共沉淀-感耦等离子体质谱法测定地质样品中的超痕量金铂钯

Determination of Ultra-trace Au, Pd and Pt in Geochemical Samples by Co-precipitation ICP/MS

本工作研究提出了共沉淀富集结合ICP-MS测定地质样品中的金、铂、钯的方法,研究了仪器的最佳化和内标元素的选择。在本工作的实验条件下获得的方法测定下限以6倍标准偏差计分别为Au:0.23 ng·g-1,Pt:0.19 ng·g-1,Pd:0.16 ng·g-1;方法精密度(RSD)Au:1.4％-18.2％,Pt:0.2％-16.4％,Pd:0.4％-13.6％。采用本工作制定的分析方法,测定了国家一级地球化学标准物质中的痕量Au,Pt,Pd,测定值与标准值相吻合。

To prepare the Chinese Geology Resources Map, an ICP-MS method for the determination of ultra-trace amount of Au, Pd and Pt in exploration geochemical samples was developed. The sample was calcined at 600 degreesC for 2h then digested with aqua regia. The analytes in the digested solution were enriched by co-precipitating with Te and SnCl2. The separated precipitation was then dissolved in HNO3. The prepared sample solution was the nebulized together with the inner standard Tl solution via a three-way connection. MS Signals of (197)AU, Pd-108, Pt-195 and Tl-205 Were Measured. Contents of Au, Pd and Pt were determined via the calibration curves. Determination limits in terms of 6sigma were 0.23 ng.g(-1) for Au, 0.19 ng.g(-1) for Pt and 0.16 ng.g(-1) for Pd, respectively. The method has been verified with several National Certified Reference Materials with satisfied results.