微波消解-原子荧光法测定大米粉中总砷含量的不确定度评定

Uncertainty evaluation for the determination of total arsenic in rice by atomic fluorescence spectrometry with microwave digestion

中文关键词:  微波消解  原子荧光法  砷  不确定度

英文关键词:microwave digestion  atomic fluorescence method  arsenic  uncertainty

中文摘要:

      目的 评定微波消解-原子荧光法测定大米粉中总砷含量的不确定度。方法 依据JJF 1059.1-2012《测量不确定度评定与表示》及CNAS-GL 006-2019《化学分析中不确定度的评估指南》, 采用微波消解-原子荧光法测定大米粉质控样品中总砷含量, 建立数学模型, 并对整个分析过程中产生的不确定度分量进行评定。结果 当大米粉质控样品中砷测定结果为0.156 mg/kg时, 其扩展不确定度为0.0067 mg/kg(k=2)。结论 量化后测定过程中各影响因素所产生的不确定度表明实验过程的不确定度主要来源于标准曲线拟合, 其次是加标回收率及测量重复性。

英文摘要:

      Objective To evaluate the uncertainty of determination of total arsenic content in rice flour by microwave digestion-atomic fluorescence spectrometry. Methods According to JJF 1059.1-2012 Measurement uncertainty evaluation and expression and CNAS-GL 006-2019 Evaluation guide for uncertainty in chemical analysis, the content of total arsenic in rice flour quality control samples was determined by microwave digestion-atomic fluorescence spectrometry, a mathematical model was established, and the uncertainty components generated in the whole analysis process were evaluated. Results When the arsenic determination result of the quality control samples of rice flour was 0.156 mg/kg, the expansion uncertainty was 0.0067 mg/kg, k=2. Conclusion The uncertainty caused by the influencing factors in the measurement process after quantification indicates that the uncertainty of the experimental process mainly comes from the standard curve fitting, followed by the spiked recovery rate and measurement repeatability.