一次溶矿、两种方法联用测定地质样品中的金

主要研究了将氢醌容量法和原子吸收光谱法结合起来,实现一次溶矿,两种方法联用测定金含量。即在氢醌滴定基础上,王水氧化零价金,甲基异丁基酮(MIBK)萃取,火焰原子吸收法测定,准确检测出0.50g/t以下的低含量金。结果表明,方法简便、快速,不需二次溶矿。分析有证标准物质的结果与推荐值一致,样品加标回收率可达到96%以上,符合国家地质勘查管理规范的要求,精密度和准确度均能满足分析要求。适用于地质找矿中批量样品金的测定,已应用于实际样品分析,结果令人满意。

Determination of Gold in Geological Samples Using one Time Mineral Dissolution and Two Combined Methods

The focus of this paper is to establish an effective analytical method for gold determination using quinhydrone volumetric method and atomic absorption spectrometry, in which the minerals were needed to be dissolved only one time. On the basis of hydroquinone titration, the zero-valent gold was firstly oxidized by aqua regia, then extracted by methyl isobutyl ketone （MIBK） and finally detected by flame atomic absorption method. Less than 0.50 g/t of gold content can be accurately detected. The result shows that this method is simple and fast, without need for dissolving ore for the second time. The testing results for the certified reference materials were consistent with the certified values. Standard addition recovery rate can reach above 96%, which meets the requirement of the national geological exploration management specification. Both precision and accuracy can meet the analytical requirements. This method has been used in real sample analysis and the results are satisfactory, indicating that the method is suitable for the determination of gold in batch gold sample in geological prospecting.