Dual-functional metal-organic frameworks for adsorptive removal and ultra-trace quantitation of 50 per- and polyfluoroalkyl substances in water

Per- and polyfluoroalkyl substances (PFAS) are persistent and pervasive environmental contaminants associated with significant health risks. Recent regulatory shifts reducing safe drinking water advisory limits to parts-per-quadrillion (pg/L) levels underscore the urgent need for robust methodologies capable of detecting and removing PFAS at ultra-trace concentrations. In this study, six metal-organic frameworks (MOFs) were systematically evaluated for their dual functionality to preconcentrate PFAS for ultra-trace analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and as sorbents for adsorptive removal of PFAS from water at environmentally relevant concentrations (200 pg/L to 2 µg/L). UiO-66 enabled the quantification of 50 PFAS at spiked concentrations as low as 200 pg/L, with detection limits down to 17 pg/L. These results are comparable to, or better than conventional technical sorbents in LC-MS/MS workflows involving 50 PFAS, whilst using less sorbent (100 vs 250 mg) and volume (250 vs 1000 mL) per sample. In parallel, UiO-67 removed an average of 99% of all 50 PFAS (2 µg/L) from water within 30 min using 10 mg of material. Together, these findings demonstrate the viability of MOFs for both ultra-trace analysis and removal of diverse PFAS chemistries in environmental water matrices, offering a promising strategy for integrated environmental monitoring and treatment.