To measure the polarization achieved on the hydrogenated substrate, the NMR tube used for the reaction was placed into the high field magnet immediately after the field cycle. A comparison between the hyperpolarized and thermal equilibrium spectra is shown in Fig. . The resulting signal enhancement factor was measured to be 20,300 at 14.1 T, corresponding to a polarization level of 25%. The ratio of peak integrals between fumarate and succinate indicates 89% fumarate yield (45 mM), and 11% succinate yield (5 mM), and there is no detectable unreacted starting material. We have set an upper bound on the concentration of unreacted starting material at <0.4 mM.