磁铁矿铁同位素标准物质的研制  

The preparation of reference material for Fe isotope measurement of magnetite samples

作　　者：李津[1] 唐索寒[1] 马健雄 朱祥坤[1] LI Jin;TANG Suo-han;MA Jian-xiong;ZHU Xiang-kun(MNR Key Laboratory of Isotope Geology,MNR Key Laboratory of Deep-Earth Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)

机构地区：[1]中国地质科学院地质研究所,自然资源部同位素地质重点实验室,自然资源部深地动力学重点实验室,北京100037

出　　处：《岩石矿物学杂志》2021年第3期535-541,共7页Acta Petrologica et Mineralogica

基　　金：国家重点研发计划(2019YFA0708400);中国地质科学院地质研究所基本科研业务费项目(J1716);国家自然科学基金面上项目(41973020,41873027)。

摘　　要：中国地质科学院地质研究所研制了磁铁矿铁同位素标准物质,将其命名为CAGS-MAG。研制过程中使用单因素方差分析法对CAGS-MAG进行均匀性检验,使用趋势检验对其在30个月中5次分析数据进行长期稳定性检验,结果显示均匀性和稳定性良好,满足标准物质的要求。CAGS-MAG的特征值采用多家实验室协作定值的方法确定。协作定值的单位包括中国地质科学院地质研究所、中国地质大学(北京)、中国科学技术大学、中国科学院广州地球化学研究所和天津大学。所有定值数据没有可疑值、符合正态分布且是等精度的,因此采用算术平均法确定标准物质的特征值。标准物质不确定度由定值过程引入的不确定度(u_(char))、均匀性引入的不确定度(u_(bb)或u_(bb)')和稳定性引入的不确定度分量(ults)共同确定。总不确定度为扩展不确定度,包含因子k=2。CAGS-MAG的特征值及不确定度为:δ^(56)Fe_(IRMM-014)(‰)=0.68±0.10,δ^(57)Fe_(IRMM-014)(‰)=0.99±0.13。该标准物质可用于磁铁矿和赤铁矿等铁矿样品的化学纯化效果的评价和验证、控制整个分析过程的质量以及实验室间的数据对比。A new magnetite reference material,named CAGS-MAG,was prepared by the Institute of Geology,Chinese Academy of Geological Sciences.One-way analysis of variance was used to test the homogeneity of CAGS-MAG,and trend analysis was used to test the stability of CAGS-MAG during 30 months(five times).CAGS-MAG showed sufficient homogeneity and stability for use as a Fe isotope reference material.The property value was determined by an interlaboratory comparison of results from five participating laboratories,which were Institute of Geology,Chinese Academy of Geological Sciences,University of Science and Technology of China,China University of Geosciences(Beijing),Tianjin University,and Guangzhou Institute of Geochemistry,Chinese Academy of Sciences.The property value was calculated from the unweighted means of the results submitted by the participating laboratories.Uncertainties were associated with batch characterization(uchar),possibility between-bottle variations(u_(bb)'),and those derived from effects related to long-term storage(ults).The property values[δ^(56)Fe_(IRMM-014)(‰)andδ^(57)Fe_(IRMM-014)(‰)]for CAGS-MAG are 0.68 and 0.99,with a combined expanded uncertainty(k=2)of 0.10 and 0.13 respectively.CAGS-MAG can be used to validate chromatographic separation and total measurement procedures and to conduct inter-laboratory comparisons when Fe isotopes of iron ore samples,such as hematite samples and magnetite samples,were measured.

关 键 词：磁铁矿 铁同位素 标准物质 特征值 不确定度 

分 类 号：P597.2[天文地球—地球化学]