锂同位素高精度测定进展、应用与发展趋势  

Advancements,Applications and Development Trends in High-Precision Lithium Isotope Analysis

作　　者：周晴 贺茂勇[1] 孔凡翠[3] 张西营[3] 程原原 饶辉辉 ZHOU Qing;HE Maoyong;KONG Fancui;ZHANG Xiying;CHENG Yuanyuan;RAO Huihui(State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an,710061,China;University of Chinese Academy of Sciences,Beijing,100049,China;Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining,810008,China)

机构地区：[1]中国科学院地球环境研究所,黄土与第四纪地质国家重点实验室,陕西西安710061 [2]中国科学院大学,北京100049 [3]中国科学院青海盐湖研究所,青海省盐湖地质与环境重点实验室,青海西宁810008

出　　处：《盐湖研究》2025年第1期1-17,共17页Journal of Salt Lake Research

基　　金：国家自然科学基金项目(42173023,42130206);陕西省杰出青年科学基金项目(2022JC-16);青海省盐湖地质与环境重点实验室奖励经费(2023)。

摘　　要：锂(Li)有两个稳定同位素,6Li和7Li。二者之间相对质量差较大,在自然界存在显著的同位素分馏,其同位素组成变化可为认识地球大气、海洋和上层地壳之间的地质过程和相互作用以及行星组成等提供重要证据,因此锂同位素作为灵敏的地球化学示踪剂广泛应用于化学、地质、海洋、生物和医学等研究领域。其同位素组成的高精度测定是一切研究的基础,近年来,由于锂同位素测定技术突破性进展和创新,大大提高了同位素测定的精度,推动和扩展了锂同位素的应用领域。文章对锂同位素组成测定主流方法、主要应用领域和未来挑战进行综述。测试方法主要包括:热电离质谱法(TIMS)、电感耦合等离子体质谱法(ICP-MS)、多接收电感耦合等离子质谱法(MC-ICP-MS)、二次离子质谱法(SIMS)、激光剥蚀多接收电感耦合等离子体质谱法(LA-MC-ICP-MS)和离子探针(SIMS)。这些测试方法分别面临不同的挑战:TIMS在分析过程中因热电离引起的同位素分馏,MC-ICP-MS难以降低质量歧视效应,而SIMS和LA-MC-ICP-MS分析过程中缺少标准样品、低含量样品精度有限及高含量样品重现性差等问题。同时对锂同位素在大陆风化、水环境、矿床学、碳酸盐pH计和行星科学领域的应用进行了简单介绍,最后对锂同位素测定中存在的问题和未来发展方向进行了综述,指出固体样品原位和单矿物分析将是未来锂同位素测试的发展方向。Lithium(Li)has two stable isotopes,6Li and 7Li,which exhibit large relative masses.As a result,there is notable isotopic fractionation in nature,and variations in isotopic composition provide important clues for understanding the geological processes and interactions between Earth’s atmosphere,oceans,and upper crust.Lithium isotopes,as sensitive geochemical tracers,are widely applied in various research fields,including chemistry,geology,oceanography,biology,and medicine.The accurate measurement of their isotopic composition forms the foundation for all such studies.In recent years,significant advancements and innovations in lithium isotope measurement techniques have greatly improved measurement precision.In this review,we discuss the mainstream methods for determining lithium isotopic composition,their major application areas,and future challenges.The testing methods include thermal ionization mass spectrometry(TIMS),inductively coupled plasma mass spectrometry(ICP-MS),multi-collector inductively coupled plasma mass spectrometry(MC-ICP-MS),laser ablation multi-collector inductively coupled plasma mass spectrometry(LA-MC-ICP-MS)and secondary ion mass spectrometry(SIMS).Each of these methods faces its own challenges:TIMS encounters difficulties in avoiding lithium isotope fractionation during the analysis process,MC-ICP-MS struggles with minimizing mass discrimination effects,while SIMS and LA-MC-ICP-MS encounter issues such as the lack of standard samples,limited precision for low-abundance samples,and poor reproducibility for high-abundance samples.This review introduces the applications of lithium isotopes in various fields,including continental weathering,water environment,mineralogy,carbonate pH and planetary.Finally,this review provides an overview of the challenges and future directions in lithium isotope measurement.Future developments in lithium isotope applications will focus on studying the isotopic composition of solid samples in situ measurements,and single mineral studies.

关 键 词：锂同位素 进展 高精度 

分 类 号：P597[天文地球—地球化学]