Oxidation of some pharmaceuticals containing nitrogen with sodium hypochlorite to yield cyanide ion

Ahmad NR and Rahman GN

Published on: 2024-03-15

Abstract

The reaction of some pharmaceuticals containing nitrogen with sodium hypochlorite was investigated under conditions that simulate wastewater disinfection. Initially, the reaction was studied in pure pharmaceuticals at concentrations of 1x10^-3 molar and a molar excess of sodium hypochlorite (5x10^-3M). This reaction was monitored using the spectrophotometric method for seven different compounds. The cyanide ion was detected in chlorhexidine-gluconate, metronidazole, frusemide, and chloramphenicol.  The largest formation was observed in chlorhexidine gluconate; the amount of cyanide ion formed increased to its maximum at 15–45 min. The formation of the cyanide ion was attributed to the formation of the dichloramine product by the oxidizing action of sodium hypochlorite, which decomposed into cyanide. The reaction studied in an industrial waste water sample from the state company for drug industries and medical appliances in Mosul, Iraq, was similar to the reaction noted.