离子探针Li同位素微区原位分析技术与应用  

In situ Li isotopic microanalysis using SIMS and its applications

作　　者：李献华[1] 刘宇[1] 汤艳杰[1] 高钰涯[1] 李秋立[1] 唐国强[1] 

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室,北京100029

出　　处：《地学前缘》2015年第5期160-170,共11页Earth Science Frontiers

基　　金：国家自然科学基金面上项目(41173010;41173009)

摘　　要：Li同位素是一种新兴的非传统稳定同位素示踪工具,其应用领域涵盖了从地表到地幔的熔/流体与矿物之间的相互作用以及行星的早期演化研究。随着多接收器电感耦合等离子体质谱仪(MC-ICPMS)和二次离子质谱仪(SIMS)技术的迅速发展,锂同位素地球化学研究取得了长足进步和发展。Cameca IMS 1280SIMS可以在约20μm×30μm×2μm的空间尺度上获得约1‰(1σ)的分析精度,实现了高精度微区原位Li同位素分析。由于Li同位素基体效应明显,获取与分析样品基体匹配的标准样品对Li同位素分析的准确性尤为关键。在重点介绍SIMS微区原位Li同位素分析技术的基础上,以锆石、橄榄石和辉石为例,综述了Li同位素原位分析技术的最新应用研究进展及存在的问题,旨在加深对Li同位素原位分析技术的理解,展示其在地球化学研究中的良好应用前景。Lithium isotopes are one of the newly developed non-traditional stable isotope tracers. This isotopic system has been gaining increasing interest in fingerprinting geochemical processes, in particular, the interaction between mineral and fluids from the surface to mantle as well as the early evolution of Earth and other planets. With rapid development of MC-ICPMS and SIMS techniques, Li isotope geochemistry has made considerable progress and development. Cameca IMS 1280 SIMS is designed to undertake in situ isotopic microanalysis at relatively high-precision （-1‰, 1σ） and ultra-high spatial resolution - 20 × 30 × 2 μm^3. Matrix-matched reference materials are crucial for accurate SIMS Li isotope measurement due to the substantial matrix effects. On the basis of a review of current state of in-situ SIMS Li isotope analytical technique, we present representative applications as well as possible limitations of SIMS Li isotope investigations of zircon, olivine and pyroxene. The aim of the paper is to improve our understanding and application of Li isotopes in future research.

关 键 词：Li同位素 离子探针 基体效应 同位素分馏 

分 类 号：P597.2[天文地球—地球化学]