Zero-Quantum filtered Perfect NOESY: Enhanced sensitivity for NOE cross peaks perturbed by Zero Quantum artefacts

TL;DR

This paper introduces a zero-quantum filtered perfect NOESY technique that enhances sensitivity by suppressing zero quantum artefacts, enabling better detection of NOE cross peaks in NMR spectroscopy.

Contribution

It presents a novel method combining partial perfect echo decoupling with zero quantum filtering to improve NOESY sensitivity for extended t1 periods.

Findings

Enhanced NOE cross peak sensitivity in NMR spectra.

Suppression of zero quantum artefacts with partial decoupling.

Effective elimination of residual ZQ coherence using ZQ filter.

Abstract

Evolution of homonuclear J-coupling during t1 period creates Zero Quantum artefacts which seriously degrade the performance of 2D NOESY. In our previous work [28], it is demonstrated that creation of such artefacts can be prevented by incorporation of a perfect echo based broadband homo-nuclear decoupling technique during t1 period that also allows chemical shift encoding. However, such experiments have limited F1 resolution as the perfect echo based decoupling remains efficient for interpulse delay 2{\tau} (=t1) short compared to 1/J. A solution to this problem is provided in the present work where we show that even a partial decoupling effect of a perfect echo block for extended t1 period close to 1/2J greatly suppress the build up of antiphase content and thereby enhances the sensitivity of corresponding NOE cross peaks. The partial decoupling do lead to generation of partial ZQ coherence which is further eliminated by application of a ZQ filter.