[Assay of clomipramine and its demethylated derivative by liquid chromatography]

Clomipramine and desmethylclomipramide are determined on 1 ml of human blood plasma, after extraction with hexane and high-performance liquid chromatography using a cyanopropyl silane column and UV detection at 280 nm. Imipramine and desipramine are used as internal standards. The methods allow detection limits of 5 micrograms/l; 15.9 nmol/l (clomipramine) to 10 micrograms/l; 33.2 nmol/l (desmethylclomipramine). The precision of the method at clomipramine concentrations of 0.05 to 0.2 mg/l was indicated by a coefficient of variations less than 6% for clomipramine and less than 7% for desmethylclomipramine.