TY - JOUR

T1 - NMR Spin-Lock Induced Crossing (SLIC) dispersion and long-lived spin states of gaseous propane at low magnetic field (0.05 T)

AU - Barskiy, Danila A.

AU - Salnikov, Oleg G.

AU - Romanov, Alexey S.

AU - Feldman, Matthew A.

AU - Coffey, Aaron M.

AU - Kovtunov, Kirill V.

AU - Koptyug, Igor V.

AU - Chekmenev, Eduard Y.

N1 - Copyright © 2017 Elsevier Inc. All rights reserved.

PY - 2017/3/1

Y1 - 2017/3/1

N2 - When parahydrogen reacts with propylene in low magnetic fields (e.g., 0.05 T), 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 0.05 T. 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 7.6 atm). Moreover, TS may exceed 13 s at pressures above 7 atm 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.

AB - When parahydrogen reacts with propylene in low magnetic fields (e.g., 0.05 T), 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 0.05 T. 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 7.6 atm). Moreover, TS may exceed 13 s at pressures above 7 atm 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.

KW - Hyperpolarization

KW - Long-lived spin states

KW - Low field

KW - MRI

KW - NMR

KW - Parahydrogen

KW - Propane

KW - PARA-HYDROGEN

KW - 4-SPIN SYSTEMS

KW - SINGLET-STATES

KW - NOISE RATIO

KW - N-15 HYPERPOLARIZATION

KW - DYNAMIC NUCLEAR-POLARIZATION

KW - RESONANCE

KW - PARAHYDROGEN-INDUCED POLARIZATION

KW - INERT FLUORINATED GASES

KW - IN-SITU

UR - http://www.scopus.com/inward/record.url?scp=85010876817&partnerID=8YFLogxK

U2 - 10.1016/j.jmr.2017.01.014

DO - 10.1016/j.jmr.2017.01.014

M3 - Article

C2 - 28152435

AN - SCOPUS:85010876817

VL - 276

SP - 78

EP - 85

JO - Journal of Magnetic Resonance

JF - Journal of Magnetic Resonance

SN - 1090-7807

ER -