Sequential Chemical Separation of Cr and Ti from a Single Digest for High‐Precision Isotope Measurements of Planetary Materials
Sequential Chemical Separation of Cr and Ti from a Single Digest for High‐Precision Isotope Measurements of Planetary Materials
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从一次消解中连续化学分离 Cr 和 Ti，用于行星材料的高精度同位素测量
DOI：
10.1111/ggr.12249
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发表时间：
2018
影响因子：
3.8
通讯作者：
Yamakawa Akane
中科院分区：
文献类型：
--
作者：
Hibiya Yuki;Iizuka Tsuyoshi;Yamashita Katsuyuki;Yoneda Shigekazu;Yamakawa Akane
行星物质的Cr和Ti同位素联合测定为研究它们的成因关系和原行星盘的演化提供了一种手段。在这里，我们报告了新的顺序化学分离程序相结合的铬和钛同位素比测量。它包括三个步骤：（a）使用AG 1-X8阴离子交换树脂去除Fe，（B）使用TODGA树脂分离Ti和（c）使用AG 50 W-X8阳离子交换树脂分离Cr（对于具有高Cr/Ti和Ca/Ti比的样品，使用AG 1-X8阴离子交换树脂进行一个额外的Ti纯化步骤）。我们提出的程序应用于陆地和陨石样品与各种成分。采用3-5 ng和2-3 ng的总手术Cr和Ti空白，实现了90-100%的典型回收率。我们分别使用热电离质谱法和多收集器电感耦合等离子体质谱法测量了分离样品的Cr和Ti同位素组成。我们的铬和钛同位素数据被发现是一致的，与以前的研究个别铬和钛同位素组成的陨石。这些结果证明了我们的分离方法在应用于行星材料的单颗恒星的高精度Cr和Ti同位素分析时的能力。
Combined determination of Cr and Ti isotopes of planetary materials offers a means with which to investigate their genetic relationship and the evolution of the protoplanetary disk. Here, we report the new sequential chemical separation procedure for combined Cr and Ti isotope ratio measurements. It comprises three steps: (a) Fe removal using AG1‐X8 anion exchange resin, (b) Ti separation using TODGA resin and (c) Cr separation using AG50W‐X8 cation exchange resin (with one additional step of Ti purification using AG1‐X8 anion exchange resin for samples having high Cr/Ti and Ca/Ti ratios). We applied the proposed procedure to terrestrial and meteorite samples with various compositions. Typical recovery rates of 90–100% were achieved with total procedural Cr and Ti blanks of 3–5 and 2–3 ng, respectively. We measured the Cr and Ti isotope compositions of the separated samples using thermal ionisation mass spectrometry and multiple collector‐inductively coupled plasma‐mass spectrometry, respectively. Our Cr and Ti isotope data were found to be consistent with those of previous studies of individual Cr and Ti isotopic compositions of the meteorites. These results demonstrate the capability of our separation method when applied to combined high‐precision Cr and Ti isotope analyses for single digests of planetary materials.