Study on the determination method of total flavonoids in ginkgo biloba extract

A simple and sensitive new method for the determination of total flavonoids in ginkgo biloba extract was put forth.The experimental results indicated that the fluorescence intensity of ginkgo biloba extract(GBE) was greatly enhanced by heating in an acid medium and forming a complex with Al3+.A fluorimetric method for determination of total flavonoids in GBE was proposed by taking quercetin as the standard sample.Under the optimum conditions,a linear relationship was obtained between the fluorescence intensity and the concentration of quercetin in the range of 0.000 75～0.50 μg/mL(R=0.999 9; P0.000 1),and the detection limit was 0.45 ng/mL(S/N=3).This method was applied for determining the total flavonoids in GBE,the recovery test was put forth by the standard addition method,and the expected results were obtained.