电感耦合等离子体发射光谱法测定奶粉中微量元素含量的不确定度评定

Uncertainty evaluation of determination of trace elements in milk powder by inductively coupled plasma atomic emission spectrometry

中文关键词:  电感耦合等离子体发射光谱法  微量元素  不确定度

英文关键词:inductively coupled plasma emission spectrometry  trace elements  uncertainty

中文摘要:

      目的 评定电感耦合等离子体发射光谱法测定奶粉中微量元素含量的不确定度。方法 对电感耦合等离子体发射光谱法测定奶粉中锌、铁、锰、铜、钙、镁、钠、钾8种微量元素的整个实验过程可能引入的各种不确定度来源进行分析, 建立不确定度数学模型, 计算各不确定度分量及扩展不确定度。结果 在置信区间为95%的范围内, 奶粉中钙、镁、钠、钾、锌、铁、锰、铜的扩展不确定度分别为0.07330、0.1136、0.07380、0.07340、0.05598、0.05272、0.08542、0.05190。结论 标准溶液配制带来的不确定度对钙、钠、钾、锌、铁、铜元素的贡献率最大, 由标准曲线拟合带来的不确定度对镁元素的贡献率最大, 测量结果重复性带来的不确定度对锰的贡献率最大。

英文摘要:

      Objective To evaluate the uncertainty of determination of trace elements in milk powder by inductively coupled plasma emission spectrometry. Methods The various sources of uncertainty that may be introduced in the entire experimental process of determining the eight trace elements of zinc, iron, manganese, copper, calcium, magnesium, sodium, and potassium in milk powder by inductively coupled plasma emission spectrometry were analyzed. The mathematical model of uncertainty was established, and the uncertainty components and extended uncertainty were calculated. Results Within the confidence interval of 95%, the extended uncertainties of calcium, magnesium, sodium, potassium, zinc, iron, manganese and copper in milk powder were 0.07330, 0.1136, 0.07380, 0.07340, 0.05598, 0.05272, 0.08542 and 0.05190, respectively. Conclusion The uncertainty brought by the preparation of the standard solution has the largest contribution rate to calcium, sodium, potassium, zinc, iron, and copper. The uncertainty brought by the standard curve fitting has the largest contribution rate to the magnesium element. The uncertainty caused by repeatability of measurement results contributed the most to manganese.