Abstract:

Objective To propose a method to determine the total flavonoid in leaves of Acer truncatum Bunge by Spectrofluorimetry. Methods Based on fluorescent property that flavonoids can make a stable complexation with Al³⁺, the excitation and emission wavelengths were selected at 470 nm and 547 nm respectively with rutin as the standard sample to research effects of solvent, the dosage of 5%Al(NO₃)₃ solution, pH, standing time and chlorogenic acid. Results The optimum conditions were 60% ethanol as solvent, added 1 mL of 5%Al(NO₃)₃ solution and made pH=5 in 10 mL volumetric flask. The fluorescence intensity had a good linear relationship with rutin concentration in the range of 6.55×10^-6mol/L~3.20×10^-5mol/L. The regression equation was found to be y=1.147 7x + 0.430 4,R²=0.999 1. Conclusion This method could lower the influence of chlorogenic acid for determination total flavonoid by changing the excitation wavelength with fluorescence analysis and the work provided a reference for quantitative analysis of total flavonoid in the leaves of Acer truncatum Bunge.

Key words: leaves of Ace truncatum Bunge, total flavonoid, determination, spectrofluorimetry