More Than 50 % 13C Polarization in Solution by the DNP-NMR Method: 200,000-Fold Enhancement Compared to 3 T and Room Temperature

Jan Henrik Ardenkjaer-Larsen¹, Sven Macholl¹, Haukur Johannesson¹

The DNP method for hyperpolarizing nuclear spins in molecules in solution can still be significantly improved in terms of achieved polarization. So far, a polarization of 10-30 % has typically been obtained in the liquid state with the current instrumentation. In this work we demonstrate two different means of further enhancing the polarization in the solid state. One method is by changing the magnetic properties of the sample, the other is by changing the field and temperature of the polariser. The methods are exemplified by several molecules of particular biological interest and liquid state polarization of more than 50 % is demonstrated.