Simultaneous determination of five flavonols in extract of Ginkgo biloba by high performance liquid chromatography

Objective To describe a high performance liquid chromatographic(HPLC) method to quantitate five flavonol components in the extract of Ginkgo biloba(EGb).Methods The five flavonols of EGb were extracted with 70% methanol and separated by passing through a kromasil C18 column(250×4.6 mm,5μm) at 40℃ with a step linear gradient using methanol∶0.1% formic acid at a flow rate of 1.0 ml/min.Results The limits of quantitation for rutin,quercitrin,quercetin,kaempferol and isorhamnetin were 0.03,0.02,0.008,0.006 and 0.005 mg/L,respectively.This method was linear over the concentration ranges of 2.02~50.5,1.932~48.3,2.01~50.4,0.49~12.3 and 0.39~9.8 mg/L respectively(r0.9992).The rates of recovery for the five components ranged 86.5%~99.2%,with the coefficient of precision being less than 2% within one day and less than 3% between two days.Conclusion The method is simple and accurate,and hence,can be validated as a means offering the basis for the quality control of flavonols in EGb.