Abstract: Aim An HPLC-UV method for the analysis of Traditional Chinese Medicine (TCM) preparation, Sijunzi decoction, has been developed. Four flavonoid marker compounds, liquiritigenin, liquiritin, isoliquiritigenin, and isoliquiritin, from Radix Glycyrrhizae were quantitatively analyzed in this preparation. Methods The separation was performed on a reversed-phase C18 column by using a gradient elution with mobile phase of (A) water-formic acid (100∶0.04, V/V) (pH 3) and (B) acetonitrile. The mobile phase gradient was set from 0-5 min at 10% of B and 45 min to 90% of B. The assay was carried out at a flow rate of 0.2 mL·min^-1 at room temperature with the UV detection wavelengths at 280 nm and 368 nm. Results The extract (25 mg·mL^-1) of Sijunzi decoction contains 1.47 μg·mL^-1 liquiritigenin, 16.40 μg·mL^-1 liquiritin, 0.66 μg·mL^-1 isoliquiritigenin, and 2.12 μg·mL^-1 isoliquiritin. The recoveries for the sample preparation of the markers were 102.2%, 97.7%, 100.3%, and 99.9%, respectively. Conclusion The method is simple and accurate. This study reports a routine quantitative method for the analysis of multiple components in Sijunzi decoction by HPLC.

Key words: traditional Chinese medicine, traditional Chinese medicine, Sijunzi decoction, HPLC, Sijunzi decoction, HPLC