Development and Validation of an LC-ESI-MS/MS Method for Simultaneous Determination of Ligustroflavone and Rhoifolin in Rat Plasma and Its Application to a Pharmacokinetic Study.

A selective and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the simultaneous determination of ligustroflavone and rhoifolin in rat plasma. Chromatographic separation was performed on a Venusil HILIC column using an isocratic mobile phase consisting of acetonitrile/water/formic acid (75:25:0.1, v/v/v). The detection was achieved using a triple-quadrupole tandem MS in negative ionization through selected reaction monitoring (SRM) mode. The calibration curves of both analytes in plasma showed good linearity over the concentration ranges of 3-300 ng/mL for ligustroflavone, and 2-200 ng/mL for rhoifolin. This assay was used to investigate the pharmacokinetics of ligustroflavone and rhoifolin in rats.