Metal-Organic Frameworks for the Trace Multiplexed Adsorption and Quantitation of 50 Per- and Polyfluoroalkyl Substances

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that pose significant health risks. With recent regulatory guidelines lowering safe drinking water advisory limits to parts-per-quadrillion (ppq) levels, the need for methods capable of detecting and quantifying many PFAS simultaneously in trace amounts has become increasingly critical. In this study, six metal-organic frameworks were evaluated as solid-phase extraction sorbents for multiplexed adsorption of PFAS, followed by quantitative liquid chromatography-tandem mass spectrometry. UiO-66 demonstrated the highest performance with 87% adsorption efficiency and 85% recovery for 33 PFAS spiked at 2 parts per billion. In multiplexed adsorption for 50 PFAS at concentrations of 200 ppq, UiO-66 achieved an average recovery of 75%, with detection limits as low as 4 ppq and an average detection limit of 108 ppq. Validation using six environmental water samples revealed quantifiable PFAS in all samples with 25 PFAS detected. Compared to polymeric resins, which typically detect PFAS in the 1–80 parts per trillion range, UiO-66 demonstrated enhanced sensitivity for multiplexed adsorption, capable of detecting concentrations in the low ppq range. These findings highlight the potential of UiO-66 for large-scale PFAS monitoring under increasingly stringent environmental regulations.