INVESTIGATION INTO THE DETECTION OF CHLORINE SPECIES BY RHODAMINE 6G CHEMILUMINESCENCE WITH ELECTROCHEMICAL MODIFICATION

A flow system for the determination of free chlorine by a chemiluminescence reaction with Rhodamine 6G in aqueous solution is described. The system was optimized such that a detection limit (signal-to-noise ratio = 3) of 90 mu g l(-1) was obtained for free chlorine. The system was found to detect bound available chlorine in water by electrochemiluminescence under the same conditions, but in the presence of a charged electrode. In principle, this system could be used to monitor both free chlorine and total available chlorine by switching the electrode voltage. The mechanism of the chemiluminescence is discussed with reference to the analytical advantages of linear calibrations.