Analysis of Medicines by Coulometric Titration. I. : Coulometric Titration of Sulfonamides

Abstract

Coulometric titration of several sulfonamides was studied utilizing a bromination with electrolytically generated bromine. The titration was carried out in an aqueous hydrochloric acid-potassium bromide medium. The end point was detected potentiometrically. Sulfanilamide, sulfaguanidine, xyloylsulfanilamide and sulfisomidine reacted with four atoms of bromine, while sulfathiazole, sulfisoxazole, sulfamerazine, sulfadimetoxine, and sulfamonometoxine reacted with six atoms of bromine. Commonly used sulfonamides tested gave satisfactory results in comparison with those obtained by the diazotization volumetric assay and by the alkalimetry for sulfisoxazole. This method of coulometric titration is simple, rapid, and precise, and is suitable for determining a small amount of sulfonamides.