The 2D-J-DOSY Experiment: Resolving Diffusion Coefficients in Mixtures

Many diffusion-ordered spectroscopy (DOSY) NMR techniques have recently been developed to aid in the deconvolution of complex mixtures. Spectroscopic separation based on chemical and physical properties facilitates the identification of mixture components while eliminating time-consuming separation steps and preserving the chemical environment. One way to improve resolution in such experiments is to spread the spectroscopic information into two dimensions. The 2D-J-DOSY experiment has been designed to resolve mixture components in terms of a chemical shift and proton coupling constant as well as distinguishing them on the basis of translational diffusion. Acquiring a series of spectra as a function of gradient amplitude permits the determination of diffusion coefficients for components that cannot be resolved in the one-dimensional (1D) 1H NMR spectrum. Comparison of the resulting values with those obtained through the traditional 1D diffusion experiment for a mixture of sugars validates The 2D-J-DOSY technique.