Abstract: Two Pharmacologically active phenols (magnolol and honokiol) isolated from the Chinese herbal drug, Cortex Magnoliae Officinalis, were separated by capillary zone electrophoresis. After a series of optimization, baseline separation of magnolol and honokiol was obtained within 12 min by using the buffer system consisting of 0.03 mol·L^-1 borate and 0.01 mol·L^-1 phosphate, containing 20% methanol, at pH 10.80, and by DAD detection at 294 nm. With this simple and rapid method, the contents of two phenols in Cortex Magnoliae Officinalis were determined simultaneously by external standard method.

Key words: Cortex Magnoliae Officinalis, Magnolol, Honokiol, Quantitation, Cortex Magnoliae Officinalis, Magnolol, Honokiol, Quantitation, Capillary zone electrophoresis, Capillary zone electrophoresis