A liquid chromatography–tandem mass spectrometry method for the quantification of PAC-1 in rat plasma

A sensitive and specific liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of PAC-1 in rat plasma. After extraction with ethyl acetate, the chromatographic separation was carried out on an ACQUITY UPLC™ BEH C 18 column, with acetonitrile and water (39:61 (v/v) both containing 0.1% formic acid) as mobile phase at a flow rate of 0.20 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source. The calibration curve was linear over the range of 10–1500 ng/mL ( r > 0.99). The LOQ was evaluated to be 0.3 ng/mL. The method described herein is sensitive, selective and faster than other existing method, and was successfully applied to the pharmacokinetic study and gender difference investigation of PAC-1 after oral administration in rats.