Abstract: Objective Quantification and pharmacokinetics of phencynonate were investigated in rat by the method of high-performance liquid chromatographic assay with electro spray ionization mass spectrometry detection(LC-ESI-MS).Methods The chromatography was on BetaBasic-18 column(150mm×2.1mm id,3μm).Mass spectrometric measurements were performed on ion-trap mass spectrometer equipped with ESI source working in positive ion mode.Results The linearity was obtained over the concentration range of 1～100μg/L in rat blood.The lower limit of quantification was at 1μg/L in blood.Extraction recoveries were in the range of 69.6%～79.1%.The concentration-time curves in rats were all best fitted to first order Absorption two-compartments open model after a single dose phencynonate(0.35mg/kg) intramuscularly.The main pharmacokinetic parameters of phencynonate were as follows:t_1/2α 0.679h,t_1/2β 3.98h,t_1/2Ka 0.013h,t_max 0.076h,C_max 54.1μg/L,AUC 77.7(ng·h)/mL.Conclusion The method is simple,sensitive and specific.It is successfully applied for quantification of phencynonate and for the clinic drug monitoring and the pharmacokinetic studies.

Key words: phencynonate, liquid chromatography assay with electro spray ionization mass spectrometry detection, quantifi-cation, pharmacokinetics