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.
Rotzinger et al. (Tue,) studied this question.