不同东北黑木耳中硒含量测量的不确定度评估比较

The Uncertainty Evaluation and Comparison of the Determination of Selenium Content in Different Black Fungus

根据《化学分析中不确定度的评估指南》的要求和方法,对氢化物原子荧光光谱法测定不同东北黑木耳中硒含量的不确定度进行了评估与比较,建立了数学模型,分析了测定过程中产生不确定度来源,对产生不确定度较大的因素分析与探讨。结果表明硒含量较低的普通黑木耳测定过程中曲线拟合、方法的回收率及重复性是产生测定结果不确定度的主要因素,含量较高的富硒黑木耳方法的回收率是引起不确定度的最大因素,重复性、标准曲线配制及拟合曲线有一定不确定度贡献。该方法中试样制备产生的不确定度非常小,对测定结果影响不大,可以忽略不计。测定结果分别为:(0.105±0.01361)、(4.355±0.3674)mg/kg,(k=2)。

According to the requirement and method of Guidance on Evaluating the Uncertainty in Chemical Analysis,this article evaluated and compared the uncertainty of determination results of selenium content in different black fungus by hydride generation atomic fluorescence spectrometry,established mathematical models,analyzed Source of measurement uncertainty and discussed bigger factor of measurement.It resulted that the fitted curve,method recovery,repeatability were the major factor of uncertainty of ordinary black fungus.The method recovery was the paramount factor of uncertainty of Se-enriched black fungus.Repeatability,standard solution preparation and fitted curve made a portion of contribution to uncertainty.In this method,the sample preparation which made little contribution to uncertainty of measurement was ignored.The results of determination:(0.105±0.01361)mg/kg(k=2),(4.355±0.3674)mg/kg(k=2).