Abstract

Complete decomposition is an essential prerequisite for accurate trace element quantification in geological samples. This work presents a general high-pressure closed digestion approach for rock samples from basic to acidic rocks by inductively coupled plasma mass spectrometry. Using HNO₃−HF mixed system, different geological reference materials have been investigated for trace element determination, with acid ratio, decomposition time, digestion temperature, sample mass and reagent amount discussed in detail. In brief, 2.0 mL of HNO₃−HF with the ratio of 1 : 1 and a digestion time of 12 h at 185°C in high-pressure sealed bomb are optimal for 50 mg rock sample decomposition. With relative errors under 10%, the analytical results of W-2a, BCR-2, GSP-2, AGV-2 and GSR-1 agree well with certified values. This proposed high-pressure sealed digestion method is characterized with less acid consumption, complete digestion and less damage for digestion process, well meeting the requirements for large sample throughput in geological laboratory.

中文翻译：

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电感耦合等离子体质谱法测定岩石样品中一般高压封闭酸分解法

摘要

完全分解是对地质样品中痕量元素进行准确定量的必要先决条件。这项工作提出了一种通过感应耦合等离子体质谱法对从碱性岩石到酸性岩石的岩石样品进行常规高压封闭消解的方法。使用HNO ₃ -HF混合系统，已经研究了用于确定微量元素的不同地质参考物质，并详细讨论了酸比，分解时间，消化温度，样品质量和试剂量。简而言之，2.0 mL HNO ₃比例为1：1的-HF和在185°C高压密封炸弹中的12 h消解时间是50 mg岩石样品分解的最佳选择。当相对误差低于10％时，W-2a，BCR-2，GSP-2，AGV-2和GSR-1的分析结果与认证值非常吻合。提出的高压密封消解方法具有酸耗少，消解彻底，消解过程破坏小等特点，很好地满足了地质实验室对大样品通量的要求。