Development of nanoelectrospray mass spectrometry technique for simultaneous detection of active and toxic components in ginkgo products

A negative ionization nanoelectrospray ionization mass spectrometry technique was developed for the simultaneous detection of both active and toxic components in ginkgo products. This technique dramatically simplified the analytical procedures for ginkgo analysis. Unlike the conventional methods that hydrolyze flavonol glycosides to flavonoids for analysis, this technique detects intact flavonol glycosides directly, enabling these natural glycosides to be differentiated from the synthetic flavonoids. Fingerprinting of 14 commercial ginkgo products using this technique revealed large variations between brands. Three products showed evidence of fortification with synthetic surrogates. This method was also used to quantify these compounds in the 14 different commercial ginkgo extracts. Two products were found to contain toxic ginkgolic acids that exceeded the 5 mug/g limit by as much as 50000--90000-fold. These results emphasize the importance of appropriate monitoring of ginkgo product quality. This technique is potentially useful for analysis of other complex mixtures.