Analysis of Flavonoids in Ginkgo Biloba Leaf Extract

Flavonoids are a type of polyphenol. Extensive research into their physiological action over recent years has confirmed their antioxidant effect.
An example of the analysis of flavonoids in ginkgo biloba leaf extract using the Prominence SPD-M20A photodiode array detector is introduced below.
Ginkgo biloba leaf extract is said to contain 20 kinds of flavonoids. Quercetin, kaempferol, and isorhamnetin were analyzed as three representative flavonoids. Fig. 1 shows the structural formula of these three components.

Fig. 1 Structural Formula

These flavonoids exhibit extremely high absorbance near 260 nm and 370 nm. Table 1 shows the analytical conditions and Fig. 2 shows the chromatogram for the standard solution.
The analyzed sample was a commercial supplement (in pill form) containing ginkgo biloba leaf extract. Fig. 3 shows the pretreatment procedure and Fig. 4 shows the chromatogram. Using a photodiode array detector allows a spectrum comparison with the standard sample for each component.

Fig. 2 Chromatogram of Standard Solution

Fig. 3 Sample Pretreatment Procedure

Fig. 4 Chromatogram of Supplement Containing Ginkgo Biloba Leaf Extract