Abstract
A simple, accurate, sensitive and reproducible spectrofluorimetric method has been developed for the analysis of quercetin in lotus (Nelumbo nucifera) leaves extract and glycyrrhizin in liquorice (Glycyrrhiza glabra) root extract. Quercetin and glycyrrhizin show strong fluorescence in methanol having excitation wavelength at 242nm and 272nm respectively. The emission wavelength of quercetin and glycyrrhizin were obtained 515nm and 545nm respectively. The calibration curves for quercetin and glycyrrhizin were linear in the range from 10-70ng/ml and 100-600pg/ml respectively. The proposed methods were statistically validated and successfully applied in extracts. The limit of detection for glycyrrhizin and quercetin were found to be 0.28ng/ml and 4.65ng/ml respectively. The limit of quantification for quercetin and glycyrrhizin were found to be 0.83ng/ml and 14.11pg/ml respectively. The percentage recovery was found to be in the range of 98% and 101%.