Determination of chloramines in aqueous solutions. The NCl3 sensor

Reactions of sodium chlorate (I) and NH4+ carried out in aqueous solutions produce mono-, di- and trichloramine. The stability of the products of this reaction is strongly pH and time dependent. Electrochemical properties of chloramines have been investigated and compared with their spectrophotometr ic behaviour. Mono- and dichloramine are reduced at Pt electrodes in single , irreversible peaks. The electrode processes of NCl3 occur in the region o f Cl- oxidation, and the whole system behaves reversibly. The formation of NCl3 has been observed by using biamperometry. This method has been used fo r determination of NCl3 concentration in synthetic samples.