NMR methods for characterizing molecular species in two immiscible solvents: application to SABRE-hyperpolarised species

Abstract

The potential of ¹H NMR for detecting solutes on either side of an interface between two immiscible liquids and studying their kinematic behavior is analysed. First, localised spectroscopy was used to monitor the migration of a solute from an aqueous phase to an organic phase and its self-diffusion coefficient was measured slice by slice within the two phases, validating the NMR approach. Next, a fast version of localised spectroscopy (Radsl-CSI) was designed and applied to track the migration of species hyperpolarised by parahydrogen from the organic phase where they are produced to the aqueous phase. This sequence evidenced the transfer of hyperpolarised pyridine from the organic phase to the aqueous phase.