Enhancing both the Intensities and Resolution of ¹⁹ F NMR Spectra of PFAS through Band-Selective Homonuclear Decoupling

A method for acquiring fluorine nuclear magnetic resonance (¹⁹F NMR) spectra of perfluoroalkyl and polyfluoroalkyl substances (PFASs) is described. The experiment uses band-selective homonuclear decoupling of the CF₃ spectral region (around -82.4 ppm) and results in spectra showing both enhanced resolution and enhanced signal intensities for perfluorinated compounds. PFAS mixtures, which show highly overlapped multiplet signals in conventional ¹⁹F NMR spectra, are reduced to individual separated singlets, enabling not only their identification but also quantification, which does not depend on the chemical nature of each compound.