摘要
在用高精度分析方法经检验证明样品均匀性和稳定性良好的条件下 ,可以以定值测试的不确定度表示标准物质标准值的不确定度。在较全面分析了地球化学标准物质定值测试的误差后 ,提出以测试结果平均值的标准偏差算得A类不确定度、以定值方法间的偏倚估计B类不确定度 ,以两者的合成值作为地球化学标准物质不确定度的估计值 ,并用其试算了部分已有地球化学标准物质有代表性元素的不确定度 ,结果表明提出的不确定度估算方法是可信的。
Uncertainty of certified values is a key problem in preparation and application of certifed reference materials(CRMs). Because certification of geochemical CRMs is complex and the measurements could not be continuously traced back, a common understanding of estimating the uncertainty of the certified value is not reached. At present, standard deviation and data set given are only taken as reference on estimating the uncertainty in certification of CRMs. Under the condition of good homogeneity and stability of samples proved by analysis with high precision analytical methods, the uncertainty of the certification analysis can be regarded as the uncertainty of the certified value of CRMs. Based on a comprehensive analysis for the errors in certification analysis for geochemical CRMs, two terms are proposed. One is “A type uncertainty” which is calculated from the standard deviation of mean values of analysis. The other is “B type uncertainty” which is from the estimation of the bias caused by different analytical methods used in the certification. A comprehensive uncertainty value from these two types of uncertainties is taken as a estimating uncertainty of certifed values for geochemical CRMs. The method proposed has been applied to the calculation of the uncertainties for some representative elements in geochemical CRMs with satisfactory results.
出处
《岩矿测试》
CAS
CSCD
北大核心
2001年第4期287-293,共7页
Rock and Mineral Analysis
