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Insensitive nuclei enhancement by polarization transfer (INEPT) is a signal enhancement method used in NMR spectroscopy.It involves the transfer of nuclear spin polarization from spins with large Boltzmann population differences to nuclear spins of interest with lower Boltzmann population differences. [1]
Graphical representation of the INEPT NMR pulse sequence. INEPT is utilized often to improve 15 N resolution because it can accommodate negative gyromagnetic ratios, increases Boltzmann polarization, and decreases T 1 relaxation. [3] Insensitive nuclei enhanced by polarization transfer (INEPT) is a signal
The HSQC experiment is a highly sensitive 2D-NMR experiment and was first described in a 1 H— 15 N system, but is also applicable to other nuclei such as 1 H— 13 C and 1 H— 31 P. The basic scheme of this experiment involves the transfer of magnetization on the proton to the second nucleus, which may be 15 N, 13 C or 31 P, via an INEPT ...
The linewidth is optimized for polarization transfer from electrons to nuclei, when it is close to the nuclear Larmor frequency. The optimization is related to an embedded three-spin (electron-electron-nucleus) process that mutually flips the coupled three spins under the energy conservation (mainly) of the Zeeman interactions.
A phenomenological definition of the NOE in nuclear magnetic resonance spectroscopy (NMR) is the change in the integrated intensity (positive or negative) of one NMR resonance that occurs when another is saturated by irradiation with an RF field. The change in resonance intensity of a nucleus is a consequence of the nucleus being close in space ...
Considering these techniques from the opposite perspective, that magnetization (i.e. spin polarization) is being transferred from the bulk water to the spin-saturated hydration population, allows one to conceptually unify chemical exchange methods with other techniques that transfer magnetization between nuclei populations.
Hyperpolarization is the spin polarization of the atomic nuclei of a material in a magnetic field far beyond thermal equilibrium conditions determined by the Boltzmann distribution. [1] It can be applied to gases such as 129 Xe and 3 He , and small molecules where the polarization levels can be enhanced by a factor of 10 4 –10 5 above thermal ...
In magnetic resonance imaging (MRI) and nuclear magnetic resonance spectroscopy (NMR), an observable nuclear spin polarization (magnetization) is created by a homogeneous magnetic field. This field makes the magnetic dipole moments of the sample precess at the resonance frequency of the nuclei. At thermal equilibrium, nuclear spins precess ...