Porous graphitic carbon chromatography/tandem mass spectrometric determination of cytarabine in mouse plasma

A high‐performance liquid chromatography (HPLC) system using a porous graphitic carbon (PGC) stationary phase interfaced with an electrospray ionization (ESI) source and a tandem mass spectrometer (MS/MS) for the analysis of cytarabine (ara‐C) in mouse plasma samples has been developed in support of a pharmacodynamic study. The graphitized carbon column was adopted for the separation of ara‐C and endogenous peaks from mouse plasma samples under the reversed‐phase phase mode in liquid chromatography. The retention characteristics of the PGC column and the ionization efficiencies of all analytes based on the experimental factors such as the composition of mobile phases were investigated. The potential of ionization suppression resulting from the endogenous biological matrices on the PGC column during HPLC/ESI‐MS/MS was investigated using post‐column infusion. The concentrations of ara‐C in mouse plasma obtained by using PGC‐HPLC/MS/MS and ion‐pairing HPLC/MS/MS were found to be in good agreement in terms of analytical accuracy. © 2007 John Wiley & Sons, Ltd.