Abstract: A new method for the determination of quercetin in Ginkgo leaves tablets was established by sodium dodecyl sulfate (SDS) enhanced fluorimetry.The effects of external conditions,such as the type and amount of surfactant and pH on the fluorescence intensity of quercetin were investigated.Results show that among the four kinds of ordered media,i.e.,SDS,CTMAB,Triton X-100 and β-CD,the fluorescence intensity of quercetin is greatly enhanced in SDS solution under alkaline condition (pH=9.12) with a strong fluorescence emission peak at λ_ex/λ_em=464/542 nm.Under the optimal experimental conditions of pH=9.12 and SDS concentration of 1.5×10^-2 mol/L the linear relationship between fluorescence intensity and concentration of quercetin is kept in the range of 2-14 μg/mL with the detection limit of 0.16 μg/L and RSD of 1.56%.The method has been applied to the determination of quercetin in four kinds of Ginkgo leaves tablets with satisfactory results.

Key words: sodium dodecyl sulfate, fluorimetry, quercetin, Ginkgo leaves tablets