Disinfection byproduct research has focused on low molecular weight, predominantly volatile byproducts, such as trihalomethanes and haloacetic acids, that accumulate as the end products of a long series of reactions.  Research with model precursors demonstrates that these final products typically form at &lt;1% yield, reflecting the difficulty associated with cleaving carbon-carbon bonds to liberate 1- or 2-carbon final products from larger structures.  While amino acids have served as model precursors for many structures, only ~6 of the 20 common amino acids are very reactive with chlorine.  This study characterizes the initial products formed from chlorine reactions with tryptophan and histidine.  Yields of these initial products, which retained the essential backbone structure of the amino acids, were high, accounting for &gt;50% molar transformation of the parent compounds.  These intermediates eventually degraded to low molecular weight products at lower yields.  While trihalomethanes are often used to characterize exposure to DBPs in drinking water distribution systems, our results indicate that trihalomethanes do not correlate with overall DBP exposure, because they do not capture exposure to these intermediate products.

Chlorine transformation products of tryptophan and histidine: Intermediate vs. final products

ACS Fall 2020 Virtual Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.