Development and Validation of a Gas Chromatographic Method forIdentification and Quantification of Terpene Trilactones in Ginkgo bilobaL. Extract and Pharmaceutical Preparations

A gas chromatographic method was developed and validated for the determination of bilobalide and ginkgolides A, B, C and J in Ginkgo biloba L. The Ginkgo terpene trilactones have been dissolved in 57% of pure ethanol in purified water and separated by extraction with a mixture of toluene/ethyl acetate. After evaporation of the solvent with nitrogen and derivatization, these chemical markers have been quantified using GC-FID. The intra-day RSD was ranged from 1.13% for bilobalide to 2.34% in case of ginkgolides. The inter-day RSD was ranged from 2.54% and 3.68% for, bilobalide and ginkgolides respectively. Mean recoveries were 99.78% ± 0.82% and 99.48% ± 0.86% for ginkgolides and bilobalide, respectively. Based on chromatograms, the response of the terpene trilactones was linearly dependent on the terpene concentration, i.e. linear calibration curve was found in the range of the method and was applied to analyze standard extract (containing 5-7% total terpenoids and 22-25% total flavonoids) as working standard and for the analysis of six Ginkgo pharmaceutical products offered on the market.