离子色谱法测定白酒中氰化物含量的不确定度评定

Evaluation of Uncertainty in Determination of Cyanide Content in Baijiu by Ion Chromatography

依据《食品安全国家标准食品中氰化物的测定》(GB 5009.36—2023),采用离子色谱法测量白酒样品中氰化物含量,分析并计算各步骤引入的不确定度,并评估其扩展不确定度。结果表明,白酒样品中氰化物含量为0.201 mg·L^(-1),扩展不确定度为0.016 mg·L^(-1)(k=2)。测量不确定度主要由标准物质、中间液及系列标准工作液配制、样品前处理、标准曲线拟合、加标回收率及测量重复性5个方面引入,其中标准系列工作液配制过程引入的不确定度对总不确定度贡献最大。

According to GB 5009.36—2023,the content of cyanide in Baijiu samples was measured by ion chromatography,the uncertainty introduced in each step was analyzed and calculated,and its expanded uncertainty was evaluated.The results showed that the cyanide content in Baijiu samples was 0.201 mg·L~(-1),and the expanded uncertainty was 0.016 mg·L~(-1)(k=2).The measurement uncertainty is mainly introduced from five aspects:standard substance,intermediate liquid,and series standard working solution preparation,sample pre-treatment,standard curve fitting,spiking recovery rate,and measurement repeatability.Among them,the uncertainty introduced by the standard series working solution preparation process contributes the most to the total uncertainty.