An Improved Accurate Method for The Automated Determination of Residual Chlorine in Saline Water

Abstract

The determination of residual chlorine with o-tolidine in saline water has been studied. The
method proposed is based on the use of reverse flow injection analysis for the monitoring of
chlorine in saline samples with low cost and reduction of waste production. The linearity of the
method (up to 1.8 mg L-1) covers the chlorine concentrations used in most water treatment
processes. The precision of the method was 0.93 % (RSD) for 1.4 mg L-1 chlorine. The method is
also applicable to non-saline water and the limits of detection were 0.11 mgL-1 and 0.04 mg L-1
for saline and non-saline matrices, respectively. The method has been successfully applied to the
analysis of residual chlorine in both synthetic and real samples. The sample throughput was
60 h-1.