GC-MS测定食用油中DBP和DEHP含量的不确定度评定

Uncertainty Report on Determination of DBP and DEHP in Edible Oil by GC-MS Method

根据《食品安全国家标准食品中邻苯二甲酸酯的测定》(GB 5009.271-2016)第一法的规定,采用内标法的前处理方式、GC-MS进样,对食用油中DBP和DEHP的含量进行不确定度评定。该方法可改善由于实验过程中的样品损耗造成的回收率不稳定等问题,提高准确度和精密度。参照《测量不确定度评定与表示》(JJF 1059.1-2012),建立测量模型,对整个测量过程中不确定度的来源进行了分析。结果表明,制备空白添加标准曲线及标准曲线拟合过程引入的不确定度最大,其次是体积的量取、重复性和回收率,而样品称量引入的不确定度可忽略不计。

According to GB 5009.271-2016 method one, using internal standard method on pretreatment, the uncertainty on determination of DBP and DEHP in edible oil by GC-MS was evaluated. Using internal standard method could effectively improve the problem on the loss of sample during test and increase accuracy together with precision. According to JJF 1059.1-2012, establish a measurement model and analyze the sources of uncertainty. The results show that the uncertainty produced by blank adding standard curve together with standard curve fitting are the largest, followed with volume measurement, repeatability and recovery rate. The uncertainty produced by sample weighing is negligible.