  Isomeric yield ratios for the odd-$A$ isotopes of $^{119-127}$Cd and
$^{119-127}$In from 25-MeV proton-induced fission on natural uranium have been
measured at the JYFLTRAP double Penning trap, by employing the Phase-Imaging
Ion-Cyclotron-Resonance technique. With the significantly improved mass
resolution of this novel method isomeric states separated by 140 keV from the
ground state, and with half-lives of the order of 500 ms, could be resolved.
This opens the door for obtaining new information on low-lying isomers, of
importance for nuclear structure, fission and astrophysics. In the present work
the experimental isomeric yield ratios are used for the estimation of the
root-mean-square angular momentum ($J_\mathrm{rms}$) of the primary fragments.
The results show a dependency on the number of unpaired protons and neutrons,
where the odd-$Z$ In isotopes carry larger angular momenta. The deduced values
of $J_\mathrm{rms}$ display a linear relationship when compared with the
electric quadrupole moments of the fission products.
