原子荧光法测定富硒鸡蛋中硒的不确定度评定及探讨

Evaluation and discussion of uncertainty on selenium determination in selenium-rich eggs by atomic fluorescence spectrometry

摘要: 对原子荧光法测定富硒鸡蛋中硒含量的测量不确定度进行了评定。结合实验方法,建立数学模型,对数学模型中各个参数进行不确定度来源分析,并对不确定度评定过程中应注意的一些问题进行了初步探讨。结果表明由标准曲线所得的样品浓度和重复性实验是影响测量结果不确定度的主要因素,样品称量产生的不确定度非常小,对测量结果影响不大。该方法测定富硒鸡蛋中硒含量的扩展不确定度及最终结果表示为:(0.2705±0.0082)mg/kg(k=2)。

Abstract: The uncertainty for determination of selenium content in selenium-rich eggs by atomic fluorescence spectrometry was analyzed.A mathematical model in the process of measurement was established combining the test method.The uncertainty sources for each parameter in the model were analyzed.And that the problems in the process of evaluating uncertainty should be paid attention to was also discussed. Based on the analysis of uncertainty, the sample concentration from the standard curves and repeatability experiments were the major sources of uncertainty, while sample weighing revealed little effect on the final uncertainty. The expanded uncertainty of selenium in selenium-rich eggs was determined with this method, and the final result was expressed as: ( 0.2705 ± 0.0082) mg /kg (k = 2) .