气相色谱内标法测定白酒中乙酸乙酯含量的不确定度评定

Evaluation of Uncertainty in the Determination of Ethyl Acetate in Baijiu by Internal Standard Gas Chromatography

采用气相色谱内标法测定白酒中乙酸乙酯含量,通过考察测定过程中的影响因素,分析不确定度来源,评定各个不确定度分量。结果表明,标准溶液配制、样液移取定容体积及标准曲线拟合引入的不确定度对合成测量不确定度的贡献较大。当清香型白酒中乙酸乙酯含量为0.89 g·L^(-1)时,扩展不确定度为0.05 g·L^(-1)(k=2)。

The internal standard method of gas chromatography was used to determine the content of ethyl acetate in Baijiu.Through investigating the influencing factors in the determination process,the source of uncertainty was analyzed,and each uncertainty component was evaluated.The results showed that the uncertainty introduced by standard solution preparation,constant volume of sample solution transfer and standard curve fitting contributed greatly to the uncertainty of synthetic measurement.When the content of ethyl acetate in light flavor Baijiu is0.89 g·L~(-1),the expanded uncertainty is 0.05 g·L~(-1)(k=2).