Hf isotope ratio analysis using multi-collector inductively coupled plasma mass spectrometry: an evaluation of isobaric interference corrections
Hf isotope ratio analysis using multi-collector inductively coupled plasma mass spectrometry: an evaluation of isobaric interference corrections
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DOI：
10.1039/b206707b
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发表时间：
2002-01-01
影响因子：
3.4
通讯作者：
Burton, K
中科院分区：
文献类型：
--
作者：
Chu, NC;Taylor, RN;Burton, K
从Hf-Yb混合物的测量中，我们发现，涉及接受Yb同位素比和合理估计的质量偏差的同量异位素干扰的校正导致显着的校正不足的Hf-176，这是成比例的Yb的量添加。这可以解释为：（1）Hf和Yb之间的仪器质量偏差存在显著差异，以及（2）Yb和/或Hf系统中同位素比值的公认值不正确。我们已经评估了这些可能性，通过测量Yb和Hf的混合溶液中的两个MC-ICP-MS仪器，并进行了一系列的REE分馏实验，使用热电离质谱仪（TIMS）。我们的研究结果表明，目前接受的Yb同位素丰度是不合适的。我们提出了新的价值Yb同位素丰度的TIMS和MC-ICP-MS结果的基础上。使用新定义的Yb值，我们表明，Yb和Hf等离子体电离仪器中的质量偏差有相似的水平，Hf同位素比可以用来纠正Yb的质量偏差之前，随后校正的同量异位素干扰。Yb和Hf的激光烧蚀比较表明存在类似的关系，并且可以应用于化学分离不可能的微分析技术。
From measurements of Hf-Yb mixtures, we have found that the correction of isobaric interferences involving accepted Yb isotope ratios and reasonable estimates of mass bias result in a significantly under-corrected Hf-176, which is proportional to the amount of Yb added. This can be explained by (1) a significant difference in the instrumental mass bias between Hf and Yb, and (2) that the accepted values for isotopic ratios within the Yb and/or Hf systems are incorrect. We have evaluated these possibilities by measuring mixed solutions of Yb and Hf on two MC-ICP-MS instruments and undertaking a series of REE fractionation experiments using a thermal ionisation mass spectrometer (TIMS). Our results indicate that the presently accepted abundances of the Yb isotopes are not appropriate. We present new values for Yb isotopic abundances based on the TIMS and MC-ICP-MS results. Using the newly defined Yb values, we demonstrate that Yb and Hf have similar levels of mass bias in plasma ionisation instruments, and that Hf isotope ratios can be used to correct Yb mass bias before subsequent correction of isobaric interference. A laser ablation comparison of Yb and Hf indicates that similar relationships exist, and can be applied to micro-analytical techniques where chemical separation is not possible.