Development and Application of a LC-MS/MS Method for the Determination of Fentanyl in Rat Plasma

In this study, a simple, rapid and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method is described for determination of fentanyl in rat plasma samples using sufentanil 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 Ac-quity BEH C18 column (2.1 mm 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 0.1-25 ng/mL for fentanyl in rat plasma. Only 2.0 min was needed for an analytical run. The method was applied to a pharmacokinetic study of fentanyl in rats.