High‐Precision Fe and Mg Isotope Ratios of Silicate Reference Glasses Determined In Situ by Femtosecond LA‐MC‐ICP‐MS and by Solution Nebulisation MC‐ICP‐MS
High‐Precision Fe and Mg Isotope Ratios of Silicate Reference Glasses Determined In Situ by Femtosecond LA‐MC‐ICP‐MS and by Solution Nebulisation MC‐ICP‐MS
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DOI：
10.1111/j.1751-908x.2014.00288.x
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发表时间：
2014-09
影响因子：
3.8
通讯作者：
Martin Oeser;S. Weyer;I. Horn;S. Schuth
中科院分区：
文献类型：
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作者：
Martin Oeser;S. Weyer;I. Horn;S. Schuth
在这项研究中，开发了一种通过飞秒激光消融多收集器ICP-MS（fs-LA-MC-ICP-MS）进行高精度原位Fe和Mg同位素测定的技术。该技术被用来确定一系列常见的参考玻璃的参考值，这些参考玻璃可用于硅酸盐中原位Fe和Mg同位素测定的外部标准化。分析的玻璃是MPI‐DING和美国地质调查局（USGS）参考玻璃系列的一部分，由玄武岩（BIR‐1G，BCR‐2G，BHVO‐2G，KL 2 ‐G，ML 3B ‐G）和科马提岩（K128 ‐G和K132 ‐G）组成。通过原位fs-LA-MC-ICP-MS和常规溶液雾化多收集器ICP-MS测定其Fe和Mg同位素组成。我们测定了这些玻璃的δ 56 Fe值在-0.04 ‰和0.10‰之间（相对于IRMM-014），δ 26 Mg值在-0.40 ‰和-0.15 ‰之间（相对于DSM-3）。我们的Fe和Mg同位素组成的fs-LA-MC-ICP-MS结果在分析不确定性范围内与溶液雾化分析一致。此外，三种USGS参比玻璃（BIR-1G、BHVO-2G和BCR-2G）的结果与相同参比材料的粉末和溶解等分试样的先前结果一致。现场测定δ 56 Fe和δ 26 Mg值的测量重现性通常分别优于0.12‰和0.13‰（2s）。我们进一步证明，我们的技术是一个合适的工具，以解决化学分区橄榄石晶体中的同位素分区。它可以用于同位素分区矿物的各种不同应用，例如，在岩浆或变质岩或陨石中，以解开它们的形成或冷却速率。
In this study, a technique for high precision in situ Fe and Mg isotope determinations by femtosecond‐laser ablation‐multi collector‐ICP‐MS (fs‐LA‐MC‐ICP‐MS) was developed. This technique was employed to determine reference values for a series of common reference glasses that may be used for external standardisation of in situ Fe and Mg isotope determinations in silicates. The analysed glasses are part of the MPI‐DING and United States Geological Survey (USGS) reference glass series, consisting of basaltic (BIR‐1G, BCR‐2G, BHVO‐2G, KL2‐G, ML3B‐G) and komatiitic (GOR128‐G and GOR132‐G) compositions. Their Fe and Mg isotope compositions were determined by in situ fs‐LA‐MC‐ICP‐MS and by conventional solution nebulisation multi‐collector ICP‐MS. We determined δ56Fe values for these glasses ranging between ‐0.04‰ and 0.10‰ (relative to IRMM‐014) and δ26Mg values ranging between ‐0.40‰ and ‐0.15‰ (relative to DSM‐3). Our fs‐LA‐MC‐ICP‐MS results for both Fe and Mg isotope compositions agreed with solution nebulisation analyses within analytical uncertainties. Furthermore, the results of three USGS reference glasses (BIR‐1G, BHVO‐2G and BCR‐2G) agreed with previous results for powdered and dissolved aliquots of the same reference materials. Measurement reproducibilities of the in situ determinations of δ56Fe and δ26Mg values were usually better than 0.12‰ and 0.13‰ (2s), respectively. We further demonstrate that our technique is a suitable tool to resolve isotopic zoning in chemically‐zoned olivine crystals. It may be used for a variety of different applications on isotopically‐zoned minerals, e.g., in magmatic or metamorphic rocks or meteorites, to unravel their formation or cooling rates.