Frozen water NMR lineshape analysis enables absolute polarization quantification
File(s)
Accepted version
OA Location
Author(s)
Koptyug, Igor
Stern, Quentin
Jannin, Sami
Elliott, Stuart J
Type
Journal Article
Abstract
Typical magnetic resonance experiments are routinely limited by weak signal responses. In some cases, the low intrinsic sensitivity can be alleviated by the implementation of hyperpolarization technologies. Dissolution-dynamic nuclear polarization offers a means of hyperpolarizing small molecules. Hyperpolarized water is employed in several dynamic nuclear polarization studies, and hence accurate and rapid quantification of the 1H polarization level is of utmost importance. The solid-state nuclear magnetic resonance spectrum of water acquired under dissolution-dynamic nuclear polarization conditions has revealed lineshapes which become asymmetric at high levels of 1H polarization, which is an interesting fundamental problem in itself, but also complicates data interpretation and can prevent correct estimations of polarization levels achieved. In previous studies, attempts to simulate the 1H spectral lineshape of water as a function of the 1H polarization led to significant disagreement with the experimental results. Here we propose and demonstrate that such simulations, and therefore polarization quantification, can be implemented accurately, in particular by taking into account the detector dead time during 1H signal acquisition that can lead to severe spectral distortions. Based on these findings, we employed an echo-based radiofrequency pulse sequence to achieve distortion-free 1H spectra of hyperpolarized water, and adequate simulations of these echo-based spectra were implemented to extract the absolute 1H polarization level from the hyperpolarized water signal only, thus alleviating the need for lengthy and insensitive measurements of thermal equilibrium signals.
Date Issued
2022-03-14
Date Acceptance
2022-02-09
Citation
Physical Chemistry Chemical Physics, 2022, 24 (10), pp.5956-5964
ISSN
1463-9076
Publisher
Royal Society of Chemistry
Start Page
5956
End Page
5964
Journal / Book Title
Physical Chemistry Chemical Physics
Volume
24
Issue
10
Copyright Statement
© 2022 Royal Society of Chemistry.
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/35195621
Subjects
Chemistry
Chemistry, Physical
CROSS-POLARIZATION
DYNAMIC NUCLEAR-POLARIZATION
EXCITATION
HYPERPOLARIZED WATER
PARA-HYDROGEN
Physical Sciences
Physics
Physics, Atomic, Molecular & Chemical
RELAXATION
Science & Technology
SOLID-STATE NMR
SPECTROSCOPY
SPIN
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2022-02-15