of rhodium with 2-(5-bromo-2-pyridylazo)-5-dimethylamino aminobenzene can produce a sensitive polarographic catalytic wave in acetate buffer media at pH 5.20 at -1.14V(vs.SCE). The peak height is linear with rhodium concentration from 3.8×10^(-9)mol/L to 1.9×10^(-6)mol/L and the detection limit can reach 9.7×10^(-10)mol/L. The properties and influence factors of the catalytic wave have been researched. It has been proved that this wave is a catalytic hydrogen wave by several electrochemical methods. The method has been applied to the determination of trace rhodium in some Rh-catalysts with satisfactory results.