One-Step Dual-Functionalized Poly(fluorinated-aniline) for Broad-Spectrum and Highly Efficient Extraction of Per- and Polyfluoroalkyl Substances

Rapid, sensitive and high-throughput analysis of Per- and polyfluoroalkyl substances (PFASs) in aquatic environments is of significance for safeguarding environmental and human health. However, efficient broad-spectrum extraction of PFASs from complex media remains challenging due to the diversity in their structural and physicochemical properties. Herein, a novel poly(fluorinated-aniline) nanofiber membrane (PFANI NFM) was successfully synthesized via a facile one-step in situ oxidative polymerization method. Owing to its unique structure and the multifunctional groups, PFANI NFM exhibits consistently high extraction efficiency (>99.5%) for all studied PFASs with diverse chain lengths (C4-C14). Merely 4 mg of PFANI NFM enables efficient extraction of 14 PFASs from 10 mL water samples; elution with 1 mL of 1% ammonia/acetonitrile allows direct subsequent high-performance liquid chromatography-tandem mass spectrometry analysis. Moreover, the excellent reusability made PFANI NFM valuable in practical application. The established method displays low limits of detection (LODs) of 0.63-5.61 ng L⁻¹, a wide linearity of 2.11-100,000 ng L⁻¹ with correlation coefficient (R²) ≥ 0.9905, and satisfactory recoveries (90.25-119.23%) and precision (RSDs ≤ 9.95%). Practical application in real water samples (e.g., wastewater, surface water) confirms its feasibility for PFASs monitoring. Additionally, various characterization techniques and density functional theory calculations reveal that electrostatic attraction, F-F interactions, F-π stacking, hydrogen bonding, and ion exchange synergistically contribute to the adsorption of PFASs on PFANI NFM. This work highlights the potential of rationally designed NFMs with tailored structures and functionalities for the broad-spectrum enrichment and ultrasensitive determination of PFASs in practical applications.