Precise measurements of trace neodymium isotopes as Nd ions by thermal ionization mass spectrometry using film porous ion emitters
Precise measurements of trace neodymium isotopes as Nd ions by thermal ionization mass spectrometry using film porous ion emitters
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使用薄膜多孔离子发射器通过热电离质谱法精确测量 Nd 离子形式的痕量钕同位素
DOI：
10.1016/j.sab.2019.105656
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Hao Fanhua
中科院分区：
文献类型：
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作者：
Shao Xuepeng;Bu Wenting;Long Kaiming;Tang Lei;Liu Xuemei;Yan Heng;Hao Fanhua
Nd+离子的钕同位素分析比NdO+离子更有利，因为潜在的同量异位素干扰较小，并且不需要复杂的氧同位素校正。但其灵敏度低、重现性差等缺点严重阻碍了其应用。本文首次提出了一种利用薄膜多孔离子发射体（FPIE）结合简化的Nd化学分离过程精确测量143 Nd/144 Nd比值的热电离质谱（TIMS）分析方法。Nd+离子产额比传统的Nd+离子分析方法高一个数量级。重复测量参比物质JNdi-1（1 ng）得到的143 Nd/144 Nd值为0.512113 ± 33（2SD，n= 9）。所达到的外部精度满足核取证应用的要求。对岩石粉末标准物质和铀矿石样品进行了分析，进一步检验了方法的准确性和重现性。认为该方法不仅具有独特的核法医学应用价值，而且可以拓展Nd同位素比值分析在地球化学、地质年代学和环境科学中的应用。
Neodymium isotope analysis as Nd+ions is more favored than as NdO+ions due to less potential isobaric interferences and no need for complicated oxygen isotope corrections. However, the poor sensitivity and inadequate reproducibility seriously hinder its application. In this study, a new analytical method by thermal ionization mass spectrometry (TIMS) is initially presented for the precise measurement of143Nd/144Nd ratio as Nd+ions with film porous ion emitter (FPIE), combined with a simplified Nd chemical separation procedure. The Nd+ion yields were one order of magnitude higher than those of traditional Nd+ion analysis method. Repeated measurements of reference material JNdi-1 (1 ng) yielded a143Nd/144Nd value of 0.512113 ± 33 (2SD,n= 9). The achieved external precisions fulfilled the requirements for applications in nuclear forensics. Rock powder reference materials and uranium ore samples were analyzed to further test the accuracy and reproducibility of our method. We believe that this method is not only a particular value for nuclear forensic purposes, but also can expand the applications of Nd isotope ratio analysis in geochemistry, geochronology and environmental sciences.