Evaluation of Sr chemical purification technique for natural geological samples using common cation-exchange and Sr-specific extraction chromatographic resin prior to MC-ICP-MS or TIMS measurement
Evaluation of Sr chemical purification technique for natural geological samples using common cation-exchange and Sr-specific extraction chromatographic resin prior to MC-ICP-MS or TIMS measurement
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DOI：
10.1039/c2ja10333h
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发表时间：
2012-02
影响因子：
3.4
通讯作者：
Yue-heng Yang;Fu-Yuan Wu;Zhi‐Chao Liu;Zhuyin Chu;Liewen Xie;Jin-Hui Yang
中科院分区：
文献类型：
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作者：
Yue-heng Yang;Fu-Yuan Wu;Zhi‐Chao Liu;Zhuyin Chu;Liewen Xie;Jin-Hui Yang
在MC-ICP-MS或TIMS测量87Sr/86Sr比值之前，对天然地质样品进行了基于普通阳离子交换和sr特异性萃取色谱树脂的样品制备方案进行了评价和研究。在封闭容器中分别用HF、HNO3和HClO4对样品和实际地质样品进行酶解，然后依次进行化学纯化，然后用MC-ICP-MS或TIMS测定Sr同位素比值。由于使用普通阳离子交换树脂时，HREE存在于Sr组分中，因此这种纯化技术不适合在MC-ICP-MS分析之前进行，因为双重负载的HREE会干扰Sr质量。MC-ICP-MS同位素测定结果显示，放射性成因87Sr/86Sr比值与Sr组分中hree含量呈显著正相关，非放射性成因84Sr/86Sr或84Sr/88Sr比值与Sr组分中hree含量呈显著负相关。这种影响对于TIMS测量来说是微不足道的，因为电离温度通常较低，在分析过程中可以很好地控制。与传统的Sr纯化方法（阳离子交换树脂）相比，Sr特异性萃取色谱树脂可获得高纯度的Sr组分，适用于MC-ICP-MS和TIMS。
In this paper, sample preparation protocols based on common cation-exchange and Sr-specific extraction chromatographic resin were evaluated and investigated for natural geological samples prior to 87Sr/86Sr ratio measurement using MC-ICP-MS or TIMS. Several CRMs and real geological samples were digested using HF, HNO3 and HClO4 in closed vessels prior to sequential chemical purifications and then Sr isotopic ratios were determined by MC-ICP-MS or TIMS. Because HREEs reside in the Sr fraction when common cation-exhange resin is used, this purification technique is unsuitable prior to MC-ICP-MS analysis, as doubly loaded HREE interfere on Sr masses. We observe an obviously positive relationship between the radiogenic 87Sr/86Sr ratio and the content of HREEs in the Sr fractions, as well as a negative relationship between un-radiogenic 84Sr/86Sr or 84Sr/88Sr ratios and the content of HREEs in the Sr fractions during MC-ICP-MS Sr isotopic measurement. Such effects are insignificant for TIMS measurement, because ionization temperatures are generally lower and can be well controlled during the analyses. In contrast to the traditional Sr purification method (cation exchange resin), Sr-specific extraction chromatographic resin produces high purity Sr fractions, making it feasible for both MC-ICP-MS and TIMS.