title: On-line solid-phase extraction and high-performance liquid chromatographic determination of nortriptyline and amitriptyline in serum.
abstract: An isocratic reversed-phase high-performance liquid chromatographic method with on-line solid-phase extraction for the simultaneous determination of amitriptyline and nortriptyline in serum has been developed. A 250-microliters serum sample is injected directly onto a commercially available CN cartridge and, after a washing step, the retained solutes are backflushed onto a bonded-phase CN column using a column-switching technique and a mobile phase composed of acetonitrile (26%) and 0.05 M phosphate buffer with diethylamine. Serum is diluted with 0.1 M sodium lauryl sulphate and centrifuged before the injection. Detection at 210 nm ensures sufficient sensitivity. The recovery is almost quantitative and the relative standard deviation ranges from 2.8 to 8.0% for concentrations of 200-40 ng/ml. Being rapid and simple, the method is convenient for routine use.
authors.affiliation: University Hospital Motol, Department of Anaesthesiology and Resuscitation, Prague, Czechoslovakia.
authors.forename: M
authors.initials: M
authors.lastname: Dolezalová
mesh_terms: D000639:Amitriptyline / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D009661:Nortriptyline / Q000097:blood*
chemical_list: D000639:Amitriptyline; D009661:Nortriptyline