SABRE enhanced real time pure shift NMR spectroscopy

Pure shift NMR methods suppress the effect of homonuclear scalar couplings to produce NMR spectra consisting solely of a single signal for each chemically distinct site. They are increasingly relied upon for analysis of complex molecules and mixtures as they overcome the extensive signal overlap that complicates proton NMR spectra of all but the simplest species. Current broadband pure shift methodologies for 1D proton spectra suffer from reduced sensitivity compared to their conventional counterparts and typically require a large amount of instrument time for low concentration samples. In this study we demonstrate how the sensitivity limitation may be overcome by transiently increasing the bulk polarization using SABRE hyperpolarization. We utilize para-enriched dihydrogen to enhance the pure shift NMR resonances of pyridine by up to a factor of 60 in a single scan experiment and extend this to propose a method to unambiguously determine mixture components based on the enhancement of their pure shift NMR signals.