Determination of liquiritin, glycyrrhizin, hesperidin, cinnamic acid, cinnamaldehyde, honokiol and magnolol in traditional chinese medicinal preparation wuu-ji

A high-performance liquid chromatography method for the determination of liquiritin, glycyrrhizin, hesperidin, cinnamic acid, cinnamaldehyde honokiol and magnolol in a traditional Chinese medicinal preparation WuuJi-San, which contains Glycyrrhizae Radix, Citri Leiocarpae Exocarpium, Aurantii Fructus, Cinniamomi Ramulus and Magnoliae Cortex, was established. The samples were separated with a Cosmosil 5C18 -AR column by linear gradient elution using 0.03% phosphoric acid ( v/v ) - acetonitrile ( 0 min 95：5, 52 min 30：70 ) as the mobile phase at a flow-rate of 1.0 ml/min and the eluent was detected at 254nm. N-Propyl benzoate was used as the internal standard, seven regressive equations showing linear relationships between peak area ratios of each marker to n-propyl benzoate and concentrations were obtained. The recoveries of the titled markers were 84.77%, 87.07%, 79.81%, 72.71%, 72.72%, 77.15% and 73.74%, respectively. The coefficients of variation were less than 5% ( n=5 ). Very satisfactory and reproducible results were obtained within 52 min for simultaneous quantitation of seven markers. Different processes such as concentrating by reduced-pressure evaporation, freeze-drying and spray-drying were studied concerning their effects on marker contents. It showed minor effect on most markers except cinnamic acid and cionamaldehyde. Three commercial concentrated products of Wuu-Ji San were also analysed. The contents of marker substances in commercial preparations were quite different from those in standard decoction.