Disinfection efficacy of organic chloramines.

The disinfection efficacies of model organic chloramines were investigated. Twenty amino acids and two nucleic acid bases were chlorinated separately with sodium hypochlorite at a Cl:N molar ratio of 0.4:1, and were then used to treat an E. coli suspension for 60 min. DPD/FAS titration was carried out to obtain the concentration of the chlorinated nitrogenous organic compounds as a function of time. In addition, membrane introduction mass spectrometry (MIMS) was used to quantify inorganic chloramines (mono-, di-, and trichloramine). The results of these experiments showed that the organic chloramines examined in this research had little or no effect on the viability of E. coli. MIMS analyses demonstrated that there was no quantifiable formation of inorganic chloramines when the organic nitrogen compounds were chlorinated. Copyright 2002 Elsevier Science Ltd.