Comparison of Two On-Line Analysis Techniques Used for the Screening of Antioxidants in EGb 761

Abstract

In order to perform on-line screening procedures for antioxidants in the Ginkgo biloba extract (EGb761), a comparison was carried out between LC–DAD–DPPH analysis used for the determination of DPPH· bleaching and LC–DAD–CL determination applied for the detection of H2O2 and O 2 −· scavenging activities. The results demonstrated that 15 antioxidants in EGb 761 could be identified by LC–DAD–CL, while only 10 antioxidants were detected under LC–DAD–DPPH conditions. Furthermore, it was found that both sensitivity and reproducibility of the LC–DAD–CL method were superior. The results indicated that the combination of the two methods might provide useful information for the prediction of antioxidants in herbal medicines.