Ultra-selective 2D NMR DOSY with preserved J-coupling

Diffusion-ordered spectroscopy (DOSY) is a powerful nuclear magnetic resonance (NMR) technique for analyzing the components of complex mixtures. However, severe signal overlap in ¹H NMR often complicates accurate diffusion coefficient measurements and component identification. This problem is particularly pronounced in multicomponent mixtures containing structurally related compounds.

We have developed an ultra-selective DOSY method termed US-DOSY, which combines the GEMSTONE ultra-selective module with the conventional BPPSTE-LED DOSY method. By selectively isolating individual J-coupled multiplets from overlapped regions, US-DOSY enables more accurate diffusion measurements while retaining the scalar-coupling patterns useful for structural verification. The effectiveness of US-DOSY is demonstrated through the analysis of three mixtures, including a concentrated eight-component Fischer-Tropsch wastewater model mixture. US-DOSY enables more reliable resonance assignment and component-specific diffusion analysis.

This method serves as a valuable complement to existing NMR techniques and provides a useful targeted NMR tool for high-resolution analysis of complex mixtures.