High-resolution NMR in inhomogeneous fields

A new NMR technique is presented that yields high-resolution, 1-D NMR spectra of solutes in inhomogeneous magnetic fields. The method exploits the nuclear Overhauser effect which couples the longitudinal relaxation of solvent and solute nuclear spins. Effectively, the solvent spins serve as reporters or local gaussmeters for the solute spins. Both 2-D and 1-D versions of this new experiment are reported. Potential applications of the method include in vivo NMR spectroscopy, where the field homogeneity is always degraded by the magnetic susceptibilities of the various tissues. (C) 1997 Elsevier Science B.V.