Rapid microwave-assisted hydrolysis for determination of ginkgo flavonol glycosides in extracts of Ginkgo biloba leaves

A rapid microwave-assisted hydrolysis (MAH) method is presented for the sample pretreatment of the determination of ginkgo flavonol glycosides in extracts of Ginkgo biloba L. (EGb). By this method, flavonol glycosides can be completely hydrolyzed within 2 min. After investigating the effects of solvents, acidity, microwave power, and microwave radiation time on hydrolysis, the optimal hydrolysis conditions are as follows: 300 W of microwave power, 2 min of hydrolysis time, 5.7% of hydrochloric acid in the hydrolysis solution, and n-propanol as the hydrolysis solvent. After MAH of the samples, three flavonol aglycones, such as quercetin, kaempferol, and isorhamnetin are analyzed by high-performance liquid chromatography. Compared with conventional reflux hydrolysis, this method owns offers several advantages: it saves time, costs less, and is environmentally friendly.