Sorption properties of several polyethersulfone membranes for hydrophilic and hydrophobic emerging contaminants:...

The presence of emerging contaminants (ECs) in aqueous matrices has gained attention during the last decades due to their possible negative effects on the environment and on human health. In this context, passive sampling represents a promising strategy for the monitoring of ECs in water. Polyethersulfone (PES) membranes have been employed in passive samplers both as a sorptive material and as a protective layer. To understand the properties of PES in the sorption of ECs with different physico-chemical properties and develop a reliable sampling strategy, PES-water partition coefficients (K_PESw) can be evaluated. In the present work, K_PESw was investigated for 37 compounds using PES membranes with the same pore sizes (0.1 μm) but coming from different suppliers and a PES membrane with a larger pore size (0.45 μm). K_PESw values were compared based on pore dimensions and supplier, and different sorption trends were observed. Moreover, two different setups were employed to evaluate the partition coefficients using the most employed PES membranes in passive sampling applications. The logK_PESw values obtained, ranging from -0.1 ± 0.2 to 6.26 ± 0.03, were correlated with the analytes' physico-chemical properties using a multivariate approach, highlighting hydrophobicity as the main driving force in the uptake. Finally, the K_PESw values obtained in this work and in previous studies were correlated with the analyte's distribution coefficients, confirming the influence of the hydrophobic nature of the compounds on the sorption. These observations can guide the design of monitoring campaigns, providing hints on the proper material to use for sampling and on the selection of target compounds.