  The Q-value of the double-electron capture in Cd-108 has been determined to
be (272.04 +/- 0.55) keV in a direct measurement with the double-Penning trap
mass spectrometer TRIGA-TRAP. Based on this result a resonant enhancement of
the decay rate of Cd-108 is excluded. We have confirmed the double-beta
transition Q-values of Cd-106 and Pd-110 recently measured with the
Penning-trap mass spectrometers SHIPTRAP and ISOLTRAP, respectively.
Furthermore, the atomic masses of the involved nuclides Cd-106, Cd-108, Cd-110,
Pd-106, Pd-108 and Pd-110 have been directly linked to the atomic mass
standard.
