Rapid liquid chromatography–tandem mass spectrometry method for quantification of ziprasidone in human plasma

A liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for the determination of ziprasidone (ZIP) in human plasma was developed. ZIP and N ‐methyl ziprasidone as internal standard (IS) were extracted from alkalinized plasma using tert‐ butyl methyl ether. Separation was performed isocratically on a C8 column with 90% acetonitrile containing 2 mmol/L ammonium acetate as a mobile phase with a total run time of 2.5 min. MS/MS transitions of m / z 413 → 194 and m / z 427 → 177 of the analyte and internal standard were used for quantification. Confirmatory ions of m / z 413 → 177 and m / z 427 → 180 were collected as well. The calibration curve based on peak‐area ratio was linear up to at least 200 ng/mL with a detection limit of 0.1 ng/mL. The method showed satisfactory reproducibility with a coefficient of variation of less than 5%. The method was successfully applied to the analysis of ZIP in spiked human plasma. Copyright © 2005 John Wiley & Sons, Ltd.