Rapid quantitative analysis of oxiracetam in human plasma by liquid chromatography/electrospray tandem mass spectrometry

A rapid and accurate reversed-phase liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantitative determination of oxiracetam in human plasma. After addition of internal standard (piracetam) plasma was precipitated with two volumes of acetonitrile and the supernatant was evaporated. The residues were dissolved in 0.1% acetic acid and analyzed by reversed-phase HPLC with the detection of the analyte in the multiple reaction monitoring (MRM) mode. This method for the determination of oxiracetam was accurate and reproducible, with a limit of quantitation of 0.2 mug/ml in human plasma. The standard calibration curve for oxiracetam was linear (r(2) = 0.999) over the concentration range 0.2-40.0 mug/ml in human plasma. The intra- and inter-day precision over the concentration range of oxiracetam was lower than 8.3% (relative standard deviation, %R.S.D.), and accuracy was between 92.5-106.4%. (C) 2004 Elsevier B.V. All rights reserved.