石墨炉原子吸收光谱法测定干香菇中铅含量的不确定度评定

目的建立石墨炉原子吸收光谱法测定干香菇中铅含量的不确定度模型。方法按照CNAS-GL 006:2019 的评估方法, 建立结果不确定度评估数学模型, 量化不确定度分量, 计算扩展不确定度。结果经评定, 干香菇样品中铅的测定结果为0.64 mg/kg, 扩展不确定度为0.06 mg/kg (k=2)。结论影响铅测定不确定度的主要因素是试样溶液中铅的质量浓度的测定，且基本由标准曲线拟合引入。试样消化液定容体积和样品质量引入的不确定度较小，可忽略不计。

Uncertainty evaluation in determination of lead content in dried shiitake mushroom by graphite furnace atomic absorption spectrometry method

Objective To establish an uncertainty model for the determination of lead in dried mushrooms by graphite furnace atomic absorption spectrometry. Method According to the evaluation method of CNAS-GL 006:2018, a mathematical model for evaluating the uncertainty of results is established, the uncertainty components are quantified, and the expanded uncertainty is calculated. Result After evaluation, the determination result of lead in dried mushroom samples was 0.64 mg/kg, and the expanded uncertainty was 0.06 mg/kg (k=2). Conclusion The main factor affecting the uncertainty of lead determination is the determination of the mass concentration of lead in the sample solution, which is basically introduced by standard curve fitting. The uncertainty introduced by the constant volume of the sample digestion solution and the sample quality is small and can be ignored.