Abstract The F19(t, p)F21 reaction has been studied by magnetic analysis and the excitation energies of 19 states have been determined. The Q-value of the reaction was measured to be 6.219±0.012 MeV which is consistent with F21 having a mass excess of −0.045±0.012 MeV. Excitation energies of 26 states of Na25 have also been measured using the Na23(t, p)Na25 and the Mg26(t, α)Na25 reactions. The Q-value of the former reaction was found to be 7.492±0.012 MeV and that of the latter to be 5.664±0.012 MeV. Both Q-values are consistent with a Na25 mass excess of −9.357±0.008 MeV. (Mass excesses are referred to the C12 scale).