A rapid and fully-automated method for the quantitation of tricyclic antidepressants in serum using turbulent-flow liquid chromatography-tandem mass spectrometry

Background: We describe a fully-automated turbulent-flow liquid chromatography-tandem mass spectrometry method for the detection of tricyclic antidepressant drugs (amitriptyline, desipramine, imipramine, and nortriptyline) in serum. Methods: Human serum and an internal standard were injected directly onto a Cyclone-P online solid-phase extraction (SPE) column (0.5 x 50 mm). Following removal of serum proteins and other components the analytes were transferred to a Hypersil Gold C-18 (50 x 3 mm) analytical column. Elution occurred with a gradient of water and acetonitrile each with 0.1% formic acid. Analytes were ionized and detected over a 3.5 min analysis time by electrospray-ionization mass spectrometry with selected reaction monitoring (SRM). Matrix effects were well-characterized and carryover, precision, linearity, recovery and limits of detection and quantitation were evaluated. Results: The simple and complex precision CVs for all compounds were <= 16%. The limits of detection and quantitation for all drugs were <= 3 ng/ml and <20 ng/ml, respectively. Recoveries were between 97 and 114%. Slopes for method comparison plots were all >0.96. Proficiency testing materials had values within 2 SDI of peer group means for all drugs. Conclusion: Based on validation data, this is a specific, sensitive fully-automated method for rapid quantitation of tricyclic antidepressants in serum. (C) 2010 Elsevier B.V. All rights reserved.