Spectrophotometric determination of sulfanilamides by a condensation reaction with p-dimethylaminocinnamaldehyde

p-Dimethylaminocinnamaldehyde has been proposed as a reagent for the spectrophotometric determination of sulfanilamides. This reagent was shown to undergo in acetonitrile a condensation reaction with sulfanilamide, Sulfamethoxypyridazine, Sulfachloropyridazine, Sulfamethoxazole, and Sulfamethazine to form colored products. Optimal reaction conditions were found. A procedure for the spectrophotometric determination of sulfanilamide compounds with detection limit n × 10−2 μg/mL was developed. Determination of Sulfamethoxazole and Sulfamethazine in pharmaceuticals was carried out.