Variable spacing Fast-T 1ρ for the analysis of fast relaxing species at low-field
Year: 2025
Type: article
Abstract: T 1ρ is a powerful analytical technique capable of probing motions on the timescale of molecular dynamics. Conventional T 1ρ approaches are performed on high-field NMR magnets (typically > 2 T) and rely on step-by-step data acquisition, resulting in relatively long experiments and acquisitions that are affected by non-negligible internal gradient effects and strict Specific Absorption Rate limits. The work presented herein reports the development of novel one- and two-dimensional Fast- T 1ρ pulse sequences on a 2 MHz benchtop NMR spectrometer. The developed method enables the observation of fast-relaxing species down to the millisecond timescale through application of a variably-spaced spin-lock duration array with delay spacings as short as 100 μ s. Fast- T 1ρ and Fast- T 1 - T 1 ρ pulse sequences have been developed which show significantly faster acquisition relative to conventional T 1ρ , illustrated with a 6-fold and 25-fold reduction in experiment time respectively. Theses techniques were demonstrated to be robust and accurate with measured T 1ρ values for bulk glycerol showing a maximum difference of 5.4% between Fast- T 1ρ and conventional T 1ρ experiments. The power of this method is exemplified through the simultaneous observation of multiple relaxation environments within a porous γ -Al 2 O 3 sample imbibed with an ethanol:water mixture, where T 1ρ relaxation rates of two orders of magnitude difference (2.4 ms to 370 ms) were captured.
Source: Journal of Magnetic Resonance
Institutions: University of Cambridge, Shell (United States)
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,500
OpenAlex ID: W4416843748