Boosting 1H and 13C NMR signals by orders of magnitude on a bench

Sensitivity is often the Achilles’ heel of liquid-state nuclear magnetic resonance (NMR) experiments. This problem is perhaps most pressing at the lowest fields (e.g., 80 MHz 1H frequency), with rapidly increasing access to NMR through benchtop systems, but also sometimes for higher-field NMR systems from 300 MHz to 1.2 GHz. Hyperpolarization by dissolution Dynamic Nuclear Polarization (dDNP) can address this sensitivity limitation. However, dDNP implies the use of massive and complex cryogenic and high-field instrumentation which cannot be installed on the bench. We introduce here the very first compact helium-free 1 Tesla tabletop polarizer as a simple and low-cost alternative. After freezing and polarizing the frozen analyte solutions at 77 Kelvin, we demonstrate 1H signal enhancement factors of 100, with rapid 1 second build-up times. The high polarization is subsequently transferred by 1H→13C cross-polarization (CP) to 13C spins. Hyperpolarization in such a simple benchtop polarizer, in combination with the use of hyperpolarizing solid matrices (HYPSOs) may open the way to replenishable hyperpolarization throughout multiple liquid-state NMR experiments.