Liquid state (Overhauser) Dynamic Nuclear Polarization (DNP) experiments have been performed at high magnetic fields (9.4 T) on aqueous solution of 14N-TEMPOL nitroxide radicals. To determine the saturation factor of the electron spin, the 1H paramagnetic shift as a function of the microwave power was measured as previously reported . We could show that the paramagnetic shift depends on the 14N-TEMPOL radical concentration. The suppressed paramagnetic shift can be determined by measuring the NMR line shift as function of the applied microwave power, which allows a quantitative determination of the DNP saturation factor.
 P. Neugebauer, J. G. Krummenacker, V. P. Denysenkov, G. Parigi, C. Luchinat and T. F. Prisner, Phys. Chem. Chem. Phys., 15, 6049 (2013).