  The correlation between the breaks in the metallicity distribution and the
corotation radius of spiral galaxies has been already advocated in the past and
is predicted by a chemo-dynamical model of our Galaxy that effectively
introduces the role of spiral arms in the star formation rate. In this work we
present photometric and spectroscopic observations made with the Gemini
Telescope for three of the best candidates of spiral galaxies to have the
corotation inside the optical disk: IC0167, NGC1042 and NGC6907. We observed
the most intense and well distributed \hii regions of these galaxies, deriving
reliable galactocentric distances and Oxygen abundances by applying different
statistical methods. From these results we confirm the presence of variations
in the gradients of metallicity of these galaxies that are possibly correlated
with the corotation resonance.
