原子吸收法测定牛乳中钙含量的不确定度

Uncertainty in determination of calcium content in milk by atomic absorption spectrometry

中文关键词:  钙含量  牛乳  原子吸收法  不确定度

英文关键词:calcium content  milk  atomic absorption method  uncertainty

中文摘要:

      目的 评定原子吸收法(atomic absorption spectrometry, AAS)测定牛乳中钙含量测量结果的不确定度。方法 从测量重复性、校准曲线等方面分析该方法的不确定度来源, 依据GB5009.92-2016《食品安全国家标准食品中钙的测定》建立数学模型, 根据JJF 1059.1-2012《测量不确定度的评定与表示》对测量结果的各不确定度来源进行分析和量化。分别计算各分量的不确定度, 最后计算检测结果的合成标准不确定度。 结果 当牛乳中钙含量为125 mg/100 g时, 其扩展不确定度为5 mg/100 g (k=2)。结论 不确定度主要来源于测量重复性、标准工作曲线、标准溶液配制3个方面, 本研究可为提高原子吸收法测定牛乳中钙含量的测量准确性提供参考。

英文摘要:

      Objective To evaluate the uncertainty of the results of determination of calcium content in milk by atomic absorption spectrometry (AAS). Methods The sources of uncertainty were analyzed from the aspects of measurement repeatability, calibration curve and so on. A mathematical model was established according to GB5009.92-2016 National food safety standard-Calcium determination in food. Sources of uncertainty for measurement results were analyzed and quantified by JJF 1059.1-2012 Evaluation and representation of measurement uncertainty. The uncertainty of each component was calculated separately, and finally the synthetic standard uncertainty of the detection result was calculated. Results When the calcium content in milk was 125 mg/100 g, the expanded uncertainty was 5 mg/100 g (k=2). Conclusion The uncertainty mainly comes from the measurement repeatability, standard working curve and standard solution preparation. This study can provide a reference for the improvement of the accuracy of the determination of calcium in milk by AAS.