Rapid and accurate determination of gold in geological materials by an improved ICP-MS method
Rapid and accurate determination of gold in geological materials by an improved ICP-MS method
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采用改进的 ICP-MS 方法快速准确地测定地质材料中的金
DOI：
10.1016/j.microc.2017.09.014
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发表时间：
2017-11-01
影响因子：
4.8
通讯作者：
Hu, Shenghong
中科院分区：
文献类型：
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作者：
Tao, Danyang;Guo, Wei;Hu, Shenghong
电感耦合等离子体质谱法（ICP-MS）准确测定地质样品中的金（Au）时，钽、铪氧化物干扰严重。建立了王水萃取-Ar气溶胶稀释ICP-MS测定地质样品中痕量Au的方法。在萃取过程中除去了超过95%的Hf和99.5%的Ta，并且通过在ICP等离子体之前向样品气溶胶中加入0.85 L min（-1）Ar成功地消除了残留的Ta或Hf氧化物。氧化物离子的干扰产率低至0.076%（TaO+/Fa（+））和0.021%（HfOH+/Hf+）。此外，为了进一步提高超痕量Au（低于ng g（-1））测定的信号背景比，将3 mL min（-1）CH 4加入ICP等离子体中，以提高Au的灵敏度（3.8倍）并降低背景信号（2.7倍）。所开发方法的定量限（LOQ 10 sigma）为0.014 ng g（-1）。用39种土壤、沉积物和岩石标准物质对该方法进行了评价，结果表明，所有标准物质的测定结果与标准值吻合较好。该方法可用于各种地质样品中痕量Au的测定。(C)2017爱思唯尔B. V.保留所有权利。
Accurate determination of gold (Au) in geological materials by inductively coupled plasma mass spectrometry (ICP-MS) is suffered to significant Ta and Hf oxide interferences. An improved method based on Ar aerosol dilution ICP-MS after aqua regia extraction was developed for the trace Au determination in geological samples. Over 95% of Hf and 99.5% Ta was removed in the extraction procedure, and the residual Ta or Hf oxides were successfully eliminated by adding 0.85 L min(-1) Ar to the sample aerosol prior to ICP plasma. The yields of interfering oxide ions were as low as 0.076% (TaO+/Fa(+)) and 0.021% (HfOH+/Hf+). In addition, to further improve the signal to background ratio for ultra-trace Au (sub ng g(-1)) determination, 3 mL min(-1) CH4 was added to ICP plasma for increasing the Au poor sensitivity (3.8-fold) and decreasing the background signal (2.7-fold). The limit of quantification (LOQ 10 sigma) for the developed method was 0.014 ng g(-1). This method was evaluated by 39 soils, sediments, and rock standard reference materials (SRMs) and the results of all SRMs were found to agree well with the certified values. It has potential as a routine method for the determination of trace levels of Au in various geological samples. (C) 2017 Elsevier B.V. All rights reserved.