Simultaneous determination of nine coumarins in rat plasma by HPLC–MS/MS for pharmacokinetics studies following oral administration of Fraxini Cortex extract

A high performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS) method was developed for the simultaneous determination of nine coumarins including aesculin, aesculetin, fraxin, fraxetin, scopoletin, isoscopoletin, 6-hydroxy-7,8-dimethoxy coumarin, 8-hydroxy-6,7-dimethoxy coumarin and umbelliferone in rat plasma using nodakenin as the internal standard (IS). The plasma samples were pretreated by a one-step direct protein...