Precise and accurate Ga isotope ratio measurements of geological samples by multi-collector inductively coupled plasma mass spectrometry  

作　　者：Yuxu Zhang Pan Qiao Chuanwei Zhu Haifeng Fan Hanjie Wen 

机构地区：[1]State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,99 West Lincheng Road,Guiyang 550081,Guizhou Province,China [2]School of Earth Sciences and Resources,Chang’an University,126 Yanta Road,Xi’an 710054,Shaanxi Province,China [3]College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 101408,China [4]College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Acta Geochimica》2024年第6期1054-1064,共11页地球化学学报（英文）

基　　金：the National Natural Science Foundation of China(Grant Nos.42273016 and 41573007);a special fund managed by the State Key Laboratory of Ore Deposit Geochemistry。

摘　　要：Gallium isotope is a potential geochemical tool for understanding planetary processes,environmental pollution,and ore deposit formation.The reported Ga isotope compositions(δ^(71)Ga NIST994 values)of some international geological standards,such as BCR-2 and BHVO-2 basalts,exhibit inconsistencies between diff erent laboratories.During mass spectrometry analysis,we found thatδ^(71)Ga NIST994 values of geological standards with or without the correction of the interference of^(138)Ba^(2+)(mass/charge ratio=69)on 69 Ga show signifi cant isotope off sets,and thus effi cient separation of Ba and correcting the interference of^(138)Ba^(2+)are both crucial to obtain accurateδ^(71)Ga values.By comparingδ^(71)Ga NIST994 values(relative to NIST SRM 994 Ga)of the same geostandards from diff erent laboratories,we suggest that the isotopic heterogeneity from NIST SRM 994 Ga is one of the key reasons for the inconsistencies inδ^(71)Ga NIST994 values of BCR-2 and BHVO-2.To facilitate inter-laboratory comparisons,we measured the Ga isotopic compositions of 11 geological reference materials(including Pb-Zn ore,bauxite,igneous rocks,and loess)and two Ga solution standards(NIST SRM 3119a and Alfa Aesar).Theδ^(71)Ga NIST994 andδ^(71)Ga IPGP values of these reference materials vary from 1.12‰to 2.63‰and−0.13‰to 1.38‰,respectively,and can be used to evaluate the precision and accuracy of Ga isotope data from diff erent laboratories.

关 键 词：Ga isotopes MC-ICP-MS Reference materials Chemical purification Ba interference 

分 类 号：P597[天文地球—地球化学]