Simultaneous analysis of glycyrrhizin, paeoniflorin, quercetin, ferulic acid, liquiritin, formononetin, benzoic acid and isoliquiritigenin in the Chinese proprietary medicine Xiao Yao Wan by HPLC

A high performance liquid chromatography coupled with photodiode-array detection method was developed for simultaneous determination of glycyrrhizin, paeoniflorin, benzoic acid, quercetin, ferulic acid, formononetin, liquiritin and isoliquiritigenin in the Chinese proprietary medicine “Xiao Yao Wan” (XYW). The analysis was performed by reverse phase gradient elution, using an aqueous mobile phase (containing 0.1% phosphoric acid) modified by acetonitrile and detection made simultaneously at four wavelengths. The method was validated for accuracy, precision and limits of detection and quantification. Ten batches of XYW obtained from different pharmaceutical companies were analyzed and found to contain different amounts of the eight bioactive markers. This method could be used for quality assessment of this herbal medicine.