电感耦合等离子体质谱法测定岩石中47种元素的不确定度评定

Uncertainty evaluation for the determination of 47 elements in rock by inductively coupled plasma mass spectrometry

采用封闭酸溶电感耦合等离子体质谱(ICP-MS)法测定岩石样品,分别对47种元素的测量结果不确定度进行评定。通过分析测试方法和测量条件,得到测量结果的不确定度主要由样品称量、样品溶液定容和样品溶液中元素浓度测量引入。在实验室质控条件下,对各不确定度分量进行评定和计算,其中随机因素导致的不确定度采用期间精密度试验综合评价,即采用A类方法评定。共完成了16个岩石国家标准物质(GBW 07103~GBW 07123)47种元素测量结果的不确定度合成,并参照GB/T 6379.2-2004,建立了含量w与扩展不确定度U之间的关系模型,运用这一关系模型可得到测量结果的不确定度估计值,只要测量过程本身或所使用的设备未变化,就不需要再重复进行不确定度评估。

A method was developed for the determination of rock by inductively coupled plasma mass spectrometry with pressurized acid digestion,and the uncertainty for the 47 elements determination were evaluated.Through the analysis of measurement method and condition,sample weighing,constant volume of sample solution and measurement of concentration were identified as the most important factors.The uncertainty components were evaluated and calculated under laboratory control conditions,the component which caused by random factors was evaluated by intermediate precision test with class A method.Finally,the composite uncertainty for the 47 elements determination of 16 national rock reference materials(GBW 07103-GBW 07123)was obtained,a relationship model between the content w and the expanded uncertainty U was established by consulting GB/T 6379.2-2004.With this model,the estimate of the uncertainty can be get,as long as the measuring process and equipment unchanged,no further evaluation is required.