Through-Space Multinuclear Magnetic Resonance Signal Enhancement Induced by Parahydrogen and Radiofrequency Amplification by Stimulated Emission of Radiation.
Anal Chem
; 94(43): 15010-15017, 2022 11 01.
Article
em En
| MEDLINE
| ID: mdl-36264746
ABSTRACT
Hyperpolarized (i.e., polarized far beyond the thermal equilibrium) nuclear spins can result in the radiofrequency amplification by stimulated emission of radiation (RASER) effect. Here, we show the utility of RASER to amplify nuclear magnetic resonance (NMR) signals of solute and solvent molecules in the liquid state. Specifically, parahydrogen-induced RASER was used to spontaneously enhance nuclear spin polarization of protons and heteronuclei (here 19F and 31P) in a wide range of molecules. The magnitude of the effect correlates with the T1 relaxation time of the target nuclear spins. A series of control experiments validate the through-space dipolar mechanism of the RASER-assisted polarization transfer between the parahydrogen-polarized compound and to-be-hyperpolarized nuclei of the target molecule. Frequency-selective saturation of the RASER-active resonances was used to control the RASER and the amplitude of spontaneous polarization transfer. Spin dynamics simulations support our experimental RASER studies. The enhanced NMR sensitivity may benefit various NMR applications such as mixture analysis, metabolomics, and structure determination.
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Base de dados:
MEDLINE
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Ondas de Rádio
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Imageamento por Ressonância Magnética
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article