CGSG系列标准物质元素分馏效应及主量微量元素单元内均匀性探究

Study on the Elemental Fractionation Effect of CGSG Reference Materials and the Related Within-Unit Homogeneity of Major and Trace Elements

探究CGSG系列标准物质(CGSG-1、CGSG-2、CGSG-4、CGSG-5)的元素分馏效应及均匀性问题有助于开展其质量评估和应用推广。本文采用电子探针(EMPA)和激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)研究了CGSG标准物质中的元素分馏效应、主量和微量元素单元内均匀性,并报道了主量和微量元素分析数据。结果表明,在50μm激光束斑下,CGSG系列标准物质的元素分馏效应可忽略不计。EMPA均匀性指数结果显示,CGSG标准物质主量元素的单元内均匀性满足要求;以MPI-DING标准物质为参照,LA-ICP-MS测试CGSG标准物质中的大多数微量元素的单元内均匀性良好。与已报道的数据相比,本文报道的EMPA主量元素数据偏差在2%以内;LA-ICP-MS主量元素数据偏差在5%以内,微量元素数据基本匹配,少数元素由于分析不确定度较大等原因,如Cr、Ge、Cd、As、Tl等与已报道数据偏差较大。总体上,本文报道的分析数据可为CGSG定值数据库提供进一步的补充。

Studies on elemental fractionation and homogeneity of CGSG reference materials（ CGSG- 1,CGSG- 2,CGSG- 4 and CGSG- 5） promote quality assessment and application. The elemental fractionation and within-unit homogeneity of CGSG reference materials were evaluated using Electron Microprobe and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry（ LA-ICP-MS）. Meanwhile,the major and trace element contents were also reported. The results showed that the elemental fractionation of CGSG reference materials was negligible for 50 μm spot size. Electron Microprobe homogeneity index illustrated that the homogeneity of major elements in CGSG reference materials is approvingly acceptable,and most trace elements possess same homogeneity grade with MPI-DING reference materials. Analytical results of major elements by Electron Microprobe and LA-ICP-MS are consistent with published data within 2% and 5% errors,respectively. Analytical results of trace elements by LA-ICP-MS are generally in agreement with the published data. Some elements such as Cr,Ge,Cd,As and Tl show a larger deviation due to the large uncertainties of the analytical technique. In general,the analysis data reported here could supplement the CGSG value database.