微波消解-石墨炉原子吸收光谱法测定刺梨中镉的不确定度评定

Uncertainty Evaluation of Determination of Cadmium in Rosa Roxbunghii by Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry

根据GB 5009.15-2014《食品安全国家标准食品中镉的测定》和JJF 1059.1-2012《测量不确定度评定与表示》中的有关规定,建立了微波消解-石墨炉原子吸收光谱法测定刺梨中镉元素含量的不确定度数学模型,分析不确定度来源及其量化各因素不确定度并进行合成。结果表明,样品上机测定过程引入的不确定度贡献最大,贡献率为84.1%;其次为标准溶液配制,贡献率为13.4%。当刺梨中镉元素含量为0.0138mg/kg,其扩展不确定为0.0014mg/kg(P=95%,k=2)。

According to the relevant regulations in GB 5009.15-2014“Determination of Cadmium in Foods”and JJF 1059.1-2012“Measurement and Expression of Measurement Uncertainty”,microwave digestion-graphite furnace atomic absorption spectrometry was used to determine thorn a mathematical model for the uncertainty of cadmium content in pears,analyzing the sources of uncertainty and quantifying the uncertainty of each factor and synthesizing them.The results showed that the uncertainty of the introduction of the sample on the sample was the largest,with a contribution rate of 84.1%;followed by the standard solution,with a contribution rate of 13.4%.When the content of cadmium in thorn pear is 0.0138mg/kg,the expansion is not determined to be 0.0014 mg/kg(P=95%,k=2).