高效液相色谱法测定果汁饮料中山梨酸含量的不确定度评定

目的 评定高效液相色谱法(high performance liquid chromatography, HPLC)测定果汁饮料中山梨酸的不确定度。方法 采用HPLC法测定果汁饮料中山梨酸, 确认不确定度的来源和大小, 合成不确定度, 计算扩展不确定度。结果 果汁饮料中山梨酸的含量为94.90 mg/kg, 扩展不确定度为5.86 mg/kg(P=95%, k=2)。结论 标准物质与标准曲线拟合对不确定度的影响较大, 样品制备(称量、溶液定容)、回收率、样品测量(仪器测定、测量重复性)和峰面积对不确定度的影响较小。

Uncertainty evaluation of the determination of sorbic acid in juice by high performance liquid chromatography

Objective To evaluate the uncertainty of the determination of sorbic acid in juice by high performance liquid chromatography (HPLC). Methods The sorbic acid in juice was determined by HPLC, the source and value of uncertainty were confirmed, and the synthetic uncertainty and the extended uncertainty were calculated. Results The content of sorbic acid in juice was 94.9 mg/kg, and the expansion of uncertainty was 5.86 mg/kg (P=95%, k=2). Conclusion The standard substance and the standard curve fitting have a great influence on the uncertainty. The sample preparation (weighing, constant volume), recovery rate, measurement (instrument, repeatability) and peak area have a little effect on the uncertainty.