Sensitive liquid chromatographic-tandem mass spectrometric method for the determination of fluoxetine and its primary active metabolite norfluoxetine in human plasma.
A sensitive method for the simultaneous determination of fluoxetine and its major active metabolite norfluoxetine in plasma was developed, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted from alkalised plasma with hexane-isoamyl alcohol (98:2, v/v) followed by back-extraction into formic acid (2%). Chromatography was performed on a Phenomenex Luna C18 (2) 5 microm, 150x2 mm column with a mobile phase consisting of acetonitrile-0.02% formic acid (340:660, v/v) at a flow-rate of 0.35 ml/min. Detection was achieved by a Perkin-Elmer Sciex API 2000 mass spectrometer (LC-MS-MS) set at unit resolution in the multiple reaction monitoring mode. TurbolonSpray ionisation was used for ion production. The mean recoveries for fluoxetine and norfluoxetine were 98 and 97%, respectively, with a lower limit of quantification set at 0.15 ng/ml for the analyte and its metabolite. This assay method makes use of the increased sensitivity and selectivity of mass spectrometric (MS-MS) detection to allow for a more rapid (extraction and chromatography) and sensitive method for the simultaneous determination of fluoxetine and norfluoxetine in human plasma than has previously been described.
Sutherland
F C
FC
FARMOVS Research Centre for Clinical Pharmacology and Drug Development, University of the Free State, Bloemfontein, South Africa. gnfmfcws@frm.uovs.ac.za
Badenhorst
D
D
de Jager
A D
AD
Scanes
T
T
Hundt
H K
HK
Swart
K J
KJ
Hundt
A F
AF
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005473:Fluoxetine / Q000031:analogs & derivatives / Q000097:blood*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017367:Selective Serotonin Reuptake Inhibitors / Q000097:blood*
D005473:Fluoxetine; D017367:Selective Serotonin Reuptake Inhibitors; C036139:norfluoxetine