An approach to fast 2D nuclear magnetic resonance at low concentration based on p-H2-induced polarization and nonuniform sampling

Abstract

Recent developments in para-hydrogen-induced polarization (PHIP) methods allow the nuclear magnetic resonance (NMR) detection of specific classes of compounds, down to sub-micromolar concentration in solution. However, when dealing with complex mixtures, signal resolution requires the acquisition of 2D PHIP-NMR spectra, which often results in long experimental times. This strongly limits the applicability of these 2D PHIP-NMR techniques in areas in which high-throughput analysis is required. Here, we present a combination of fast acquisition and nonuniform sampling that can afford a 10-fold reduction in measuring time without compromising the spectral quality. This approach was tested on a mixture of substrates at micromolar concentration, for which a resolved 2D PHIP spectrum was acquired in less than 3 min.