Selective dissolution and one step separation of terpene trilactones in ginkgo leaf extracts for GC-FID determination

Under ultrasonication, the ginkgo terpene trilactones, ginkgolides and bilo balide, in ginkgo extracts can be selectively dissolved in 10% aqueous NaH2 PO4 solution at a temperature of 50-60 degreesC and separated from the solu tion by extraction with a mixture of ethyl acetate/tetrahydrofuran in a cap ped vial. After derivatization. these terpene trilactones can be quantified using GC-FID. This method has a detection limit of 10 ng, and the RSD was 6% (n = 5). Twelve commercial GEE products in powder, liquid, tablet and ca psule forms were analyzed. The total time required for analyzing these samp les from sample preparation to final data processing was less than 6 h, and the total organic solvent consumption was less than 40 ml. This procedure proves to be a simple. fast, safe, and effective method for all types of Gi nkgo biloba extracts (GBE) including the "complex" or "advanced" formulas. (C) 2001 Elsevier Science B.V. All rights reserved.