高效液相色谱法测定保健品益生菌粉中三氯蔗糖的不确定度评估

目的 按照食品安全国家标准GB 22255-2014规定的高效液相色谱法对保健品益生菌粉中三氯蔗糖含量进行测定。根据CNAS-GL006：2019要求以及JJF1059.1-2012对测定过程中影响检验结果的各个分量进行评估。方法 通过对测量重复性、标准品溶液配制、样品溶液的配制、高效液相色谱仪以及标准曲线拟合测量偏差这5个方面引入的不确定度进行分析,并确定各个不确定度分量,得到扩展不确定度。结果 经测定,保健品益生菌粉中三氯蔗糖含量为(0.78±0.046)g/kg,P=95%,(k=2)结论 高效液相色谱法因素对测量不确定度影响显著,由检验方法重复测量和标准品溶液配制体现。

Uncertainty evaluation for the determination of sucralose in probiotic powder of health food by high performance liquid chromatography

Objective To evaluate the uncertainty for determination of sucralose in probiotic power of health food by high performance liquid chromatography (HPLC). Methods According to CNAS-GL 006:2019 Guidance on evaluating the uncertainty in chemical analysis and JJF 1059.1-2012 Evaluation and expression of measurement uncertainty, the sucralose in probiotic power of health food was measured by HPLC, and the mathematical model of uncertainty was established. The uncertainty was analyzed from 5 aspects, including the repeatability of determination, the preparation of standard solution, the preparation of sample solution, high performance liquid chromatography and the measurement deviation of standard curve fitting. The extended uncertainty was obtained by determining each uncertainty component. Results The confidence interval was 95%, and the content of sucralose in probiotic power was (0.78±0.0384) g/kg, (k=2). Conclusion The influence of the factors of high performance liquid chromatography on the measurement uncertainty is obvious, which is reflected by repeated measurement of test method and preparation of standard-solution.