Determination of Total Flavonoids in Leaves of Glycyrrhiza glabra L. by Spectrophotometry

Four coloration methods were applied for the determination of total flavonoids in leaves of Glycyrrhiza glabra L.from Xinjiang.Two absorption wavelengths were selected in terms of wavelength scanning of 80% ethanol extract from the leaves and standard controls including rutin,quercetin and liquiritin.Standard curves for three standard controls by four coloration methods were established.The accuracy,stability,repeatability and recovery rates of four coloration methods were also determined.The content of total flavonoids were determined using AlCl3-CH4O coloration at 314 nm and quercetin as the control.The RSD for accuracy,stability,repeatability and recovery rate were 0.92%,0.87%,2.15% and(105.02 ± 1.11)%,respectively.