Determination of nifedipine in human serum by HPLC-MS/MS

Aim To develop and validate an HPLCMS/MS for the determination of nifedipine in human serum.Methods Nitrendipine was added as an internal standard.The sample preparation included a simple deproteinization step with methanol.Chromatographic separation was achieved on a Kromasil C18 column(4.6mm×150mm,5μm) at 30℃ with the mobile phase consisted of methanol-H2O(90:10,V/V).The mobile phase was eluted at a flow rate of 0.5 mL ·min-1.Tandem mass spectrometer equipped with electrospray ionization source was applied and operated in the negative ion mode.Multiple reaction monitoring using the precursor to produce on combinations of m/z 345.1/122.0 and m/z 359.2/122.0 was performed to quantify nifedipine and nitrendipine,respectively.Results The calibration curves were linear over the range of 0.5μg·L-1～50μg·L-1(r=0.9987).RSD of intra-batch and inter-batch were less than 15%,extraction recovery of three level concentrations were between 64.06%～77.10%.Conclusion The method is shown to be convenient,accurate,sensitive,and suitable for clinical pharmacokinetic study of nifedipine.