Chlorotyrosines and Oleic Acid Chlorohydrins as Byproducts in Disinfected Conventional Drinking Waters and Potable Reuse Waters

Abstract

Recent research indicates that the poorly characterized high-molecular weight disinfection byproduct (DBP) fraction (more than two carbons) contributes more to cytotoxicity than the one- to two-carbon DBPs of current interest. Peptides and lipids contribute to DBP precursors in water supplies. Although partially degraded, a portion of their monomers retain their structures. Using tyrosine and oleic acid as exemplars, this study illustrates the targeted analysis of their chlorinated byproducts as an approach to characterizing high-molecular weight DBPs. After biopolymers had been digested to liberate monomers, oleic acid was detected in four of six secondary effluents from potable reuse facilities at concentrations of up to 91 nM (47 μg/L), while its chlorohydrins were detected in two effluents at concentrations of up to 1.3 nM (0.43 μg/L). Tyrosine was detected in all six effluent samples at concentrations of up to 42 nM (7.6 μg/L). 3-Chlorotyrosine was detected in four samples at concentrations of up to 3.3 nM (0.71 μg/L), and 3,5-dichlorotyrosine was detected in three samples at concentrations of up to 2.1 nM (0.53 μg/L). These DBPs were detected in conventional drinking waters, but at lower frequencies and concentrations. When detected, the contribution of chlorohydrins to cytotoxicity was comparable to some, but not all, of the one- to two-carbon DBP classes.

Water Analysis: Emerging Contaminants and Current Issues

“…Chlorotyrosines and oleic acid chlorohydrins were found in another study by Suh et al at higher levels and higher frequency in potable reuse waters vs conventional drinking water. 91 This study used acid digestion to differentiate DBP formation from peptide-or lipid-bound typrosine and oleic acid precursors, respectively, and a target analysis of chlorinated in chloraminated potable reuse water. Chlorotyrosine and 3,5-dichlorotyrosine were detected, up to 0.71 and 0.53 μg/L, respectively, and chlorohydrins were found up to 0.43 μg/L.…”