A simple high-performance liquid chromatography method for the quantitation of tricyclic antidepressant drugs in human plasma or serum

Objective: A simple reversed-phase high performance liquid chromatography m ethod with a variable wavelength detection has been developed for determini ng the commonly used tricyclic antidepressant drugs in plasma. Methods: The assay procedure involves a liquid-liquid extraction with an initial extrac tion into hexane:ethyl acetate after basification of the homogenate, The co lumn used was a Supelco Hypersil 5 mum, 150 x 3.2 mm, The mobile phase was acetonitrile, methanol, and phosphate buffer (0.01 M, pH 7.4) at 12:3:5 rat io (v/v/v), Results: The recoveries ranged from 89 to 108% and the day-to-d ay precision was 1.1 to 13% CV depending on the compound. The method is sen sitive to 15 ng/mL and linear to 400 ng/mL with a 25 muL injection. Conclus ion: This method is simple, sensitive, precise, inexpensive, and is current ly used in our laboratory for therapeutic monitoring of tricyclics. The dat a generated by this method were within the range outlined by the College of American Pathologists.