混酸分解-电感耦合等离子体质谱（ICP-MS）法测定地质样品中铌钽锂铍铷钨

地质样品中的铌、钽、锂、铍、铷、钨元素含量相差大，且同一样品中各元素含量差异也较大。如在原矿中的含量只有几十至几百μg/g，而在精矿中的含量则达到了百分之几至百分之几十，高含量样品中的铌钽元素在强酸性溶液中不稳定，极易水解，准确测定这些元素需要多种方法，分析过程繁琐。传统的分析方法过程复杂、难以实现同时测定多种元素。通过考察分解体系酸的用量选择、提取剂的选择、提取剂用量的选择、测定内标元素的选择，建立了混酸分解-电感耦合等离子体质谱法同时测定地质样品中铌、钽、锂、铍、铷、钨元素的测定方法。本文采用氢氟酸-硝酸-盐酸-高氯酸-硫酸分解样品，用3～4滴氢氟酸+ 5 %硫酸+ 5 %过氧化氢萃取体系代替常规有机酸(酒石酸等。)萃取体系。采用ICP -MS同时测定各含量段地质中铌、钽、锂、铍、铷、钨的不同含量。采用该方法测定国家一级标准物质 GBW07155、GBW07153 、GBW07185，结果表明，各元素的检测结果与认定值无显著性误差,精密度RSD（n=6）0.45%～4.05%,准确度?lgC （n=6）在-0.008%～0.009%之间,适用于地质样品中的铌、钽、锂、铍、铷、钨元素的测定。

Determination of niobium, tantalum, lithium, beryllium, rubidium and tungsten in geological samples by mixed acid decomposition-inductively coupled plasma mass spectrometry ( ICP-MS )

The contents of niobium, tantalum, lithium, beryllium, rubidium and tungsten in geological samples are quite different, and the contents of each element in the same sample are also quite different. For example, the content in the raw ore is only tens to hundreds of μg / g, while the content in the concentrate reaches several percent to tens of percent. The niobium and tantalum elements in the high content samples are unstable in the strong acidic solution and are easily hydrolyzed. Accurate determination of these elements requires a variety of methods, and the analysis process is cumbersome. Traditional analytical methods are complex and difficult to simultaneously determine multiple elements. A method for the simultaneous determination of niobium, tantalum, lithium, beryllium, rubidium and tungsten in geological samples by mixed acid decomposition-inductively coupled plasma mass spectrometry was established by investigating the selection of the amount of acid in the decomposition system, the selection of extractant, the selection of extractant and the selection of internal standard elements. In this paper, hydrofluoric acid-nitric acid-hydrochloric acid-perchloric acid-sulfuric acid was used to decompose the sample, and 3 ~ 4 drops of hydrofluoric acid + 5 % sulfuric acid + 5 % hydrogen peroxide extraction system was used to replace conventional organic acids ( tartaric acid, etc. ). ) Extraction system. ICP-MS was used to simultaneously determine the different contents of niobium, tantalum, lithium, beryllium, rubidium and tungsten in each content section. The national primary standard materials GBW07155, GBW07153 and GBW07185 were determined by this method. The results showed that there was no significant error between the test results and the certified values of each element. The precision RSD ( n = 6 ) was 0.45 % -4.05 %, and the accuracy ? lgC ( n = 6 ) was between-0.008 % and 0.009 %, which was suitable for the determination of niobium, tantalum, lithium, beryllium, rubidium and tungsten in geological samples.