微量金的单扫描示波极谱测定

DETERMINATION OF TRACE GOLD BY SINGLE-SCAN OSCILLOPOLAROGRAPHY

本文报道金在巯基苯骈噻唑(MBT)的强酸性介质中于-0.95Ⅴ(Vs.S.C.E.)产生一灵敏的示波极谱波,波高随金量增加而线性增长,线性范围依赖于MBT用量,当MBT为0.2μg/25ml时,金的线性范围为0.002～0.1μg/ml。配合巯基棉分离干扰元素,已成功用于地质样品的分析。

Gold yields a sensitive oscillopolarographic wave at -0.95V (vs SCE) in an acid medium of 2-mercaptobenzothiazole (MBT). The results show that the linear range for Au (Ⅲ) depends on MBT concentration. There is a linear relationship between the height of the wave and the concentration of 1×10^(-8)—4×10^(-7) mol/L in a solution of 1.4 mol/L H_2SO_4-2％ NH_4Cl-0.01 μg/ml MBT. The influence of foreign ions on the height of wave has been examined. The method has been successfully applied to determine trace gold in geological samples by separating with sulfhydryl cotton fiber. The mechanism and behaviour of polarographic wave of Au have been studied as well.