Determination of two flavonoids in Tongxian grapefruit leaves by HPLC-DAD

Objective: To develop a HPLC-DAD method to determine the content of naringin and rhoifolin in Tongxian grapefruit leaves.Methods: HPLC was performed on a Sepax Amethyst C18-H analytical column( 250 mm × 4.60 mm,5μm) with gradient elution using acetonitrile and 0.1% aqueous formic acid as the mobile phase at a flow rate of1.0m L/min. The detection wavelength was 283 nm for naringin,337 nm for rhoifolin. The column temperature was25℃ and the injection volume was 20μL. Results: The chromatographic peaks of naringin and rhoifolin could be separated well in the above cases.The linear ranges for the two flavonoids were 0.0653~0.6526 mg/m L and 0.0350~0.3505 mg/m L,respectively. The average recoveries were 98.68% and 98.47%,respectively.Conclusion: The established method could be used for the quality control of Tongxian grapefruit leaves.Harvest season and leaves age affect the content of two flavonoids significantly.