A Fast Separation Method for Isotope Analysis Based on Compressed Nitrogen Gas and Ion-Exchange Chromatography Technique—A Case Study of Sr-Nd Isotope Measurement
A Fast Separation Method for Isotope Analysis Based on Compressed Nitrogen Gas and Ion-Exchange Chromatography Technique—A Case Study of Sr-Nd Isotope Measurement
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DOI：
10.1007/s12583-017-0944-0
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发表时间：
2018-02
影响因子：
3.3
通讯作者：
Honglin Yuan;X. Liu;Z. Bao;Kaiyun Chen;C. Zong
中科院分区：
文献类型：
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作者：
Honglin Yuan;X. Liu;Z. Bao;Kaiyun Chen;C. Zong
在离子交换树脂的离子净化过程中，采用高纯氮气提高移动的相流速。这是为了提高同位素分离和纯化的效率，并满足快速多收集器电感耦合等离子体质谱（MC-ICPMS）分析的效率要求。对于Cu同位素分离，当气体流速>60 mL/min时，分离色谱峰变宽，回收率下降到<99.2%。另一方面，在20 mL/min的气体流速下未观察到Cu峰的显著变化，并且确定回收率> 99.9%。通过标准样品交叉法测量的Cu同位素比与参考数据在±2 SD误差范围内一致。分离时间从传统的10 h（无N2）缩短到4 h（有N2），效率提高了一倍多。此外，在AGV-2（美国地质调查局安山岩标准样品）中，以20 mL/min的气体流量加速Sr和Nd同位素分离，表明随着N2的通过，纯化的液体包含Rb/Sr和Sm/Nd比分别<0.000 049和<0.000 001 5。这表明Rb与Sr和Sm与Nd的有效分离。因此，MC-ICPMS可用于准确测定Sr和Nd同位素比值。所得结果与参考数据在± 2SD误差范围内一致，总分离时间由2d缩短至<10 h。
High-purity N2was used to increase the mobile phase flow rate during ion purification of ion-exchange resin. This was performed to improve the efficiency of isotope separation and purification, and to meet the efficiency requirements of rapid multiple-collector-inductively coupled plasma mass spectrometry (MC-ICPMS) analysis. For Cu isotope separation, our results indicated that at a gas flow rate >60 mL/min, the separation chromatographic peaks broadened and the recovery rate decreased to <99.2%. On the other hand, no significant change in the Cu peaks was observed at a gas flow rate of 20 mL/min and the recovery rate was determined to be >99.9%. The Cu isotope ratio, measured by the standard-sample bracketing method, agreed with reference data within a ±2 SD error range. The separation time was reduced from the traditional 10 h (without N2) to 4 h (with N2), indicating that the efficiency was more than doubled. Moreover, Sr and Nd isotope separation in AGV-2 (US Geological Survey andesite standard sample) accelerated with a 20 mL/min gas flow, demonstrating that with the passage of N2, the purified liquid comprised Rb/Sr and Sm/Nd ratios of <0.000 049 and <0.000 001 5, respectively. This indicated an effective separation of Rb from Sr and Sm from Nd. MC-ICPMS could therefore be applied to accurately determine Sr and Nd isotope ratios. The results afforded were consistent with the reference data within a ±2 SD error range and the total separation time was shortened from 2 d to <10 h.