酱香型白酒酒醅中乙醇测定方法的不确定度评定

Evaluation of Uncertainty in the Determination of Ethanol in Jiangxiang Baijiu Fermented Grains

为保证实验室顶空气相色谱法测定酱香型白酒酒醅中乙醇含量方法的有效性,根据JJF 1059.1—2012《测量不确定度评定与表示》评定了乙醇测量的不确定度。通过分析测量过程中引入的各项不确定度分量,计算得到测量结果的合成标准不确定度和扩展不确定度。结果表明当酱香型白酒酒醅中乙醇含量为24.81 g/kg时,扩展不确定度为1.24 g/kg,包含因子k=2。该方法不确定度的主要来源为标准溶液配制、测量重复性和标准曲线拟合。

In order to ensure the validity of the determination of ethanol content in Jiangxiang Baijiu fermented grains by headspace gas chromatography,the uncertainty of the ethanol determination process was evaluated according to the national standard JJF 1059.1-2012.By analyzing the uncertainty components introduced in the determination process,the combined standard uncertainty and the expanded uncertainty of the determination results were calculated.The results showed that when the ethanol content in the fermented grains was 24.81 g/kg,the expanded uncertainty was 1.24 g/kg,and the coverage factor k was 2.The main sources of the uncertainty in this method were standard solution preparation,measurement repeatability,and standard curve fitting.