分光光度法测定保健食品中总皂甙的不确定度评定

Uncertainty Evaluation of Total Ginsenosides Measurement in Health Foods by Spectrophotometry

目的评定分光光度法测定保健食品中总皂甙含量的测量不确定度。方法根据测定过程建立数学模型,分析引起测量结果的不确定度来源,并计算各分量引入的不确定度、合成标准不确定度及扩展不确定度。结果当P=95%时,该方法测量保健食品中总皂甙引入的扩展不确定度为±13.2%。结论该方法在测定保健食品总皂甙不确定度的主要来源为μ(x)和μ(Rec),在测定样品时应对方法测试体系的重复性加以控制。

Objective To evaluate the measurement uncertainty for total ginsenosides in health foods by spectrophotometry.Methods The mathematical model was established based on the measuring process.The uncertainty sources which the measurement results caused were analyzed.Combined standard uncertainty and expanded uncertainty were calculated.Results Expanded uncertainty of total ginsenosides in health foods by spectrophotometry was±13.2% at 95% confidence level.Conclusion The main uncertainty sources of methods are repeated measurement and extraction efficiency in sample preparation process,so the repeatability of methods in test system should be controlled in sample determining process.