Column Liquid Chromatography/Electrospray Ionization-Time of Flight-Mass Spectrometry and Ultraperformance Column Liquid Chromatography/Mass Spectrometry Methods for the Determination of Ginkgolides and Bilobalide in the Leaves of Ginkgo biloba and Dietary Supplements
Abstract Column liquid chromatography/electrospray ionization-time of flight-mass spectrometry (LC/ESI-TOF-MS) and ultraperformance column liquid chromatographic/MS (UPLC/MS) methods were developed for the determination of 5 terpenelactones in the leaves of Ginkgo biloba. The separation was performed using a C18 column and a mobile phase composed of water and acetonitrile. The limit of detection (LOD) values for ginkgolide J, ginkgolide C, ginkgolide B, and ginkgolide A were found to be in the range of 110 ng/mL by both methods, and the bilobalide LOD was 200 ng/mL by LC/ESI-TOF and 35 ng/mL by UPLC/MS. Using the optimized method, 4 commercial products were analyzed. Concentrations of total marker compounds in these products were in the 0.0915.4 range, with individual ginkgo terpenelactones being detected at ppb levels. LC/MS with ESI is described for the identification and quantification of ginkgolides and bilobalide in plant samples and dietary supplements that claim to contain G. biloba. These methods involve the use of the M NH4<sup/> and M H<sup/> ions of sesquiterpenoids in the positive ion mode with extractive ion monitoring by LC/ESI-TOF-MS and selected ion monitoring by UPLC/MS. The LC method coupled with MS analysis yielded well-separated peaks which resulted in a clear identification of the compounds.