title: Simultaneous determination of seven tricyclic antidepressant drugs in human plasma by direct-injection HPLC-APCI-MS-MS with an ion trap detector.
abstract: A sensitive and specific direct-injection high-performance liquid chromatography-atmospheric pressure chemical ionization tandem mass-spectrometry (HPLC-APCI-MS-MS) method has been developed for the rapid identification and quantitation of seven tricyclic antidepressants-amitriptyline, nortriptyline, doxepin, dosulepin, dibenzepin, opipramol, and melitracen-in human plasma. After the addition of the internal standard lofepramine and dilution with 0.1% formic acid, plasma samples were injected into the LC-MS-MS system. Proteins and other large biomolecules were removed during an on-line sample cleanup using an Oasis extraction column (1 x 50 mm, ID, 30 microm) with a 100% aqueous mobile phase at a flow rate of 4 mL/min. The extraction column was subsequently brought in-line with the analytical column by automatic valve switching. Analytes were separated on a 5-microm Symmetry C18 (Waters) analytical column (3.0 x 150 mm, ID) using a step gradient of acetonitrile-0.1% formic acid at a flow rate of 0.6 mL/min. The total analysis time was only 12 minutes per sample. The interday and intraday coefficients of variation for all compounds were </=11%. The assay was sufficiently sensitive to monitor all seven compounds within their therapeutic ranges. The proposed method has been in routine use for more than 1 year and permits direct analysis of plasma samples without time-consuming sample preparation, which may be especially advantageous for clinical laboratories.
authors.affiliation: Institute of Forensic Medicine, Karl-Franzens University Graz, Graz, Austria. manfred.kollroser@uni-graz.at
authors.forename: Manfred
authors.initials: M
authors.lastname: Kollroser
authors.forename: Caroline
authors.initials: C
authors.lastname: Schober
mesh_terms: D000929:Antidepressive Agents, Tricyclic / Q000097:blood*; D001274:Atmospheric Pressure; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000929:Antidepressive Agents, Tricyclic