Study on determination of pentacyclic triterpenoids in Chaenomeles by HPLC-ELSD.

A new direct high-performance liquid chromatography analytical method using evaporative light scattering detection (ELSD) for the simultaneous determination of the major pentacyclic triterpenoids in Chaenomeles (Chinese medicinal herb) has been developed. The simultaneous separation of the seven pentacyclic triterpenoids was achieved on a Zorbax Stable Bound (4.6 mm x 100 mm i.d., 1.8 microm) C(18) column by gradient elution with acetonitrile-water as the mobile phase and detected with ELSD. This method provides good reproducibility and sensitivity for the quantification of seven major pentacyclic triterpenoids, namely erythodiol, betulin, acetyl ursolic acid, ursolic acid, oleanolic acid, betulinic acid, and pomolic acid, respectively. The relative standard deviation (RSD) of overall intra-day variations was less than 2.2%, and the RSD of inter-day variations was less than 2.8%. The standard recoveries (three different concentrations of markers: 0.1, 0.5, and 2.0 mg) ranged from 96-104%. The results demonstrate that this method is simple, sensitive, selective, and suitable for the quality control of this commonly used Chinese medicinal herb.