title: Quantitative determination of tricyclic antidepressants and their metabolites in plasma by solid-phase extraction (Bond-Elut TCA) and separation by capillary gas chromatography with nitrogen-phosphorous detection.
abstract: An analytical method for the simultaneous determination of amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, and desmethylclomipramine in human plasma using promazine as internal standard is described. The method is based on a solid-phase extraction procedure using the Bond-Elut TCA columns followed by separation and detection using capillary gas chromatography with a specific nitrogen phosphorous detector (GC/NPD). Using the new extraction procedure, the problem of adsorption losses was overcome, and good recoveries were achieved for all compounds tested (>87%). Furthermore, clean extracts free of chromatographic interferences were obtained. Complete separation of underivatized, tricyclic antidepressant compounds was achieved in <11 minutes with reliable chromatographic performance. The limits of detection ranged from 1.2 to 5.8 microg/l. Calibration curves, showing good linearity, were prepared covering the therapeutic concentrations range expected (20 to 500 microg/l). The interassay precision values (RSD) ranged from 4.5% to 9.8%. It is concluded that extraction of amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, and desmethylclomipramine, with Bond Elut TCA solid-phase columns followed by their detection using GC/NPD provides a sensitive and reproducible method that can be easily automated for immediate and routine analysis of clinical samples.
authors.affiliation: Department of Pharmacology, Institut Municipal dInvestigació Médica, Autonomous University of Barcelona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: de la Torre
authors.forename: J
authors.initials: J
authors.lastname: Ortuño
authors.forename: J A
authors.initials: JA
authors.lastname: Pascual
authors.forename: S
authors.initials: S
authors.lastname: González
authors.forename: J
authors.initials: J
authors.lastname: Ballesta
mesh_terms: D000639:Amitriptyline / Q000097:blood; D000929:Antidepressive Agents, Tricyclic / Q000097:blood*; D002849:Chromatography, Gas / Q000379:methods; D002997:Clomipramine / Q000031:analogs & derivatives / Q000097:blood; D003891:Desipramine / Q000097:blood; D016903:Drug Monitoring / Q000379:methods* / Q000706:statistics & numerical data*; D006801:Humans; D007099:Imipramine / Q000097:blood; D016014:Linear Models; D009661:Nortriptyline / Q000097:blood; D011395:Promazine / Q000097:blood; D012680:Sensitivity and Specificity
chemical_list: D000929:Antidepressive Agents, Tricyclic; C012273:desmethylclomipramine; D000639:Amitriptyline; D009661:Nortriptyline; D002997:Clomipramine; D011395:Promazine; D007099:Imipramine; D003891:Desipramine