AWWA JAW26408
Journal AWWA - Specificity of the DPD and Amperometric Titration Methods for Free Available Chlorine: A Review
Journal Article by American Water Works Association, 12/01/1989
Jensen, James N.;Johnson, J. Donald
Full Description
Both the DPD (N,N-diethyl-p-phenylenediamine) and amperometric titration methods for measuring free available chlorine (FAC) are subject to interference from monochloramine and organic chloramines. The measured FAC concentration in the presence of chloramines is often significantly larger than the true FAC residual. Interference in the DPD method can be reduced by rapid titrations. Interference in the amperometric titration method can be minimized by maintaining a 200-mV positive potential on the platinum electrode. Includes 70 references, tables, figure.