Abstract
The aim of the present work was to develop a multimethod for the analysis of five flavonoids in G.biloba leaves. The selected flavonoids were rutin, quercetin 3-D-galactoside, baicalin, isorhamnetin and rhamnetin. Leaf extraction was sonicated by using ethanol. The extract was passed through solid-phase extraction columns. Then, the extract was analyzed by high-performance liquid chromatography coupled in line with mass spectrometry. Calibration was carried out over the concentration range of 0.5 to 50 mg/L. The calibration data presented high correlation coefficients (>0.99). The limits of detection were 4.7, 5.3, 9.7, 6.9 and 12.9 µg/L for rutin, quercetin 3-D-galactoside, baicalin, isorhamnetin and rhamnetin, respectively. Mean recoveries ranged from 66% to 72% for the HPLC–MS analysis. Reproducibility was estimated by the relative standard deviation (RSD) which ranged between 2.21 and 3.93%. Five flavonoids were found to be present in G.biloba leaves. The developed method was readily applied to quantify the flavonoids in some commercially available G.biloba leaves.
