Qualitative and quantitative analyses of ginkgo terpene trilactones by liquid chromatography/sonic spray ionization ion trap mass spectrometry

A liquid chromatography/sonic spray ionization mass spectrometry method (LC/SSI-MS) was developed for qualitative and quantitative analyses of ginkgo terpene trilactones. Five ginkgo terpene trilactones were successfully protonated for qualitative and quantitative analyses under the study conditions. The typical ion adducts were identified as (M + H)(+), (M + NH4)(+), and (M + Na)(+). The limits of detection were achieved between 2.5 and 10 ng with RSD of 0.173-4.82% and a linear range of 10-80 ng with R-2 = 0.991-0.999. This method was used to identify and quantify ginkgo terpene trilactones in extractions of ginkgo biloba leaves obtained from three different extraction methods. This is the first completely validated LC/MS method for quantification of ginkgo terpene trilactones. The factors that contributed to reduce the errors of identification and quantification of ginkgo terpene trilactones are systematically reported, and the advantages and disadvantages of LC/MS method in quantitative analysis are also discussed.