柴油中脂肪酸甲酯检测方法的变化及不确定度评定

Change of FAME Detection Method in Diesel Oil and Evaluation of Uncertainty

针对GB/T 23801-2021中脂肪酸甲酯(FAME)检测方法的变化进行了比较,并对新方法的检测能力和准确性进行了研究。通过对方法的检出限和定量限进行测定,得出方法的检出限和定量限分别为0.003 6,0.012 0 g/L,表明该法能够准确灵敏地检测柴油中FAME含量。对不确定度的来源进行了全面分析,对每一种不确定度分量和合成不确定度进行了评定,得出方法合成相对不确定度为0.052 1,当k=2(置信概率为95%)时,扩展不确定度为0.276 g/L,测定结果为(2.649±0.276)g/L。标准曲线拟合和标准溶液配制为不确定度产生的主要因素。

The changes of fatty acid methyl ester(FAME)detection methods in GB/T 23801-2021 were compared,and the detection ability and accuracy of the new method were studied.By measuring the detection limit and quantification limit of the method,it was found that the detection limit and quantification limit of the method were 0.0036 g/L and 0.0120 g/L,respectively,indicating that the method can accurately and sensitively detect the FAME content in diesel.A comprehensive analysis was conducted on the sources of uncertainty,and various uncertainty components and combined uncertainties were evaluated.The combined relative uncertainty of the method was 0.0521.When k=2(confidence probability of 95%),the expanded uncertainty was 0.276 g/L,and the measurement result was(2.649±0.276)g/L.The fitting of standard curves and the preparation of standard solutions are the main factors causing uncertainty.