A polarographic method for the determination of the N-oxide, N-oxide-sulphoxide and sulphoxide metabolites of chlorpromazine

Cathode ray polarography has been used to measure chlorpromazine-N-oxide, N-oxide sulphoxide and chlorpromazine sulphoxide in mixtures. The response was linear when the metabolites were present in the range 10^?5 to 5 times 10^?8m in aqueous solutions. Reductive polarography of the mixed oxides in solution gave an additive wave from which individual oxides were determined by subtraction. Ultraviolet and Potentiometrie titration methods were used to determine the pKa values of the oxide metabolites of chlorpromazine. The mechanism of the reduction process was investigated using d.c. polarography and preparative micro-electrolysis. Polarographic analysis was applied to the determination of the metabolites after their separation from urine, plasma and microsomal preparations.