DOSY, is a technique for separating NMR signals by their diffusion coefficients.

Diffusion-ordered spectroscopy is a powerful NMR technique with a wide range of applications. It can be used to study how a molecule of interest diffuses in solution if two molecules are interacting with each other, or to resolve the peaks in a messy spectrum. We recently applied DOSY to a project where the final compound was difficult to purify. Significant amounts of leftover solvent and a contaminant made interpretation of the more traditional spectra difficult. Using DOSY, we were able to easily identify which signals belonged to the final product, complete the assignments, and verify that the reaction was a success. If you’re interested in learning more about DOSY or in using it, please contact the Duke NMR Center team today!

REF: https://www.spectroscopyeurope.com/article/dosy-nmr-new-tool-fake-drug-analyses