Simultaneous determination of liquiritin, nodakenin and glycyrrhizinin Guibi-tang, a traditional herbal prescription by HPLC-PDA

A simple, convenient, rapid and accurate high-performance liquid chromatographic (hplc) method was established for the simultaneous determination about three ingredients of a traditional herbal prescription, guibi-tang (gbt): liquiritin (1), nodakenin (2) and glycyrrhizin (3). chromatographic analysis on the three components was separated within 35 min on a gemini c18 column and maintained at 40°c. the mobile phase consisted of water with 1.0% (v/v) acetic acid (solvent a) and acetonitrile with 1.0% (v/v) acetic acid (solvent b) in gradient mode at a flow-rate of 1.0 ml/min. chromatograms were acquired at 254, 280 and 330 nm in a photodiode array (pda) detector. the calibration curves showed excellent linearity (r2=1.0000). the average recovery of three compounds was ≥93.5%, with a relative standard deviation (rsd) of ≤2.0%. the intra-day and inter-day precision (rsd) of the three components were 0.04%-3.04% and 0.11%–2.48%, respectively. the contents of compounds 1–3 in gbt were 1.09-1.10, 2.35-2.37 and 0.81-0.82 mg/g, respectively.