Determination of timiperone in rat plasma by high-performance liquid chromatography with electrochemical detection

We report a sensitive new method for the determination of timiperone in rat plasma by using high-performance liquid chromatography with electrochemical detection. The method involves extraction of plasma samples with heptane-isoamyl alcohol at pH > 8, followed by back-extraction into dilute acetic acid. Separation was accomplished by reversed-phase high-performance liquid chromatography on an ODS column with the mobile phase consisting of 0.1 M phosphate buffer (pH 3.5)-acetonitrile-methanol (65:20:15, v/v). Recovery was greater than 80%. Calibration curve was linear over the concentration range 0.5-50.0 ng/ml. The limit of quantitation of timiperone was 0.5 ng/ml plasma.