Objective: To establish a HPLC-MS/MS method for the determination of vitexin in rat plasma and its pharmacokinetics.
Methods: The HPLC-MS/MS method used Capcell Pak C18 column (50 mm x 2.0 mm I. D., 5 microm). The mobile phase was methanol and water (95:5, V/V, containing 0.1% formic acid) at a flow rate of 0.2 mL/min. Electrospray ionization (ESI) in negative ion mode and multiple reaction monitoring (MRM) was used for the quantification of vitexin with a monitored transitions m/z 431-->311 for vitexin and m/z 269-->225 for internal standard (I. S., emodin).
Results: Linear calibration curves were obtained over the concentration range of 0.5-2000 ng/mL (r = 0.9960) with the lowest limit of quantification (LLOQ) of 0.5 ng/mL. The recovery was in the range of 76.1%-89.0%. The relative standard deviations for the intra-day and inter-day validation were less than 11%.
Conclusion: The method is simple, accurate, fast, sensitive and suitable for the pharmacokinetic study of vitexin in rats.