RP-HPLC-DAD DETERMINATION OF SIX TRITERPENES IN A HERBAL TONIC HOELEN

A reversed-phase high performance liquid chromatography-diode array detector method was newly developed and validated to simultaneously determine the content of six bioactive triterpenes, including 3-epi-dehydrotumulosic acid, dehydropachymic acid, dehydrotumulosic acid, pachymic acid, polyporenic acid C, and tumulosic acid, in the raw material of a herbal tonic Hoelen. The determination was performed on a Thermo ODS Hypersil column (150 mm x 4.6 mm, 5 mu m) kept at 35 degrees C during the elution. The mixture composed of acetonitrile and water containing 0.05% H3PO4 (v/v) was used as mobile phase under gradient elution, which was driven at a constant flow rate of 1.0 mL/min throughout the analysis. In addition, in order to monitor all the triterpenes in a single run, two wavelengths (210 nm for tumulosic acid and pachymic acid, 243 nm for the others) were selected. Last, the developed method was validated for linearity, range, limit of detection, precision, stability of sample solution, as well as accuracy and reproducibility. The established method could be used for routine analysis of the triterpenes in Hoelen and to assist in quality control of the tonic.