Development of an alternative method for determination of terpene lactones in ginkgo dry extract

A new liquid chromatographic mass spectrometric (LC-MS) method for determination of terpene lactones in ginkgo dry extract has been developed. The new method has several advantages over the existing European Pharmacopoeia (Ph. Eur.) method for analysis of terpene lactones in ginkgo dry extract, the major ones being a very simple sample pre-treatment and an excellent selectivity. 5 terpene lactones were analysed with a precision expressed as relative standard deviation (RSD) of 0.4-3.1% and a mean relative error (RE) within +/-4.6%. The method was used to analyse 9 samples of ginkgo dry extracts from 3 different extract producers. The content of bilobalide was found to be in the range of 2.6-3.4% in all samples, whereas the sum of ginkgolides A, B and C was found to be in the range of 3.0-3.6%. Ginkgolide J was found in the range of 0.3-0.6%.