Simultaneous determination of limonin, dictamnine, obacunone and fraxinellone in rat plasma by a validated UHPLC–MS/MS and its application to a pharmacokinetic study after oral administration of Cortex Dictamni extract

A rapid and selective ultra high performance liquid chromatography–tandem mass spectrometry method was developed for the simultaneous determination of four major ingredients in Cortex Dictamni extract, including limonin, dictamnine, obacunone and fraxinellone in rats plasma. Nimodipine was used as the internal standard. Following extraction by methyl tert-butyl ether, the analytes were separated on a Thermo Syncronis C18 column by a gradient...