QuantitativeDeterminationof ChiorpromazineMetabolitesin Urine

A simple, rapid, precise, and accurate method is described for the simul-taneous and quantitative determination of conjugated and unconjugated chlorpromazine metabolites in urine. It depends on reduction of sulf-oxides to sulfides, and oxidation of sulfides to ion radicals in a solution of Fe-I-a (lO-N) in l8N H2S04.Absorbance is measured at 422, 530, 565, and 700 nm, and concentration of metabolites is calculated by substituting values obtained in appropriate equations. Our data for urines (from schizophrenic men chronically medicated with chlorpromazine) generally agree with those of other workers. Additional Keyphrases conjugated and unconjugated metabolites #{149} sulfoxide reduction to sulfide #{149} ion radical formed in H2S04-Fe #{149} excretion by schizo-phrenic men T HE BEST METHOD for determining cpz ’ and its metabolites in human urine is that of Bolt ci al. (1), in which conjugated metabolites are separated from nonconj ugated metabolites, then each is reacted with sulfuric acid to produce a colored reaction mixture, the absorbance of which is measured at 400, 530, or 565 and 700 nm and corrected for background color caused by urinary pigments. The amount of metabolite is calculated by comparing the corrected A with that of a pure known. The method is not widely used, probably because color development varies with the com-pound used as standard under the conditions recommended, and because recoveries of the con-jugated metabolites from the ion-exchange resin also vary. We have modified and improved this method