DETERMINATION OF FLAVONES IN LOPHATHERUM GRACILE BY LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRY

Lophatherum gracile Brongn. (L. gracile) has been used for food and medicine in China for thousands of years. Flavonoids are one of the main bioactive components of this herb. A reliable method was established using liquid chromatography with tandem mass spectrometry to determine the concentrations of seven flavonoids. The separation was performed using a C18 column at 40°C and the mobile phase was a mixture of methanol and 0.3% formic acid (v/v) in water in gradient elution mode at a flow rate of 1 mL/min. Quantification was performed through tandem mass spectrometry with negative electrospray ionization and multiple reaction monitoring at m/z [M-H]−. The method was validated using calibration curves, limits of detection and quantification, precision, repeatability, stability, and accuracy. Seven compounds in eleven samples were determined, and there were significant differences in the concentrations of isoorientin, swertiajaponin, afzelin, luteolin-7-O-β-D-glucoside, vitexin, isovitexin, and swertisin. ...