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

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

中文关键词:  石墨炉原子吸收光谱法  干香菇  铅含量  不确定度评定  标准曲线拟合

英文关键词:graphite furnace atomic absorption spectrometry  dried shiitake mushrooms  lead content  uncertainty evaluation  standard curve fitting

中文摘要:

      目的 评定石墨炉原子吸收光谱法测定干香菇中铅含量的不确定度。方法 按照CNAS-GL 006:2019《测量不确定度的要求的评估方法》, 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 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。

英文摘要:

      Objective To evaluate the uncertainty of determination of lead in dried shiitake mushroom by graphite furnace atomic absorption spectrometry. Methods According to CNAS-GL 006:2019 Evaluation method for requirements of measurement uncertainty, a mathematical model for result uncertainty evaluation was established, the components of uncertainty were quantified, and the expanded uncertainty was calculated. Results The assay result for lead in the dried shiitake mushroom sample was 0.64 mg/kg, with the expanded uncertainty of 0.06 mg/kg (k=2). Conclusion The main factor affecting the uncertainty of lead determination is the determination of lead mass concentration in sample solution, which is basically introduced by standard curve fitting. The uncertainties introduced by the constant volume of sample digest and sample quality are small and can be ignored.