High-yield lithium separation and the precise isotopic analysis for natural rock and aqueous samples
High-yield lithium separation and the precise isotopic analysis for natural rock and aqueous samples
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DOI：
10.1016/s0009-2541(97)00163-0
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发表时间：
1998-03
期刊：
影响因子：
3.9
通讯作者：
T. Moriguti;Eizo Nakamura
中科院分区：
文献类型：
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作者：
T. Moriguti;Eizo Nakamura
建立了岩石和水样的高产率锂分离技术，并用热电离质谱进行了高精度的锂同位素分析。使用有机离子交换树脂进行了四个不同阶段的离子交换层析。在第三柱状态下，用乙醇-盐酸溶液完全分离了锂和钠。对于岩石样品和海水，整个化学过程的总试剂用量分别减少到42ml和33.3ml。回收率为99.2-99.3%，总程序空白为11pg。采用Li3PO4作为离子源材料进行了质谱分析。7Li/6Li比值的批内精密度和重现性：岩石为±0.04~0.07‰(2σ均值)和0.37‰(相对标准偏差)；海水为±0.05~0.08‰(2σ均值)和0.35‰(相对标准偏差)。在这种方法中，Rb、Sr、Sm、Nd、La和Ce可以在第一层析锂洗脱后被收集，然后通过以下特定的步骤进行分离。因此，该方法可以对陨石、地幔物质等少量贫锂和受限样品进行多同位素分析，从而扩展到锂同位素地球化学和宇宙化学。
A high-yield lithium separation technique for rock and aqueous samples has been established together with precise Li isotope analysis by thermal ionization mass spectrometry. Four separate stages of ion-exchange chromatography were carried out using organic ion-exchange resin. An ethanol-HCl solution was used for complete separation of Li from Na at the third column state. Total reagent volume for the entire chemical process was reduced to 42 ml and 33.3 ml for rock samples and seawater, respectively. The recovery yield and total procedural blank are 99.2–99.3% and 11 pg, respectively. Li3PO4was used as an ion-source material in the mass spectrometric analysis. The in-run precision and reproducibility of measured7Li/6Li ratios were ±0.04–0.07‰ (2σmean) and 0.37‰ (relative standard deviation; RSD) for rock and ±0.05-0.08‰ (2σmean) and 0.35‰ (RSD) for seawater. In this method, Rb, Sr, Sm, Nd, La and Ce can be collected after Li elution in the first column chromatography, then separated by the following specific procedures for these elements. Therefore, this method makes possible multi-isotope analysis for Li-poor and restricted small amounts of samples such as meteorites and mantle materials, extending to Li isotope geochemistry and cosmochemistry.