Simultaneous Determination of Four Flavonoids in Extract of Hawthorn Leaves by Microemulsion Liquid Chromatography / 分析化学

ABSTRACT

A novel system was developed for the rapid determination of vitexin, vitexin-2″-O-rhamnoside, rutin, and hyperoside in the extract of hawthorn(Crataegus pinnatifida Bge.) leaves with microemulsion liquid chromatography(MELC). The effect on the chromatography of varying the operating paramers was studied. The optimized MELC system with microemulsion was consisting of 1.0%(w/w) brij35-1.1%(w/w) n-butanol-0.1%(w/w) n-octanol-0.3%(v/v) triethylamine, the pH was adjusted to 2.5 with phosphoric acid. The type and concentration of surfactant, types of oil phase, the pH and triethylamine as the organic additive in microemulsion played an important role for separation of four flavonoids. MELC analysis was performed on a Venusil ASB C_(18) analytical column (150 mm× 4.6 mm, i.d., 5 μm). The flow rate was set at 0.8 mL/min and the eluent was detected at 340 nm for the four flavonoids. The calibration curves of the four flavonoids are linear(r>0.9995) over the concentration range of 0.95-140.0 mg/L. The mean recoveries are 98.6% to 101.6%. The results indicate that the optimized method was successfully applied to the analysis of four important flavonoids in the extract of hawthorn leaves.