Rapid isothermal gas--liquid chromatographic determination of tricyclic antidepressants in serum with use of a nitrogen-selective detector.

A rapid and simple gas--liquid chromatographic method suitable for routine use is described for quantitation of tricyclic antidepressants. The method can be used for quantitation of amitriptyline, nortriptyline, imipramine, desmethylimipramine, doxepin, desmethyldoxepin, clomipramine, desmethylclomipramine, trimipramine, desmethyltrimipramine and dibenzepine. The method involves one extraction with hexane--isopropyl alcohol, no derivative formation of the metabolites and chromatography using an OV-25 liquid phase which permits isothermal quantitation of the different drugs within 5--10 min. Standard curves for the different tricyclic antidepressants were linear over the concentration range tested (10--1500 micrograms/l) and the maximum coefficient of variation was 7.7%.