Evaluation of electrode methods for determining total residual chlorine in various water matrices

Abstract

Abstract Five electrode systems and procedures that are widely marketed for routine determination of total residual chlorine have been evaluated in a variety of water matrices. The performance, in terms of accuracy, precision, and sensitivity, has been determined for the Orion 97–70 Residual Chlorine Electrode, Chlortect Monitor, Lazar 136A Chlorine Electrode, the forward amperometric titration method, and the back amperometric titration method. Response times for the former too systems were comparable and ranged from 20–100 seconds for chlorine concentrations ranging from 0.3–7 ppm in all water matrices. The Lazar electrode had considerably longer response times. The Chlortect Monitor and the forward amperometric titration method gave the highest sensitivity, with values of + 0.005 and .01 ppm, respectively, at the 1 ppm level. However, the Lazar Electrode could not be completely evaluated because of inconsistencies in the marketed procedures. Each system and method gave a higher precision in chlorine de...