卷积溶出伏安法测定痕量金的研究及其应用

研究提出测定痕量金的卷积溶出伏安法。在0.05mol/L盐酸-0.05mol/L氯化钠底液中,2.5次微分阳极溶出法测定金,线性范围为1～10ng/mL,检出限达0.5ng/mL(2.5 x10~(-9)mol/L)。结合大孔巯基树脂或巯基棉富集分离,巳用于岩矿及铜系列物料的分析,取得了满意的结果。该法灵敏度高、准确,操作较简便、易掌握,所用仪器价廉,适于快速分析。

DETERMINATION OF TRACE AMOUNTS OF GOLD BY CONVOLUTION ANODIC STRIPPING VOLTAMMETRY

A new method for determination of trace amounts of gold by convolution anodic stripping voltammetry has been developed. The interference of the co-existing elements and their elimination were studied. By using a higher automatic polarograph (Model: 83-2.5, made in China), the optimum determining conditions were selected as follows: Supporting electrolytes were respectively 0.1 mol/L HC1 for semi-differential and 1.5 derivative, and 0.05 mol/L HC1-0.05 mol/L NaCl for 2.5 derivative anodic stripping voltammetry. In both cases, deposition potential was at-1.0V (vs. SCE) and deposition time 2～5 min. The stirring rate was 1500 r/min. Delaying time before scanning was 30s. Potential scanned from 0 to +1.2V (vs. SCE) at the speed of 200 mV/s. Good linearity relationship between the concentration of gold and 2.5 derivative stripping peak height existed when the concentration of gold was 5X10-8～5X 10-9 mol/L. The detection limit was 2.5X10-9 mol/L, the relative standard deviation of determination was 1.90% for a sample of 3.59μg/g Au, and the recovery was 96～102%. The method is sensitive, accurate and easy to operate. By using big-aperture sulfhydryl resin or sulfhydryl cotton fiber to enrich gold and separate the co-existing impurities, the method has been successfully applied to determine trace amounts of gold in ores and samples in the process of copper metallurgy.