Identification of LC-HRMS nontarget signals in groundwater after source related prioritization

Groundwater is a major drinking water resource but its quality with regard to organic micropollutants (MPs) insufficiently assessed. Therefore, we aimed investigate Swiss groundwater more comprehensively using liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). First, samples from 60 sites were classified as having high or low urban agricultural influence based on 498 target compounds associated either sources. Second, all LC-HRMS signals related their potential origin (urban, and agricultural, not classifiable) occurrence intensity in the samples. A considerable fraction of estimated concentrations and/or sources could be explained by 139 detected targets. The most intense nontarget automatically annotated structure proposals MetFrag SIRIUS4/CSI:FingerID list >988,000 compounds. Additionally, suspect screening was performed for 1162 predicted mobility primarily Finally, 12 nontargets 11 suspects identified unequivocally (Level 1), while 17 further tentatively 2a/3). amongst these 13 pollutants thus far reported groundwater, such as: industrial chemicals 2,5-dichlorobenzenesulfonic acid (19 detections, up 100 ng L−1), phenylphosponic (10 50 triisopropanolamine borate (2 40 O-des[2-aminoethyl]-O-carboxymethyl dehydroamlodipine, transformation product (TP) blood pressure regulator amlodipine (17 detections), TP SYN542490 herbicide metolachlor 3, 33 100–500 L−1). One monitoring site contaminated than other total MPs, which supported elucidation site-specific carcinogen chlorendic acid, various naphthalenedisulfonic acids. Many remained unknown, overall, source prioritisation proved an effective approach support identification groundwater.