In deuterated molecules such as [1-C-13]pyruvate-d(3), the nuclear spin polarization of C-13 nuclei can be enhanced by combining Hartmann-Hahn cross-polarization (CP) at low temperatures (1.2 K) with dissolution dynamic nuclear polarization (D-DNP). The polarization is transferred from remote solvent protons to the C-13 spins of interest. This allows one not only to slightly reduce build-up times but also to increase polarization levels and extend the lifetimes T-1(C-13) of the enhanced C-13 polarization during and after transfer from the polarizer to the NMR or MRI system. This extends time scales over which metabolic processes and chemical reactions can be monitored.
Hikari Ananda Infinity Yoshihara, Arianna Ferrari