用热电离质谱法对大型石样本 (>1 g) 进行高精度的Sm同位素分析
Paul Frossard1, James M J Ball1, Maria Schönbächler1
1Institute for Geochemistry and Petrology, ETH Zürich Zürich Switzerland paul.frossard@eaps.ethz.ch.
Journal of analytical atomic spectrometry
|December 2, 2024
概括
这项研究引入了一种新的高精度Sm同位素分析方法,使用热电离质谱法 (TIMS). 多态方法显著提高了稀缺的144Sm同位素的精度,这对地质和核合成研究至关重要.
科学领域:
- 地质化学 地质化学
- 同位素地球化学 同位素地球化学
- 分析化学 分析化学
背景情况:
- 精确的Sm同位素分析对于理解地质过程和核合成变异至关重要.
- 现有的方法在实现高精度方面面临挑战,特别是对于稀缺的同位素,如144Sm.
- 准确的同位素测量需要强大的化学分离和优化的质谱技术.
研究的目的:
- 开发和验证使用热电离质谱法 (TIMS) 的新型高精度Sm同位素分析方法.
- 提高Sm同位素测量的精度,特别关注低丰度的144Sm同位素.
- 建立一种可靠的方法来分析地质样本,并根据已知的标准验证结果.
主要方法:
- 一个四步化学分离方案,涉及离子交换和液液提取 (TRU-Spec,DGA) 用于Sm和Nd的隔离.
- 优化热电离质谱仪 (TIMS) 分析设置,包括光纤组件和电离激活器.
- 测试用于确定Sm同位素比率的静态,多静态和动态测量方法,并将其规范化为147Sm/152Sm和152Sm/148Sm.
主要成果:
- 开发的方法可以从地质样本中清晰地分离Sm和Nd.
- 多静态TIMS方法显著提高了144Sm/152Sm比率的精度,达到13-22ppm (2 SD).
- 获得的高精度Sm同位素值与陆地岩石标准和石Allende的文献数据一致.
结论:
- 新的四步化学分离和多态TIMS方法为地质样品提供了高精度的Sm同位素分析.
- 这种方法提高了稀缺的Sm同位素的精度,使核合成同位素变异的研究更准确.
- 经过验证的程序为地球化学研究和外星材料的表征提供了一个可靠的工具.
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