Abstract
Nitrogenous substances produced by the ozonization of azo dyes [ 1 ]-[ 5 ] in aqueous solution were investigated. Nitrogen gas was found to be the main product. The yields of nitrogen gas, differing from one another due to the variety of dyes, were 65-92% based on the total nitrogen of azo group and pyrazole ring. Only minor amount of nitrate was produced. In the case of [ 2 ] in addition to nitrate, a small amount of ammonium ion was produced. The qualitative analyses of nitrogenous residue after the ozonization by means of spot tests showed the absence of nitrosamine, C-nitroso, nitro, and amine compounds.
