Lloyd, L., et al., The effect of 13 C enrichment in the glassing matrix on dynamic nuclear polarization of [1- 13 C]pyruvate. Physics in Medicine and Biology, 2011. 56(5): p. N85-N92.
Dimethyl sulfoxide (DMSO) can effectively form a glassy matrix necessary for dynamic nuclear polarization (DNP) experiments. We tested the effects of 13C enrichment in DMSO on DNP of [1- 13 C]pyruvate doped with trityl radical OX063Me. We found that the polarization build-up time œÑ of pyruvate in 13 C-labeled DMSO glassing solution is twice as fast as the unenriched DMSO while the nuclear magnetic resonance enhancement was unchanged. This indicates that 13 C-13 C spin diffusion is a limiting factor in the kinetics of DNP in this system, but it has a minimal effect on the absolute value of polarization achievable for the target.