Determination of tricyclic antidepressants by high-performance liquid chromatography

A method is described for the determination of amitriptyline, nortriptyline, imipramine and desipramine at low nanogram concentrations in serum. Separation and quantitation are performed by reversed-phase, isocratic, high-performance liquid chromatography utilizing ultraviolet detection at 210 nm. An internal standard, chloramitriptyline, is used as an aid to quantitation. Recovery of all four tricyclics is greater than 84%. The relative standard deviation for the analysis of amitriptyline, nortriptyline, imipramine and desipramine is less than 6% at a concentration of 100 ng/mL.