Pt-Re-Os同位素体系分析技术研究进展  

Progress in Pt-Re-Os isotope analytical techniques

作　　者：鲍厚银 李杰[1] BAO Houyin;LI Jie(State Key Laboratory of Isotope Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,Guangdong,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院广州地球化学研究所,同位素地球化学国家重点实验室,广东广州510640 [2]中国科学院大学,北京100049

出　　处：《地球化学》2024年第4期595-610,共16页Geochimica

基　　金：国家重点研发计划项目(2020YFA0714800)资助。

摘　　要：Pt-Os和Re-Os同位素体系(统称Pt-Re-Os同位素体系)在壳–幔和核–幔相互作用、矿床成因、陨石成因、太阳系早期演化等地球科学研究中具有重要应用潜力。由于地质样品中Pt-Re-Os含量极低(pg/g~ng/g级),对其元素含量和同位素组成进行高精度的分析测试极具挑战。本文对Pt-Re-Os同位素化学前处理和质谱测定方法研究进展进行综述。化学前处理方法包括酸溶法、碱熔法、火试金法、Carius管溶样法和HPA-S高温高压釜溶样法等常用的样品消解方法以及Pt-Re-Os的化学分离与纯化技术。重点介绍了负离子热电离质谱法(N-TIMS)和(多接收器)电感耦合等离子体质谱法(ICP-MS和MC-ICP-MS)测试Pt-Re-Os元素含量及同位素组成的原理、标准物质和测量精度,以及近年来高精度Os同位素质谱测定中O同位素校正、质量分馏校正、多原子干扰和提高灵敏度等质谱分析技术研究进展。与Re-Os同位素分析技术相比,Pt-Os同位素分析技术还存在困难,国内Pt-Os同位素分析技术仍处于起步阶段。本综述可为Pt-Re-Os同位素分析方法研究提供参考,从而推动国内Pt-Re-Os同位素地球化学研究的发展。Pt-Os and Re-Os isotope systems(collectively known as Pt-Re-Os isotope systems)have important applications in the study of the genesis of ore deposits,crust-mantle and core-mantle interactions,meteorite genesis,and the early evolution of the solar system.Due to the extremely low concentrations of Pt-Re-Os in geological samples(pg/g~ng/g),accurate and precise determination of their concentrations and isotopic compositions is challenging.This article summarizes progresses in Pt-Re-Os isotope analytical techniques including chemical preparation and mass spectrometry measurement.The chemical preparation procedures including digestion techniques(HF-HBr acid dissolution,alkali fusion,fire assay,Carius tube and HPA-S high temperature autoclave digestion method)and separation methods(Os distillation,solvent extraction,micro-distillation,and ion-exchange resin column)are reviewed.The accuracy and precision of the measurement of Pt-Re-Os isotope compositions by negative thermal ionization mass spectrometry(N-TIMS)and inductively coupled plasma mass spectrometry(ICP-MS and MC-ICP-MS)is introduced.This review focuses on the influencing factors(including oxygen and isobaric interference,mass fractionation correction and sensitivity)on accurate and precise measurement of Pt-Os isotope compositions by N-TIMS.Compared to Re-Os isotope analytical technology,the accurate and precise determination of Pt-Os isotope compositions is still difficult,and analytical methods are just starting to be be developed in China.We hope that this review can help develop analytical techniques for Pt-Re-Os isotope systems,and promote the application of Pt-Re-Os isotope geochemistry in earth sciences.

关 键 词：RE-OS同位素 Pt-Os同位素 消解 化学分离 质谱测量 

分 类 号：P597[天文地球—地球化学]