The uncertainty budget of the multi-element analysis of glasses using LA-ICP-MS
The uncertainty budget of the multi-element analysis of glasses using LA-ICP-MS
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DOI：
10.1039/b608010c
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发表时间：
2007-01-01
影响因子：
3.4
通讯作者：
Liu, Xiao-Ming
中科院分区：
文献类型：
--
作者：
Luo, Yan;Gao, Shan;Liu, Xiao-Ming
根据EURACHEM/CITAC指南的“自下而上”方法，首次尝试估算了LA-ICPMS用于玻璃多元素分析的不确定度预算。(1)在常规条件下，使用193 nm准分子LA-ICPMS对NIST SRM612、614和USGS玻璃BCR-2G和BIR-1G进行了分析。使用NIST 610进行校准，并使用钙进行内部标准化。研究了分析物Co、La和Th的不确定度预算。(2)仪器漂移和NIST 610工作值的不确定度是NIST 612和BCR-2G/BIR-1G的典型个体分析的主要不确定度来源，Co、La和Th的质量含量在6至52微克(-1)范围内。相比之下，对于NIST614和BIR-1G，泊松计数统计的不确定度贡献占主导地位，这三个元素的较低范围在0.029到0.75µg g(-1)之间。洛杉矶是个例外。在所研究的所有质量含量范围内，其综合不确定度始终由NIST 610(2)工作值的不确定度主导，这表明需要为NIST 610(2)中的分析物以及所有具有较大不确定度的分析物提供更准确的参考值。此外，还使用与分析微探针地球化学实验室国际能力测试中使用的程序类似的程序进行了z分数评估。这项研究中的z分数在-2<；z<；2的范围内，表明在分析系统中没有显著的意外影响。这表明，此处报告的不确定性预算包含所有重要参数。
A first attempt was made to estimate an uncertainty budget for the multi-element analysis of glasses using LA-ICP-MS, in accordance with the "Bottom-up'' approach of the EURACHEM/CITAC-Guide.(1) Analyses of NIST SRM 612, 614 and USGS glasses BCR-2G and BIR-1G were carried out using a 193 nm excimer LA-ICP-MS under routine conditions. Calibration was performed using NIST 610 with internal standardisation using Ca. The uncertainty budgets for the analytes Co, La and Th were studied. Instrumental drift and uncertainties from working values of NIST 610, as reported by Pearce et al.,(2) are the dominant sources of uncertainty for a typical individual analysis of NIST 612 and BCR-2G/BIR-1G with mass contents of Co, La and Th ranging from 6 to 52 mu g g(-1). In contrast, the uncertainty contributions from Poisson counting statistics prevail for those of NIST 614 and BIR-1G with the three elements having a lower range between 0.029 and 0.75 mu g g(-1). La was an exception. Its combined uncertainties were consistently dominated by its uncertainty from the working value of NIST 610(2) at all mass content ranges investigated, suggesting that more accurate reference values for the analyte in NIST 610,(2) and for all analytes with large uncertainties, are needed. Additionally, a z-score assessment was carried out using procedures similar to those used in the International Proficiency Test for Analytical Microprobe Geochemistry Laboratories. The z-scores in this study were in the range -2 < z < 2, indicating that there were no significant unsuspected influences in the analytical system. This suggests that the uncertainty budget reported here contains all the significant parameters.