COLORIMETRIC DETERMINATION OF CHLORINE DIOXIDE WITH M-AMINOBENZYL ALCOHOL

We propose a simple colorimetric method for determining chlorine dioxi de in water in the presence of hypochlorite and/or chlorite. This meth od is based on the coloration of an m-aminobenzyl alcohol (ABA). The r eagent solution changes from colorless to red-violet in the presence o f chlorine dioxide. Since the red-violet coloration is proportional to the concentration of chlorine dioxide, this concentration can be dete rmined by comparing it to a color standard of chloranilic acid. When A BA and chlorine dioxide react for 10 min at pH 2-7, the detection limi t of the chlorine dioxide is 0.1 ppm. The maximum absorption wavelengt h of the reaction product of ABA and chlorine dioxide is 532 nm. This product was separated by column chromatography, and the structure (C7H 5O3Cl) was then determined by ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR), and mass (MS) analyses.