压力罐消解-原子吸收光谱法测定花生中镉含量不确定度评定

Evaluation of uncertainty in determination of cadmium in peanut by pressure tank digestion-atomic absorption spectrometry

对压力罐消解-原子吸收光谱法测定花生中镉含量不确定度进行评定。依据JJF 1135-2005《化学分析测量不确定度评定》及JJF 1059.1-2012《测量不确定度评定与表示》中不确定度评定的基本程序,建立数学模型,分析压力罐消解-原子吸收光谱法测定花生中镉含量过程中引入的各测量不确定度分量,计算得到测量结果的合成标准不确定度和扩展不确定度。评定结果表明:拟合标准工作曲线所产生的不确定度对结果的影响最大,其次是镉标准溶液的配制和测量重复性引起的不确定度,试样称量的不确定度对结果的影响最小。评定结果可以对分析检测结果的准确程度和方法的可靠性研究提供参考。

The uncertainty of determination of cadmium in peanut by pressure tank digestion-atomic absorption spectrometry was evaluated. According to JJF 1135-2005《Chemical Analysis Measurement Uncertainty Evaluation》 and JJF 1059.1-2012《Measurement Uncertainty Evaluation and Representation》,the basic procedure of uncertainty evaluation, a mathematical model was established. The measurement uncertainty components introduced in the process of measuring cadmium content in peanuts by pressure tank digestion -atomic absorption spectrometry were analyzed, and the synthetic standard uncertainty and extended uncertainty of the measurement results were calculated. The evaluation results showed that the uncertainty caused by fitting the standard working curve has the greatest impact on the results, followed by the uncertainty caused by the preparation and measurement repeatability of the cadmium standard solution, and the influence of the uncertainty of the sample weighing on the results was the smallest. The evaluation results can provide reference for the accuracy of the analytic results and the reliability of the method.