Revisiting Disinfection Byproducts with Supercritical Fluid Chromatography-High Resolution-Mass Spectrometry: Identification of Novel Halogenated Sulfonic Acids in Disinfected Drinking Water

Abstract

High resolution mass spectrometry (HRMS) coupled to either gas chromatography or reversed-phase liquid chromatography is the generic method to identify unknown disinfection byproducts (DBPs) but can easily overlook their highly polar fractions. In this study, we applied an alternative chromatographic separation method, supercritical fluid chromatography-HRMS, to characterize DBPs in disinfected water. In total, 15 DBPs were tentatively identified for the first time as haloacetonitrilesulfonic acids, haloacetamidesulfonic acids, and haloacetaldehydesulfonic acids. Cysteine, glutathione, and p-phenolsulfonic acid were found as precursors during lab-scale chlorination, with cysteine providing the highest yield. A mixture of the labeled analogues of these DBPs was prepared by chlorination of 13C3-15N-cysteine and analyzed using nuclear magnetic resonance spectroscopy for structural confirmation and quantification. A total of 6 drinking water treatment plants utilizing various source waters and treatment trains produced sulfonated DBPs upon disinfection. Those were widespread in the tap water of 8 cities across Europe, with estimated concentrations up to 50 and 800 ng/L for total haloacetonitrilesulfonic acids and haloacetaldehydesulfonic acids, respectively. Up to 850 ng/L haloacetonitrilesulfonic acids were found in 3 public swimming pools. Considering the stronger toxicity of haloacetonitriles, haloacetamides, and haloacetaldehydes than the regulated DBPs, these newly found sulfonic acid derivatives may also pose a health risk.

Emerging contaminants: A One Health perspective

“…For example, a recent study combined supercritical fluid chromatography (SFC) with HRMS to identify unknown disinfection by-products in drinking water. 134 Hydrophilic interaction chromatography (HILIC) is also commonly employed in orthogonal analysis to analyze polar compounds. For example, HILIC-HRMS was applied in disinfected water analysis, leading to the identification of a new class of polar disinfection by-products (DBPs)—halomethanesulfonic acids.…”

Should Transformation Products Change the Way We Manage Chemicals?

“…The commonly more mobile TPs are less removed than their precursors in subsequent treatment by activated carbon and can in some cases also be more toxic than the parent compound. − Although this issue is widely known, the variety of potential TPs following oxidative treatment is poorly understood and remains underexplored . The same is true for byproducts of drinking water disinfection. , In research on advanced oxidation processes there is a trend toward more selective oxidants (e.g., 1 O 2 or ferryl) with minimized scavenging by matrix components, such as dissolved organic matter (DOM), which may reduce full mineralization further, thus exacerbating TP formation. Biological post-treatment is frequently applied after disinfection or oxidation processes, as it was shown to efficiently remove some of the disinfection byproducts formed from DOM.…”

Predicting Transformation Products during Aqueous Oxidation Processes: Current State and Outlook

“…1,2,56,85−92 Very polar transformation products were also identified using IC-MS or SFC-MS/MS. 93,94 Experiments without quenching for dosed chemicals or in situ formed radicals followed by direct injection of samples to a MS/MS system may help to determine transient transformation products. 95 Some transient radicals can be identified by EPR techniques, although the available spin Figure 2.…”

“…Determination of transformation products using advanced analytical equipment such as LC-MS/MS, GC-MS/MS, or NMR helped to elucidate major reaction mechanisms based on stable end products. ,,,− Very polar transformation products were also identified using IC-MS or SFC-MS/MS. , Experiments without quenching for dosed chemicals or in situ formed radicals followed by direct injection of samples to a MS/MS system may help to determine transient transformation products . Some transient radicals can be identified by EPR techniques, although the available spin trapping agents are limited to nonhalogen or -nitrogen radicals.…”