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.