Analytical characterization of N-halogenated peptides produced by disinfection: Formation, degradation, and occurrence in water

Abstract

Organic N -haloamines are water disinfection byproducts resulting from reactions between dissolved organic nitrogen and disinfectants . N -halogenated peptides, an important group of organic N -haloamines, have been overlooked over the past. In this review, we highlight peptides as the precursors for N -halogenated peptides during wastewater and drinking water disinfection. We discuss the analysis of N -halogenated peptides using methods based on titration , spectrophotometry , chromatography , and advanced liquid chromatography–mass spectrometry and the studies of the formation, degradation, and occurrence of N -halogenated peptides in water. While each method contributes to the evaluation of mechanisms and kinetics of formation and degradation of N -halogenated peptides in laboratory solution, only the development of highly sensitive and selective mass spectrometric methods enables the detection of trace levels of N -halogenated peptides in authentic disinfected water samples. Overall, reactions between peptides and disinfectants take place in milliseconds through an electrophilic substitution process. The N -halogenated peptides formed are relatively stable, leading to their sustainability in disinfected water. The recent detection of N -chlorinated peptides as disinfection byproducts using liquid chromatography–mass spectrometry in drinking water brings attention to these compounds. Further investigation of N -halogenated peptides on their occurrence and toxicological impacts are required to evaluate their health relevance.