Determination of duloxetine in human plasma by capillary electrophoresis with laser-induced fluorescence detection

摘要

A method based on capillary electrophoresis has been developed for the analysis of the novel antidepressant drug duloxetine in human plasma. The method makes use of laser-induced fluorescence detection after derivatisation of the analyte with 5-(4,6-dichlorotriazinyl)aminofluorescein at pH 11. A single step liquid/liquid extraction procedure with a mixture of hexane/2-propanol allows the sample clean-up with extraction yields always >= 84% and interference removal. The electrophoretic separation is achieved using uncoated fused silica capillaries (60.0 cm effective length, 75.0 cm total length, 50 mu m internal diameter) and a background electrolyte composed of borate buffer (40mM, pH 10.3), tetrabutylammonium bromide (10 mM), and acetone (10%, v/v). The applied voltage is 20 kV; the samples are injected by pressure (50 mbar x 8 s). The method has been fully validated in terms of linearity range (2.5-150 ng mL(-1)), LOD and LOQ(1.0 and 2.5 ng mL(-1), respectively), precision (R.S.D. < 6.7%) and accuracy (recovery > 78%). Application to samples obtained from patients under treatment with duloxetine gave good results. The method represents the first application of capillary electrophoresis to the analysis of duloxetine in human plasma. (C) 2009 Elsevier B.V. All rights reserved.