Simultaneous determination of naringin, hesperidin, neohesperidin, naringenin and hesperetin of Fractus aurantii extract in rat plasma by liquid chromatography tandem mass spectrometry.

A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of naringin, hesperidin, neohesperidin, naringenin and hesperetin in rat plasma, using liquiritin as the internal standard. Plasma samples extracted with a solid-phase extraction procedure were separated on a Zorbax SB-C18 analytical column (2.1 mm × 150 mm, 5 μm) and detected by electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The calibration curves were linear over the range of 3.0-600 ng/ml for naringin, 0.5-100 ng/ml for hesperidin, 3.5-700 ng/ml for neohesperidin, 5.0-1000 ng/ml for naringenin and hesperetin, respectively. The lower limits of quantification were 0.5 ng/ml for naringin, hesperidin, naringenin and hesperetin, and 0.35 ng/ml for neohesperidin. Intra- and inter-day precision (RSD%) was less than 15% and accuracy (RE%) ranged from -3.3% to 4.8%. The validated method was successfully applied to investigate the pharmacokinetics of the major flavanones of Fructus aurantii extract after oral administration to rats.