Objective To evaluate the uncertainty of determination of caffeine in total brass using phellinus linteus spectrophotometer. Methods According to JJF1059.1-2012 evaluation and Expression of Uncertainty in Measurement, a mathematical model was established to determine the uncertainty of total brass in phellinus linteus spectrophotometer. The sources of uncertainty which may be introduced into the measurement process were analyzed and calculated, and then the relative uncertainty and extended uncertainty were synthesized. Results The standard curve was a major source of uncertainty, curve fitting account for the largest proportion. Conclusion In the determination process of total flavonoids, care should be taken to select a good linear standard curve.
标题：分光光度法测定桑黄中总黄酮的不确定度评定
英文标题：Evaluation of uncertainty in determination of total flavone in Phellinus spp. by spectrophotometer
