Quantification of positional double-bond isomers of ginkolic acid in Ginkgo Biloba and dietary supplements using GC/MS

Abstract

A GC/MS method focusing on the characterization and quantification of ginkgolic acids (GAs) in Ginkgo biloba L. plants, extracts and dietary supplements was developed. The analysis was performed on a HP-88 column. The GAs were derivatized with trimethylsulfonium hydroxide [(CH3)3SOH]. By using this technique, separation of 2 saturated (C13:0 and C15:0) and 6 unsaturated ginkgolic acid methyl esters with different positional double bonds (C15:1 Δ8 and Δ10, C17:1 Δ8, Δ10 and Δ12, and C17:2) was achieved. The developed GC/MS method was validated and the quantitation results were verified by comparison with a standard HPLC method. Nineteen G. biloba authenticated and commercial plant samples and 21 dietary supplements purported to contain G. biloba leaf extracts were analyzed. The presence of the marker compounds, terpene trilactones and flavonol glycosides, for Ginkgo biloba in the dietary supplements was determined by UHPLC/MS and used to confirm the presence of G. biloba leaf extracts in all of the botanical dietary supplements.