Persistent and Mobile Organic Contaminants: Quantification and Nontarget Analysis in Greater Boston Drinking and...

Persistent and mobile organic contaminants (PMOCs) evade water treatment technologies and current monitoring efforts, posing a threat to water resources. To investigate this largely unexplored chemical space, we developed an analytical workflow based on sample enrichment by evaporative concentration and chromatographic separation by zwitterion-HILIC to quantify known and discover previously unknown PMOCs in water samples. We applied this workflow to drinking and surface water samples in the Greater Boston area of Massachusetts, USA, in a pilot effort to address the geographical gap in PMOC analysis, as the vast majority of studies take place in European countries. We targeted 19 analytes for quantitation via isotope dilution. TFA was estimated at hundreds of ng/L in 6 municipal tap water samples, and 13 analytes were quantified at 10-100s ng/L in surface water samples. 191 total compounds were annotated via nontarget analysis in drinking water, including 12 level 1, 32 level 2, and 44 level 3 identifications, and we report 12 new level 2+ drinking water contaminants, including 1-methylguanidine, 1,2-dimethylguanidine, and trimethylarsine oxide. Suspect screening of surface water samples revealed 80 PMOC candidate compounds. We cross-referenced surface and drinking water data to find 50 common contaminants despite a lack of hydrological connection between sample sources, 12 of which occurred in tap, bottled, and surface water, including halogenated methanesulfonic acid disinfection byproducts and the newly reported 1,2-dimethylguanidine. Our results reinforce the need for tailored analytical methods and widespread geographic efforts to achieve a holistic understanding of PMOC contamination and its implications for aquatic and human health.