Determination of Linezolid in Rat Plasma by Ultra Performance Liquid Chromatography Tandem Mass Spectrometry

In this study, a simple, rapid and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method is described for determination of linezolid in rat plasma samples using diazepam as the internal standard (IS) from pharmacokinetic assays. Sample preparation was accomplished through a simple protein precipitation with acetonitrile, and chromatographic separation was performed on an Acquity BEH C18 column (2.1 x 50 mm, 1.7 mu m) with gradient profile at a flow of 0.4 mL/min. The linearity of this method was found to be within the concentration range of 10-10000 ng/mL for linezolid in rat plasma. Only 3.0 min was needed for an analytical run. The method was applied to a pharmacokinetic study of linezolid in rats.