Measurement of maprotiline and oxaprotiline in plasma by high-performance liquid chromatography of fluorescent derivatives.

The antidepressant maprotiline and its hydroxylated analogue oxaprotiline were assayed in plasma by solvent extraction and formation of fluorescent derivatives, which were purified by thin-layer chromatography and quantitated by high-performance liquid chromatography with fluorescence monitoring. The procedure possesses a high sensitivity, accuracy and reproducibility, and metabolites of the drugs did not interfere.