贵金属元素电分析化学研究(Ⅶ)--CCX富集、分离-阳极溶出伏安法测定金

Electrochemical Studies on Precious Metal Elements(Ⅶ)--CCx Enrichment and Separation-Determination of Gold

阳极溶出伏安法(ASV)测定金,多采用石墨电极,碳糊电极和玻碳电极。除后者有较高灵敏度外,多数非但处理电极较麻烦,而且常需采用活性炭吸附或萃取分离等手续,如此诸多不便。作者曾用巯基棉选择富集后,在0.36M柠檬酸钠+0.5MNaCl+7.5×10^(-6)MHg(Ⅱ)(pH=5.4)支持电解质中,用玻碳电极ASV同时测定了贵金属样中的Au和Pd。

The conditions of the determination of gold were studied on glass carbon electrode by the anodic stripping voltammetry(ASV).The experiments showed that in the optimum electrolytic system of 0.lM HCl-1.4×10^(-6)M HgCl_(2),there was a stable stripping peak for Au at about+0.8V(vs.S.C.E).Its determination limit reached 5 ppb.By adopting of cotton cellulose xanthate(CCX)for entichment,the separation of Au achieved good results.This method was used for some practical sample analyses with good results.The coefficient variation was 0.73%and 2.53%respectively when two gold samples were repeatedly determined for 7 times.