Abstract: A method for the determination of p-coumaric acid in Hedyotis diffusa Willd. from different sources by reversed-phase high performance liquid chromatography (RP-HPLC) has been developed. p-Coumaric acid was successfully separated on a DiamonsilTM ODS column (4.6 mm i.d.×250 mm, 5 μm) at ambient temperature, using a mixture of CH3CN-20 mmol/L NH4Ac (pH 4.0) (15∶85, v/v) as mobile phase and detection at 308 nm. The flow rate was 1.0 mL/min. There was good linear relationship (r=0.9996) between the mass concentration and the peak area of p-coumaric acid in the range of 4.04-202 mg/L. The recoveries were found to be in the range of 97.4%-102.2%. The results of the experiments have demonstrated that the established method is rapid and simple with good accuracy and reproducibility. The method is suitable for use in quality control of Hedyotis diffusa Willd. from different sources.

Key words: Chinese medical material , Hedyotis diffusa Willd., p-coumaric acid, reversed-phase high performance liquid chromatography