Low-memory, small sample size, accurate and high-precision determinations of lithium isotopic ratios in natural materials by MC-ICP-MS
Low-memory, small sample size, accurate and high-precision determinations of lithium isotopic ratios in natural materials by MC-ICP-MS
复制标题
DOI：
10.1039/b926327f
复制
发表时间：
2010-01-01
影响因子：
3.4
通讯作者：
Chung, Chuan-Hsiung
中科院分区：
文献类型：
--
作者：
Huang, Kuo-Fang;You, Chen-Feng;Chung, Chuan-Hsiung
本文报道了一种相对简单、快速、高精密度和准确度的MC-ICP-MS测定锂同位素比值的方法。与已发表的方法相比，我们的MC-ICP-MS技术使用了低记忆APEX-IR去溶剂化器和高灵敏度的X-skimmer锥，以及简单的一步柱分离，目的：为天然样品中低Li含量的Li同位素测定提供一个最佳条件。通过分析一系列经过认证的标准物质，这些标准物质涵盖了广泛的δ Li-7，并涵盖了不同的样品基质，为未来的工作提供了有用的基准，从而验证了这种新方法。基于这种方法，与其他方法相比，Δ Li-7（+/- 0.12份/千份，2SD，n = 46）的长期精度显著提高了2倍，具有需要相当小尺寸的ca的额外优点。1.2吴莉。测定了几种参比标准品的Δ Li-7，包括Li 2CO 3（IRMM-016：千分之0.05），海水（采购处：千分之30.84;国家统计局-5：千分之30.72），沿海沃茨（卡斯-4：千分之30.69; SLEW-3：千分之30.45），河水（NIST SRM 1640：9.36 ppm），珊瑚标准（JCp-1：20.16份/千）和两种硅酸盐岩石（AGV-2：7.98份/千和BHVO-2：4.63份/千）。应用改进的技术，我们能够产生准确和高精度的低[Li]天然物质，如大陆径流和海洋生物碳酸盐的δ Li-7数据，这可以提供有价值的信息大陆风化过程和古海洋学意义。
Here we report a comparatively simple, rapid, high-precision and accurate technique for the Li isotope ratio determination by MC-ICP-MS. In comparison with published methods, our MC-ICP-MS technique uses a low-memory APEX-IR desolvator and a high-sensitivity X-skimmer cone, together with a simple one-step column separation, to achieve an optimal condition for Li isotope determination in natural materials with different matrices at low levels of Li. This new method was validated by analyzing a series of certified reference materials, which span a wide range of delta Li-7 and cover different sample matrices in order to provide a useful benchmark for future works. On the basis of this approach, the long-term precision of delta Li-7 (+/- 0.12 parts per thousand, 2SD, n = 46) was significantly improved by a factor of 2 compared to other methods, with the additional advantage of requiring a rather small size of ca. 1.2 ng Li. The delta Li-7 for several reference standards were determined, including Li2CO3 (IRMM-016: 0.05 parts per thousand), seawater (IAPSO: 30.84 parts per thousand; NASS-5: 30.72 parts per thousand), coastal waters (CASS-4: 30.69 parts per thousand; SLEW-3: 30.45 parts per thousand), river water (NIST SRM 1640: 9.36 parts per thousand), coral standard (JCp-1: 20.16 parts per thousand) and two silicate rocks (AGV-2: 7.98 parts per thousand and BHVO-2: 4.63 parts per thousand). Applying the improved technique, we are able to produce accurate and high-precision delta Li-7 data for low [Li] natural materials, such as continental runoffs and marine biogenic carbonates, which can provide valuable information on continental weathering processes and paleoceanographic implications.