高效液相色谱法测定乳粉中叶黄素含量不确定度评定

目的评定高效液相色谱法测定乳粉中叶黄素的测量结果的不确定度。方法根据GB5009.248—2016《食品安全国家标准食品中叶黄素的测定》中的方法检测乳粉中的叶黄素,分析与量化高效液相色谱法测定乳粉中叶黄素的实验过程,对标准溶液,样品前处理,标准曲线拟合,仪器重复进样等方面进行不确定度分析,建立数学模型,最终合成乳粉中叶黄素含量的不确定度。结果在95%的置信区间下,乳粉中叶黄素含量的测定结果的扩展不确定度为26μg/100g,乳粉中叶黄素含量测定结果为(194±26)μg/100g,k=2。结论在叶黄素含量测定过程中,最小二乘法拟合标准曲线产生的不确定度在该法中影响最大,即标准溶液曲线所涉及到的浓度值是影响测量不确定度的主要因素。

Evaluation of the measurement uncertainty in determination of lutein content in milk power by high performance liquid chromatography

Objective To evaluate the uncertainty of determination of lutein in milk powder by high performance liquid chromatography. Methods According to GB 5009.248—2016 National food safety standard Determination of lutein in foods, the lutein in milk powder was detected, the experimental process for the determination of lutein in milk powder by high performance liquid chromatography was analyzed and quantized. The uncertainty analysis of standard solution, sample pretreatment, standard curve fitting, instrument repeated injection and other aspects was carried out to establish mathematical model, and finally the uncertainty of lutein content in synthetic milk powder was synthesized. Results Under the 95% confidence interval, the extended uncertainty of the determination of lutein content in milk powder was 26 μg/100 g, and the determination result of lutein content in milk powder was(194±26) μg/100 g, k= 2. Conclusion In the process of lutein content determination, the uncertainty generated by the least-square method fitting the standard curve has the greatest influence in this method, the concentration value involved in the standard solution curve is the main factor affecting the measurement uncertainty.