Multi-sorbent passive sampler for the preconcentration of contaminants with broad polarity spectrum in drinking...

The occurrence of Persistent and Mobile Organic Contaminants (PMOCs), especially very polar compounds (log P <1), remains poorly characterized in drinking water due to analytical limitations. These compounds are highly soluble, weakly retained on conventional C₁₈ materials, and may persist through treatment processes, raising concerns about potential health and environmental impacts. To address this challenge, we developed a passive sampler combining three complementary sorbents (HLB, SAX, and SCX) to enhance retention across a wide polarity range. The device was evaluated under controlled conditions (47 target substances, 3 concentrations, triplicates) to assess sorption performance and pH sensitivity. Results confirmed the complementarity of the sorbents with broad retention for HLB and more specific patterns for SAX and SCX. The tool was then deployed for 15 days in both raw and treated waters across seven drinking water treatment plants. A total of 37 contaminants were detected, including 20 with log P < 1. The treatment processes proved effective, with an average 13-fold reduction in the accumulated quantities between RW and TW, although the contamination profile in TW appeared more complex, likely reflecting presence of transformation products and residual highly polar compounds. Compounds with log P < 1 were found to pass more efficiently through drinking water treatment processes, consistent with their higher polarity and lower affinity for conventional removal pathways. By integrating exposure over time, the sampler lowered detection limits and offered a more exhaustive contamination profile. This approach supports improved PMOC surveillance and lays the groundwork for future quantitative or untargeted monitoring strategies in drinking water systems.