AZO DYE AQUEOUS SOLUTION, PREPARATION METHOD AND USE

摘要

The invention concerns a stable aqueous solution (A) comprising an azo dye, whereof the colouring action or the intensity of the colouring action is modified in the presence of chlorine dioxide, a borate buffer solution and one or several masking agent(s). The invention also concerns a method for preparing said solution and its use for determining residual chlorine dioxide in water.