Relaxometry of insensitive nuclei: Optimizing dissolution dynamic nuclear polarization

We report measurements of spin-lattice relaxation of carbon-13 as a function of the magnetic field ('relaxometry') in view of optimizing dissolution-DNP. The sample is temporarily lifted into the stray field above a high-resolution magnet using a simple and inexpensive 'shuttle'. The signals of arbitrary molecules can be observed at high field with high-resolution and sensitivity. During the dissolution process and subsequent 'voyage' from the polarizer to the NMR magnet, relaxation is accelerated by paramagnetic polarizing agents, but it can be quenched by using scavengers. (C) 2011 Elsevier Inc. All rights reserved.