Objective: To establish a dual-wavelength high performance liquid chromatography method for uncertainty analysis of chlorogenic acid

forsythin and aicalin in Shuanghuanglian Oral Liquid. Method: According to the technical requirements of JJF 1059—1999(Evaluation and expression of uncertainty in measurement)

each active component of uncertainty was calculated the variable parameters among the procedures.The combined uncertainty and extended uncertainty and reported uncertainty were finally obtained by synthesized the uncertainties of various component variables. Result: Uncertainty evaluation for chlorogenic acid was ±2.23%

forsythin was ±9.18% and aicalin ±0.84%. Conclusion: The uncertainty of the reference standard quality was the main source of three components measurement uncertainty in Shuanghuanglian Oral Liquid.