title: Liquid chromatography-atmospheric pressure chemical ionisation/mass spectrometry: a rapid and selective method for the quantitative determination of ginkgolides and bilobalide in ginkgo leaf extracts and phytopharmaceuticals.
abstract: In order to evaluate the composition of active constituents in phytopharmaceutical preparations, valid analytical methods are required. For the determination of the active terpene constituents of Ginkgo biloba (the ginkgolides and bilobalide), a liquid chromatography-mass spectrometry (LC-MS) method has been developed using atmospheric pressure chemical ionisation (APCI) in the negative ion mode. This detection mode was found to be much more sensitive and selective compared to UV; indeed the ginkgo terpene trilactones lack strong UV chromophores and flavonoids interfere with their UV detection. LC-APCI/MS detection allowed a considerable reduction in analysis time when compared to LC-UV, because LC resolution was only needed between the pair of isomers ginkgolide B and ginkgolide J. All compounds were selectively detected by single ion monitoring of their specific deprotonated molecules [M-H]-. The samples were directly injected without pre-purification, and a fast gradient was applied, reducing the total time of analysis to 14 min. With this method, the ginkgo terpene trilactones were detected on-line in the picogram range. Several commercial ginkgo preparations on the Swiss market were analysed, and the ginkgolide and bilobalide contents were evaluated using the method described.
authors.affiliation: Université de Lausanne, Institut de Pharmacognosie et Phytochimie, BEP, CH-1015 Lausanne, Switzerland.
authors.forename: Anette Gemal
authors.initials: AG
authors.lastname: Jensen
authors.forename: Karine
authors.initials: K
authors.lastname: Ndjoko
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Wolfender
authors.forename: Kurt
authors.initials: K
authors.lastname: Hostettmann
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Camponovo
authors.forename: Fabio
authors.initials: F
authors.lastname: Soldati
mesh_terms: D001274:Atmospheric Pressure; D002853:Chromatography, Liquid / Q000379:methods*; D003517:Cyclopentanes / Q000032:analysis*; D004224:Diterpenes; D005663:Furans / Q000032:analysis*; D020441:Ginkgo biloba / Q000737:chemistry*; D046934:Ginkgolides; D007783:Lactones / Q000032:analysis* / Q000302:isolation & purification; D013058:Mass Spectrometry / Q000379:methods*; D015394:Molecular Structure; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013729:Terpenes / Q000302:isolation & purification; D013997:Time Factors
chemical_list: D003517:Cyclopentanes; D004224:Diterpenes; D005663:Furans; D046934:Ginkgolides; D007783:Lactones; D010936:Plant Extracts; D013729:Terpenes; C045856:ginkgolide B; C073710:bilobalide