A rapid single column separation scheme for high-precision Sr–Nd–Pb isotopic analysis in geological samples using thermal ionization mass spectrometry
A rapid single column separation scheme for high-precision Sr–Nd–Pb isotopic analysis in geological samples using thermal ionization mass spectrometry
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DOI：
10.1039/c4ay02896a
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发表时间：
2015-05
影响因子：
3.1
通讯作者：
Chaofeng Li;Zhuyin Chu;Jing-hui Guo;You-Lian Li;Yue-heng Yang;Xianghui Li
中科院分区：
文献类型：
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作者：
Chaofeng Li;Zhuyin Chu;Jing-hui Guo;You-Lian Li;Yue-heng Yang;Xianghui Li
热电离质谱(TIMS)被认为是测定地质样品中锶、钕、铅同位素比值最准确的技术。然而，费时费力的样品分离过程极大地阻碍了仪器的测量效率。本研究建立了单岩溶蚀中锶-钕-铅的单柱分离化学法。该化学程序旨在最大限度地减少蒸发步骤的数量，并显著缩短分离时间，从而实现TIMS的高通量。与传统的三柱分离程序(∼3d)相比，该技术在分离时间(∼8h)方面具有高效率优势，分离效率提高了3倍。通过重复测定6个国际硅酸盐岩石标准物质的~(87)Sr/~(86)Sr、~(143)Nd/~(144)Nd、~(206)Pb/~(204)Pb、~(207)Pb/~(204)Pb和~(208)Pb/~(204)Pb比值，证明了该方法的稳定性。对这些标准的分析结果与已发表的数据吻合较好。Bcr-2标准样品的外部重现性(2RSD，n=10)分别为±0.0020%，±0.0023%，±0.0023%，206Pb/204Pb，207Pb/204Pb，208Pb/204Pb。
Thermal ionization mass spectrometry (TIMS) is considered the most accurate technique for determining Sr–Nd–Pb isotopic ratios in geological samples. However, time-consuming and complex sample separation procedures greatly hinder the instrumental measurement efficiency. In this study, a single-column separation chemistry procedure for Sr–Nd–Pb from single rock dissolution was developed. The chemistry procedure was designed to minimize the number of evaporation steps and considerably shorten the separation time, enabling high throughput for TIMS. In contrast to conventional three-column separation procedures (∼3 days), this technique was characterized by high efficiency superiority in terms of separation time (∼8 hours), a 3-fold enhancement in the separation efficiency. The stability of our procedure was demonstrated by replicated TIMS measurements of 87Sr/86Sr, 143Nd/144Nd, 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios for six international silicate rock reference materials, spanning a wide range of bulk compositions. The analytical results obtained for these standards agreed well with published data. The external reproducibility (2 RSD, n = 10) of a BCR-2 standard sample was ±0.0020% for 87Sr/86Sr, ±0.0023% for 143Nd/144Nd, and ±0.021–0.033% for 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios.