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目的:探讨石墨炉原子吸收分光光度法测定米面粉中镉含量不确定度的评定。方法:以参加国家食品安全风险评估中心食品安全风险监测质控考核——大米粉中镉含量定量分析为例,以CNAS-GL06《化学分析中不确定度的评估指南》(2006)为评定依据分析了整个检测过程所产生的不确定度。结果:给出采用石墨炉原子吸收分光光度法测定本次检测样品——大米粉中镉含量的扩展不确定度以及最终结果表示为:(161±26)μg/kg。结论:通过不确定度评定得出此次分析检测过程中不确定度的主要来源是样品制备过程、拟合的标准曲线计算产生的和仪器本身引入的不确定度,为今后采用石墨炉原子吸收分光光度法测定米面粉中镉含量的过程中有效地控制检测质量提供了可靠的理论依据。
Objective: To evaluate the uncertainty of the determination of cadmium in rice flour by graphite furnace atomic absorption spectrometry. Methods: To take part in the National Center for Food Safety Risk Assessment of food safety risk monitoring quality control - quantitative analysis of cadmium in rice flour as an example to CNAS-GL06 “Evaluation of Chemical Analysis of Uncertainty” (2006) as the basis for evaluation The uncertainty of the whole testing process is analyzed. Results: The extended uncertainty of the determination of cadmium in rice samples by graphite furnace atomic absorption spectrometry and the final result is (161 ± 26) μg / kg. Conclusion: The main sources of uncertainty in this analysis are the sample preparation process, the standard curve fitting calculation and the uncertainty introduced by the instrument itself. It is of great value for future application of graphite furnace atomic absorption Spectrophotometric determination of rice flour in the process of cadmium content in the effective control of test quality provides a reliable theoretical basis.