Spatially Selective Diffusion-Ordered NMR Spectroscopy for High-Resolution Mixture Analysis in Inhomogeneous Magnetic Fields

Diffusion-ordered NMR spectroscopy (DOSY) serves as a robust spectroscopic method for the analysis of intact mixtures by resolving the individual components and their diffusion properties. However, the ability of DOSY generally relies on spectral resolution of the acquired 1D diffusion-weighted NMR spectra, thus encountering the challenges of diffusion measurements under adverse magnetic field conditions. Herein, a spatially selective-based DOSY approach that is able to overcome the influences of magnetic field inhomogeneity is reported for high-resolution mixture analysis in inhomogeneous magnetic fields. By integrating spatially selective excitation with internal diffusion encoding, this approach delivers high-resolution diffusion-dependent spectra along the chemical shift dimension and enhances the DOSY performance to distinguish diffusion behaviors along the diffusion dimension, even under adverse magnetic field conditions. Moreover, this approach demonstrates its applicability for monitoring electrochemical reactions through <i>in situ</i> electrochemical NMR. Therefore, this advancement extends the applicability of DOSY techniques and offers new opportunities for studies on complex chemical and biological mixtures.