From The DNP-NMR Blog:
Fast-field-cycling relaxometry enhanced by Dynamic Nuclear Polarization
Neudert, O., et al., Fast-field-cycling relaxometry enhanced by Dynamic Nuclear Polarization. Microporous and Mesoporous Materials, 2015. 205(0): p. 70-74.
http://www.sciencedirect.com/science...87181114003941
Fast-field-cycling (FFC) NMR relaxometry experiments enhanced by in-situ Dynamic Nuclear Polarization (DNP) were performed for 1H and 13C nuclear spins with a setup based on a commercial electronically switching FFC relaxometer and a recently-built Alderman–Grant type microwave resonator for 2 GHz. DNP-enhanced 1H relaxation dispersion profiles were compared to reference measurements and literature data in order to prove the reliability of DNP-enhanced relaxometry data. The method was then used to investigate the paramagnetic nuclear spin relaxation of 13C in a benzene-13C6,D6 solution of nitroxide radicals. Dispersion profiles of good quality were obtained within 2 h of measurement time from a comparatively small sample of 60 ?l. As a prospect for future applications, DNP experiments with a high-molecular weight Poly(butadiene-1,4) melt and BDPA radical were carried out at 2 GHz and 9.7 GHz microwave frequency, showing solid effect DNP enhancements. In-situ hyperpolarization by DNP may provide extended possibilities for FFC relaxometry, e.g. by allowing enhanced detection of dilute or insensitive nuclear spins, additional selectivity or faster measurements of small samples.
Go to
The DNP-NMR Blog for more info.