自动电位滴定法测定白酒中酸酯总量的不确定度评定

Evaluation of Uncertainty in the Measurement of Total Acid and Ester in Baijiu by Automatic Potentiometric Titration

依据《测量不确定度评定和表示》(JJF 10591.1-2012)和《白酒分析方法》(GB/T 10345-2022),采用自动电位滴定法测定白酒中的酸酯总量,并建立数学模型对白酒测定过程中引入的不确定度进行分析和评定。结果表明,白酒中的酸酯总量为(55.7±0.6)mmol·L^(-1)(k=2);总酸、总酯分别消耗标准滴定溶液的体积所引入的不确定度分量贡献最大,酒样重复性测定和标准滴定溶液浓度所引入的不确定度分量贡献次之,而引入不确定度分量贡献最小的是酒样移取体积。

According to JJF 10591.1-2012 and GB/T 10345-2022,the total amount of acid and ester in Baijiu was determined by automatic potentiometric titration,and the uncertainty introduced in the determination of Baijiu was analyzed and evaluated by establishing a mathematical model.The results showed that the total amount of acid and ester in Baijiu was(55.7±0.6)mmol·L^(-1)(k=2).The uncertainty component of total acid and total ester consumed by the volume of standard titration solution contributed the most.The uncertainty components introduced by the repeatability measurement of Baijiu samples and the concentration of standard titration solutions were secondary.The smallest contribution of introducing uncertainty components was the removal volume of Baijiu sample.