Simultaneous determination of five free and total flavonoids in rat plasma by ultra HPLC–MS/MS and its application to a comparative pharmacokinetic study in normal and hyperlipidemic rats

A simple and rapid ultra-high performance liquid chromatography–tandem mass spectrometry (uHPLC–MS/MS) method has been developed for the simultaneous determination of five free flavonoids (amentoflavone, isorhamnetin, naringenin, kaempferol and quercetin) and their total (free and conjugated) forms, and to compare the pharmacokinetics of these active ingredients in normal and hyperlipidemic rats. The free and total forms of these flavonoids were...