Sensitive Quantitative Determination of Chlorpromazine Metabolites

DIMETHYLAMINONAPHTHYL sulphonyl chloride (dansyl chloride) has been used in recent years as an end group analytical reagent in the study of protein structure 1 and in the determination of amino-acids 2–4 . Dansyl chloride reacts with primary and secondary amines and with phenolic hydroxyl groups 4 . Chlorpromazine, after administration to patients, yields over twenty known metabolites 5 . At least ten of these metabolites possess either an amino or a phenolic hydroxyl group, or both, as potential reactive sites for dansyl chloride coupling. We have studied the reactivity of dansyl chloride with the chlorpromazine metabolites listed in Table 1.