荧光分析法测定元宝枫叶中总黄酮含量的研究

目的 采用荧光分析方法,对元宝枫叶总黄酮含量进行测定研究.方法 以芦丁为标准对照品,利用黄酮与Al3＋形成稳定荧光络合物的性质,选择激发波长λex=470 nm,发射波长λem=547 nm,研究乙醇的体积分数、5%Al（NO3）3的加入量、pH、放置时间以及绿原酸对荧光强度的影响.结果最佳测定条件是以60%乙醇溶液作为溶剂,在10 mL的容量瓶中加入1 mL 5% Al（NO3）3,并使测定溶液pH=5.该方法测定芦丁质量浓度在6.55×10-6mol/L～3.20×10-5mol/L与荧光强度具有良好的线性关系,且回归方程为y=1.147 7x ＋ 0.430 4,R2=0.999 1.结论 采用荧光分析法,通过改变激发光的波长,能够减小绿原酸对黄酮测定的干扰,可作为元宝枫叶总黄酮含量测定的参考方法.

Determination of total flavonoid in leaves of acer truncatum Bunge by spectrofluorimetry

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.