Maximizing spectral sensitivity without compromising resolution in phase-incremented, steady-state solution NMR.

NMR acquisitions based on Ernst-angle excitations are widely used for maximizing spectral sensitivity without compromising bandwidth or resolution. However, if relaxation times T, T are long and similar, as is often the case in liquids, steady-state free-precession (SSFP) experiments could provide higher sensitivity per (SNR). Although strong offset dependencies and poor spectral resolutions have impeded SSFP's analytical applications, this study reexplores if, when and how can phase-incremented (PI) SSFP schemes overcome these drawbacks. It is found that PI-SSFP can indeed provide a superior SNR than Ernst-angle FT-NMR acquisitions, but that achieving this requires using relatively large flip angles. This, however, can restrict PI-SSFP's spectral resolution and lead to distorted line shapes; to deal with this we introduce here a new SSFP outlook that overcomes this dichotomy. This outlook also leads to a new processing pipeline for PI-SSFP acquisitions, providing high spectral resolution even when utilizing relatively the large flip angles. The enhanced SNR that the ensuing method can provide over FT-based NMR counterparts, is demonstrated with a series of C and N investigations on organic compounds.