Variable spacing Fast-T <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si44.svg" display="inline" id="d1e388"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mi mathvariant="normal">1ρ</mml:mi> </mml:mrow> </mml:msub> </mml:math> for the an
T<sub>1ρ</sub> is a powerful analytical technique capable of probing motions on the timescale of molecular dynamics. Conventional T<sub>1ρ</sub> 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<sub>1ρ</sub> 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 μs. Fast-T<sub>1ρ</sub> and Fast-T<sub>1</sub>-T<sub>1ρ</sub> pulse sequences have been developed which show significantly faster acquisition relative to conventional T<sub>1ρ</sub>, illustrated with a 6-fold and 25-fold reduction in experiment time respectively. These techniques were demonstrated to be robust and accurate with measured T<sub>1ρ</sub> values for bulk glycerol showing a maximum difference of 5.4% between Fast-T<sub>1ρ</sub> and conventional T<sub>1ρ</sub> experiments. The power of this method is exemplified through the simultaneous observation of multiple relaxation environments within a porous γ-Al<sub>2</sub>O<sub>3</sub> sample imbibed with an ethanol:water mixture, where T<sub>1ρ</sub> relaxation rates of two orders of magnitude difference (2.4 ms to 370 ms) were captured.
Authors
- Matthias Appel (ORCID: https://orcid.org/0000-0002-7603-6734)
- Andrew J. Sederman (ORCID: https://orcid.org/0000-0002-7866-5550)
- Lynn F. Gladden (ORCID: https://orcid.org/0000-0001-9519-0406)
- Alastair D. Robinson (ORCID: https://orcid.org/0000-0002-1173-032X)
- Jordan Ward-Williams (ORCID: https://orcid.org/0000-0001-8969-1239)
- Mick D. Mantle
Institutions
- University of Cambridge (GB)
- Shell (United States) (US)
Publication Details
- Journal
- Journal of Magnetic Resonance
- Published
- 2025-12-01
- DOI
- https://doi.org/10.1016/j.jmr.2025.108002
- Primary Topic
- NMR spectroscopy and applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00