X射线荧光光谱法测定元素含量的不确定度近似评估

来源期刊：冶金分析2010年第9期

论文作者：洪俊辉

文章页码：77 - 80

关键词：X射线荧光光谱法； 不确定度； 评定

Key words：X-ray fluorescence spectrometry； uncertainty； evaluation

摘    要：对X射线荧光光谱法测定元素含量的不确定度的主要来源进行分析,对决定合成不确定度的大小的分量进行讨论,并以测定钒钛磁铁矿中的TFe含量为例说明整个评定过程。在X射线荧光光谱分析过程中,测定结果不确定度主要来自样品制备、仪器测量和数据处理过程;但是可以分别通过制备同一个样品的多个分析样片进行重复性测定、对同一个分析样片进行重复性测定和用标准样品的认定值与计算值之间的差异来估算。评定结果表明数据处理过程引入的不确定度最大,因此在建立分析方法时应该特别注意理论α系数的计算、校正模式的选择、基体校正、重叠谱线的干扰校正、计算回归等步骤。

Abstract: In this paper,the main sources of uncertainty in the X-ray fluorescence spectrometric determination of elements were analyzed,and the components which decide the value of combined uncertainty were discussed.The whole evaluation process was illustrated by determining the content of TFe in vanadium titano-magnetite.In the analytical process by X-ray fluorescence spectrometry,the uncertainty of determination results were mainly attributed to the sample preparation,the instrumental measurement and the data processing.However,it could be estimated by preparing several sample wafers with one sample for repeatability determination,the repeatability determination of one sample wafer,and comparing the difference between the certified value and calculated value of certified reference material.The evaluation results indicated that the uncertainty introduced in data processing was the largest.Therefore,the steps including the calculation of theoretical α coefficient,the selection of correction mode,the correction of matrix,the correction of spectral overlapping interference and the calculation of regression should be paid much attention in the establishment of analytical methods.