  The purpose of this work is to make available new gas-phase oxygen abundance
measurements for a serendipitous sample of 27 galaxies with redshift
0.35<z<0.52. We measured the equivalent widths of the [O II]{\lambda}3727,
H{\beta}, and [O III]{\lambda}{\lambda}4959, 5007 emission lines observed in
the galaxy spectra obtained with the Visible Multi-Object Spectrograph mounted
at the Very Large Telescope. For each galaxy, we derived the
metallicity-sensitive emission lines ratio R23, ionization-sensitive emission
lines ratio O32, and gas-phase oxygen abundance 12+log(O/H). The values of
gas-phase oxygen abundance 12+log(O/H) we obtained for the sample galaxies are
consistent with previous findings for galaxies at intermediate redshift.
