Recent research findings show that precious metal minerals may be contained in black rock of different geological ages.However, the poor reproducibility of test results has affected geological research seriously.According to the component features of black rock samples, we improved the traditional nickel sulphide fire assay dispensation for measurement of platinum group elements.Covering agent with reducibility was added without Os isotope dilution.We chose proper assay reagents by experiments.The analysis process was as follow, firstly, dipping Ni obtained by melting in water directly and adding hydrochloric acid after powdering to make it decompose; then, filtering it with a ordinary funnel coated with a filter membrane; finally, dissolving the precipitate in aqua regia and starting ICP-MS determination with Lu as internal standard.In this article, 6 platinum group elements in black rock samples were determined with the method , and the results showed that the recovery rates of standard materials were between 85 ％ and 110 ％, and the relative standard deviation was less than 10 ％.The study illustrated that this method could meet the analysis requirements of platinum group elements in black rock samples.%近年来发现,不同地质时代的黑色岩系都可能含有贵金属矿物,但其分析测试结果的重现性很差,即"若有若无",严重影响地质研究工作的进展.根据黑色岩系样品的成分特征,对常规测定铂族元素的锍试金配方做了改进,增加了具有还原性的覆盖剂,且无需加入Os同位素稀释剂.通过实验选择了合适比例的试金配料,熔融后获得的镍扣直接用水浸泡粉化后加入盐酸分解,然后用贴有滤膜的普通漏斗过滤,再将滤膜包裹的沉淀用王水溶解后,用ICP-MS测定,Lu作内标.采用该方法对黑色岩系样品中6种铂族元素进行了测定,加入标准物质回收率为85%～110%,相对标准偏差小于10%,能够满足黑色岩系样品中6种铂族元素分析测试的要求.
展开▼
