Perez Linde, A.J., et al., Dynamic nuclear polarization enhancement of protons and vanadium-51 in the presence of pH-dependent vanadyl radicals. Magn Reson Chem, 2015. 53(2): p. 88-92.
We report applications of dynamic nuclear polarization to enhance proton and vanadium-51 polarization of vanadyl sulfate samples doped with TOTAPOL under magic angle spinning conditions. The electron paramagnetic resonance response stemming from the paramagnetic (51) V species was monitored as a function of pH, which can be adjusted to improve the enhancement of the proton polarization. By means of cross-polarization from the proton bath, (51) V spins could be hyperpolarized. Enhancement factors, build-up times, and longitudinal relaxation times T1 ((1) H) and T1 ((51) V) were investigated as a function of pH. Copyright (c) 2014 John Wiley & Sons, Ltd.