黄酒中尿素含量测定方法的不确定度分析

Uncertainty Analysis of Determination for Urea Content in Yellow Rice Wine

基于柱前衍生高效液相色谱荧光检测器(HPLC-FLD)测定黄酒中尿素含量的检测方法,以及国家计量技术规范JJF 1059.1-2012《测量不确定度评定与表示》,以检测原理为基础建立数学模型,分析高效液相色谱法测定黄酒中尿素含量过程中引入的各项不确定度,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,优化条件的高效液相色谱法线性良好(R2>0.999),回收率高(平均回收率>92%),尿素检出限为0.024mg/L,定量限为0.086 mg/L,可作为质监部门与企业检测黄酒中尿素含量的参考方法。该检测方法不确定度主要来源于尿素标准溶液衍生,其次为尿素标准溶液配制及测量重复性所引入的不确定度。黄酒中尿素含量表示为(C±U)mg/L,k=2。

A determination method of urea content in yellow rice wine by using high performance liquid chromatography with fluorescence detection（HPLC-FLD） has been developed. According to JJF 1059-2012 Evaluation and Expression of Uncertainty in Measurement, the mathematical model was established based on the given testing principle, and the components of uncertainty in the measuring process of determining urea in yellow rice wine using HPLC-FLD method were studied and analyzed, and then the combined uncertainty and the expanded uncertainty were calculated. The results showed that the optimization of high performance liquid chromatography with good linearity（R2 0.999）, recovery rate was high（92%）, urea detection limit was 0.024 mg/L, quantitative limit was 0.086 mg/L, and it could be used as the basic method of the urea content in quality supervision departments and enterprises in the detection of rice wine. The major factors of uncertainty in measurement of this method are derived of urea standard solution, and the minor ones were the preparation of urea standard solution and the repeatability of measurement. Urea content in yellow wine could be expressed as X =（C ± U） mg/L, k = 2.