Comprehensive HRMS-screening for persistent, mobile, and toxic compounds in first flush urban stormwater

Water scarcity drives water-stressed regions to make use of all available resources. Consequently, urban stormwater is gaining recognition as a valuable resource, for instance to replenish aquifers; thus, enhancing water supply. However, it carries contaminants that could limit its potential uses, highlighting those recently categorized as persistent, mobile, and toxic (PMT) compounds. In order to conduct broad screening for the presence of PMT compounds in stormwater first-flush samples and rainwater, two instruments based on Gas and Liquid Chromatography coupled to Quadrupole-Time-of-Flight Mass Spectrometry were used, and both suspect and target screening were performed. After prioritization 42 PMTs were detected, of which 24 PMTs were quantified. The results showed that 66% of the quantified PMTs were present in more than 50% of the samples, with average concentrations ranging from 2 ng L-1 to 2.78 µg L-1. Of the target PMTs, 11 were quantified for the first time in runoff samples.