液相色谱法测定保健食品中番茄红素的不确定度评定

目的评定高效液相色谱法(high performance liquid chromatography,HPLC)测定保健食品中番茄红素含量的不确定度。方法依据《测量不确定度评定与表示》(JJF1059.1-012),分析番茄红素含量测定过程中的不确定度来源,通过建立数学模型量化不确定度分量,计算合成不确定度及扩展不确定度。结果本研究测得的保健食品中番茄红素的含量为(51.3±6.8)g/kg,扩展不确定度为6.8 g/kg(k=2)。测定过程的不确定度来源主要有样品称量、标准溶液的配制及标准曲线拟合、样品前处理、样品重复性测定及仪器本身带来的不确定度。结论 HPLC法测定番茄红素的不确定度主要来源于标准溶液的校正,其次为样品前处理引入的不确定度,其他因素的影响相对较小。

Uncertainty evaluation of the determination of lycopene in health food by high performance liquid chromatography

Objective To evaluate the uncertainty of determination of lycopene in health foods by high performance liquid chromatography (HPLC). Methods According to the JJF1059.12-012 Chinese regulation on the valuation and expression of uncertainty in measurement, the sources of uncertainty in determination of lycopene were analyzed. Furthermore, the combined uncertainties and expanded uncertainties were calculated based on the established mathematic models. Results The content of lycopene in health foods in this study was (51.3±6.8) g/kg and the accompanying expanded uncertainty was 6.8 g/kg (k=2). And the main sources of uncertainty in the determination were as follows: sample weighing, preparation of standard solution and the standard curve fitting, sample pretreatment, repeatability of sample and instrument itself. Conclusion The calibration of standard solution contributes predominantly to the uncertainty of lycopene determination by HPLC, followed by the sample pretreatment and the influence of other factors are relatively small.