Fluorophotometric Determination of Total Glucoside of Paeony in Radices Paeoniae Alba Based on Alkali Hydrolysis

Based on the hydrolysis of total glucosides of paeony (TGP) of radices paeoniae alba in 50 g·L-1 NaOH solution to give benzoic acid and on the fluorescence property of the benzoic acid produced as shown by its fluorescence spectrum at the wavelengths of 280 nm (λex) and 310 nm (λem) in an acetate buffer medium of pH 2.72,a fluorophotometric method for determination of TGP in radices paeoniae alba was proposed.Linear relationship was found between values of ΔF(F0-F) measured at the wavelengths mentioned above and concentration of benzoic acid in the range of 1.0-10.0 mg·L-1.The proposed method was used in the analysis of samples of radices paeoniae alba,giving values of recovery ranged from 92.5%-103.0%,and of RSD (n=6) of 3.73%.