Study on Extracting Flavonoids from the Leaves of Ginkgo Biloba by Ultrasonic

The extraction processes of flavonoids with Ultrasonic were studied. The extracting congditions of flovonoids from the Leaves of Ginkgo Biloba were optimized by orthogonal design. Spectrophotometry was used to determine the content of flavonids. The results show the optimum extraction technique was following: the solid-liquid ratio is 1 15,ultrasonic power is 160 W,the temperature is 35 degrees and ethanol is 65%,the measurements were carried out on four parallel experiments. Extraction can be achieved for 10 minutes two times. The content of flavonoids extract by ultrasonic is accounted for 93. 65% of total flavonoids in Ginkgo biloba.