Polyethersulfone Membrane As a Single-Phase Passive Sampler: Evaluation of the Sampling Performance for Emerging Contaminants in Water

The use of polyethersulfone (PES) membranes as single-phase passive samplers was tested for the detection of nine emerging contaminants (three estrogens, bisphenol-A, triclosan and four UV-filters). The sorption and kinetics onto PES were assessed using tap water and synthetic seawater. To obtain a reliable sampling procedure, the accuracy of the extraction method was evaluated in terms of recovery, matrix effect and precision. The recoveries ranged between 66 % and 85 %, while matrix effects resulted acceptable (58 %-126 %), even in field conditions. The affinity of the target compounds for the sorbent was first evaluated by PES-water partition coefficients. Afterwards, several calibrations were performed to study the uptake kinetics, also considering the effect of the flow regime. A linear uptake during a 96-hour deployment was observed for UV-filters and triclosan, allowing the estimation of their sampling rates, which ranged between 0.036 and 0.066 and 0.05-0.10 L/d cm-2 in tap water and synthetic seawater, respectively. Instead, an apparent equilibrium was reached for the estrogens and bisphenol-A within 24 h. To better understand the sorption behavior, Principal Component Analysis was implemented by considering several physico-chemical parameters of the analytes. This approach permitted to identify three groups which reflect the different sorption mechanisms. Finally, a 4-day field exposure of PES was carried out in an Italian harbor along with the collection of spot samples, treated by classical SPE. Five out of the nine analytes were detected in the passive sampler, while only three by classical spot sampling. For the three UVfilters detected using passive sampling, it was possible to evaluate the time-weighted average concentrations, ranging between 0.13 and 9 ng/L. The good performances of this passive sampler make it promising for the shortterm monitoring of a range of contaminants in potentially impacted seawater, with enhanced sensitivity compared to classical spot sampling.