高效液相色谱法测定能力验证样品(饮料)中咖啡因含量不确定度评定

Uncertainty evaluation for determination of caffeine in proficiency testing samples (beverages) by high performance liquid chromatography

中文关键词:  不确定度  咖啡因  能力验证  高效液相色谱法

英文关键词:uncertainty  caffeine  proficiency testing  high performance liquid chromatography

中文摘要:

      目的 对高效液相色谱法测定能力验证样品(饮料)中咖啡因含量的不确定度进行评定。方法 根据JJF1059.1-2012标准要求, 建立不确定度评估的数学模型, 通过对不确定度的各主要分量进行分析计算, 得出合成不确定度以及扩展不确定度, 最终进行测定结果的不确定度评定。结果 当能力验证样品中咖啡因的测定结果为156.9 mg/kg时, 在95%的置信区间下, 其扩展不确定度为5.8 mg/kg (k=2)。结论 采用高效液相色谱法测定饮料中咖啡因含量, 其不确定度的主要来源为标准溶液配制和标准曲线拟合, 该评估模型为检测饮料中咖啡因的不确定度评估提供了参考依据。

英文摘要:

      Objective To evaluate the uncertainty in the determination of caffeine in proficiency testing samples (beverages) by high performance liquid chromatography. Methods According to the JJF 1059.1-2012 standard requirement, the mathematical model of uncertainty evaluation was established after the sources of uncertainty were systematically analyzed. Through calculating the main components of uncertainty during analysis process, the combined and expanded uncertainties were obtained. Results When the content of caffeine in the proficiency testing sample was 156.9 mg/kg, the extended uncertainty was 5.8 mg/kg (k=2) under the 95% confidence interval. Conclusions The main sources of uncertainty are caused by the recovery for the preparation of standard solution and the establishment of standard curve with the least squares. It provides a reference for uncertainty evaluation of caffeine in beverages.