Determination of Quercetin,Kaempferol,Isorhamnetin and Their Total Flavonol Glycosides in Ginkgo Biloba Extract Injection by HPLC

An HPLC method was established for the determination of quercetin,kaempferol,isorhamnetin and their total flavonol glycosides in Ginkgo Biloba extract injection and the quality evaluation of two brands.A Diamonsil C18 column was used with the mobile phase of methanol-0.4% phosphoric acid(55︰45) at the detection wavelength of 360 nm.Quercetin,kaempferol and isorhamnetin in the unhydrolyzed and hydrolyzed Ginkgo Biloba extract injection showed good separation and linearity ranges.The average recoveries of quercetin,kaempferol and isorhamnetin in the unhydrolyzed and hydrolyzed samples were 100.2%,100.3%,100.2% with RSDs of 0.64%,1.14%,0.40%,and 100.0%,100.7%,100.3% with RSDs of 0.79%,0.98%,1.00%,respectively.