高效液相色谱法测定油脂中苯并[a]芘含量的不确定度评定

Evaluation of Uncertainty in Determination of Benzo[a]Pyrene in Oil by High Performance Liquid Chromatography

本文建立了高效液相色谱法测定油脂中苯并[a]芘含量不确定度的评定方法。按照国家标准GB 5009.27-2016进行检测,通过分析整个实验过程不确定度因素,包括样品的称量、样品定容体积、标准溶液及配制、标准曲线的拟合以及重复性测试过程带来的随机效应,建立了油脂中苯并[a]芘含量不确定度的数学模型,并且进行了量化。实验结果表明:取置信区间95%,压榨菜籽油中苯并[a]芘含量可表示(15.2±0.68)μg/kg(k=2)。整个检测过程中,标准溶液及配制引入的不确定度为主要不确定度来源,其相对标准不确定度为1.74%,占比约45.1%,其次为随机效应引入的不确定度,占比约31.8%,其它因素占比约23.1%。因此,为了提高检测结果的准确性。实际检测过程中应该严格按照国家标准操作、选用高纯度的标准品和高级别的器具、规范标准溶液及配制过程、定期维护核查检测设备等。

This experiment established an evaluation method for the uncertainty in the determination of benzo[a]pyrene in oils using high-performance liquid chromatography.According to GB 5009.27-2016,a measurement model of the uncertainty was established to analyze and quantified the factors in total experimental process,including sample weighing,volume of sample solution,standard solution and preparation,fitting of standard curve,and random effects caused by the repeatability testing process.The experimental results showed that with a confidence interval of 95%,the content of benzo[a]pyrene in pure rapeseed oil could be expressed as(15.2±0.68)μg/kg(k=2).In the experimental process,the main source of uncertainty was the standard solution and preparation,with a relative standard uncertainty of 1.74%,accounting for approximately 45.1%,followed by the uncertainty introduced by random effects,accounting for approximately 31.8%,and others accounting for approximately 23.1%.Therefore,in order to improve the accuracy of testing results,national standards should be strictly followed,high-purity standards and high-level instruments should be selected,standard solution and preparation process should be standardized,and equipment should be regularly maintained and verified in the actual detection process.