贵金属元素电化学分析研究(Ⅷ)——痕量铂的阳极溶出伏安法测定

Studies on Electrochemical Analysis of Precious Metals(Ⅷ) --Determination of Trace-Platinum by ASV

用伏安法或石墨电极阳极氧化伏安法测定痕量铂虽有报道,但其灵敏度均不够高。Ghulkina等发现在HCl介质中含Sn(Ⅳ)或Sn(Ⅱ),以Pt-Sn共沉淀在碳糊电极上,使铂的测定限达5×10-9g/L。本文用0.3mol/LH_(2)SO_(4)-Hg(Ⅱ)-3.0×10^(14)mol/L KMnO_(4)体系测Pt,其检测限为0.5μg/L。探讨了利用黄原酸钠纤维素酯(CCX)分离除去试液中Au^(3+)Pd^(2+)等干扰元素。本法已用于实际样品分析,结果较好。

A new method of determination of trace-platinum by anodic stripping voltammetry (ASV) has been established. By using the cotton cellulose xanthate (CCX) separation column to separate the main impurities of Au^(3+), Pd^(2+), etc, the filtrate of sample was treated by aqua regia and controlled in the optimun supporting electrolysis system of 0.3mol·L-1H_(2)SO_(4)-Hg(Ⅱ)-3.0 × 10^(-4)mol·L-1 KMnO_(4) for the purpose. The detection limit of Pt was 0.5ppb. The method was applied to the determination of platinum in several complicated samples, such as industrial waste water, refined mineral and chloridized residue. Its coefficient variations were 0.086, 0.041 and 0.027 respectively. The recovery of platinum in industrial waste water was in the range of 92-104%.