High-speed Liquid Chromatographic Analysis of Drugs. VII. Determination of Paeonol in Moutan Cortex

A rapid method for determining paeonol in Moutan Cortex ("Mudanpi"-root bark of Paeonia moutan) was established by high-speed liquid chromatography. Paeonol was separated in a 25 cm column of Zorbax CN, using a Shimadzu-Du Pont Model LC-2 liquid chromatograph, with 50% acetonitrile as the desorption solution. Separation was completed within 7 min. Paeonol in Moutan Cortex was extracted with methanol and the extract was injected directly into the column. Paeonol content was estimated from previously prepared calibration curves based on standard paeonol. At 275 nm, the precision of the determination was about ±1% and the detection limit was about 2 ng (S/N ratio, 3). It was concluded that this method is useful for the evaluation of Moutan Cortex.