NMR Spin-Lock Induced Crossing (SLIC) dispersion and long-lived spin states of gaseous propane at low magnetic field (0.05T)

• Published in: Journal of magnetic resonance (1997) Vol. 276; pp. 78 - 85
• Main Authors: Barskiy, Danila A., Salnikov, Oleg G., Romanov, Alexey S., Feldman, Matthew A., Coffey, Aaron M., Kovtunov, Kirill V., Koptyug, Igor V., Chekmenev, Eduard Y.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2017
• Subjects: Computer Simulation; Contrast Media; Electromagnetic Fields; Gases - chemistry; Hyperpolarization; Long-lived spin states; Low field; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy - methods; MRI; NMR; Parahydrogen; Pressure; Propane; Propane - chemistry; Protons; Signal Processing, Computer-Assisted; Xenon Isotopes; NMR; MRI; Parahydrogen; Long-lived spin states; Low field; Hyperpolarization; Propane
• ISSN: 1090-7807; 1096-0856
• DOI: 10.1016/j.jmr.2017.01.014

[Display omitted] •Parahydrogen-induced polarization (PHIP) is used to produce hyperpolarized propane.•Long-lived spin states (LLSS) of propane are studied in low magnetic field (0.05T).•Spin-Lock Induced Crossing (SLIC) technique converts these LLSS into magnetization.•The NMR signal exhibits a well-resolved dispersion on B1 amplitude (SLIC dispersion). When parahydrogen reacts with propylene in low magnetic fields (e.g., 0.05T), the reaction product propane develops an overpopulation of pseudo-singlet nuclear spin states. We studied how the Spin-Lock Induced Crossing (SLIC) technique can be used to convert these pseudo-singlet spin states of hyperpolarized gaseous propane into observable magnetization and to detect 1H NMR signal directly at 0.05T. The theoretical simulation and experimental study of the NMR signal dependence on B1 power (SLIC amplitude) exhibits a well-resolved dispersion, which is induced by the spin-spin couplings in the eight-proton spin system of propane. We also measured the exponential decay time constants (TLLSS or TS) of these pseudo-singlet long-lived spin states (LLSS) by varying the time between hyperpolarized propane production and SLIC detection. We have found that, on average, TS is approximately 3 times longer than the corresponding T1 value under the same conditions in the range of pressures studied (up to 7.6atm). Moreover, TS may exceed 13s at pressures above 7atm in the gas phase. These results are in agreement with the previous reports, and they corroborate a great potential of long-lived hyperpolarized propane as an inhalable gaseous contrast agent for lung imaging and as a molecular tracer to study porous media using low-field NMR and MRI.