title: Stabilized analysis of antidepressant drugs by solvent-recycled liquid chromatography: procedure and proposed resolution mechanisms for chromatography.
abstract: In this efficient extraction and isocratic liquid-chromatographic procedure for measuring eight antidepressant drugs in serum (amoxapine, 8-hydroxyamoxapine, doxepin, desmethyldoxepin, imipramine, desipramine, amitriptyline, and nortriptyline), they are extracted from serum as a group by use of disposable solid-phase cyanopropyl columns; the eluate is injected directly onto a Zorbax cyanopropyl analytical column. This sample preparation circumvents potential problems of drug instability associated with the usual evaporating/concentrating techniques. Recycling the acetic acid/acetonitrile/n-butylamine mobile phase not only maintains a stable, cost-effective system, it also prolongs column life. Standard curves for all eight drugs are linear to 1000 micrograms/L; the detection limit is 8-10 micrograms/L. For all drugs and metabolites, within-run CVs were 0.9 to 2.2%, between-run CVs 2.1 to 3.8%. Analytical recovery of the solid-phase extraction step was 85 to 100% (mean = 94.5%) for all analytes. Standards and controls, stored frozen in drug-free serum, are stable for at least six months. We also report a study of separation mechanisms.
mesh_terms: D000929:Antidepressive Agents, Tricyclic / Q000097:blood* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005069:Evaluation Studies as Topic; D006801:Humans; D004364:Pharmaceutical Preparations / Q000097:blood; D012997:Solvents
chemical_list: D000929:Antidepressive Agents, Tricyclic; D004364:Pharmaceutical Preparations; D012997:Solvents