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

TL;DR

This paper introduces a new NMR method to improve the clarity and signal strength of fluorine spectra in PFAS compounds.

Contribution

The novel approach uses band-selective homonuclear decoupling to enhance both resolution and intensity in 19F NMR spectra of PFAS.

Findings

PFAS mixtures with overlapping signals are resolved into individual singlets.

The method enables accurate identification and quantification of perfluorinated compounds.

Signal intensities are significantly enhanced without relying on chemical properties.

Abstract

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.

Figures