  In this work we make use of available Integral Field Unit (IFU) spectroscopy
and slit spectra of several nearby galaxies. The pre-existing empirical R and S
calibrations for abundance determinations are constructed using a sample of HII
regions with high quality slit spectra. In this paper, we test the
applicability of those calibrations to the IFU spectra. We estimate the
calibration-based abundances obtained using both the IFU and the slit
spectroscopy for eight nearby galaxies. The median values of the slit and IFU
spectra-based abundances in bins of 0.1 in fractional radius Rg (normalized to
the optical radius) of a galaxy are determined and compared. We find that the
IFU and the slit spectra-based abundances obtained through the R calibration
are close to each other, the mean value of the differences of abundances is
0.005 dex and the scatter in the differences is 0.037 dex for 38 datapoints.
The S calibration can produce systematically underestimated values of the IFU
spectra-based abundances at high metallicities, the mean value of the
differences is -0.059 dex for 21 datapoints, while at lower metallicities the
mean value of the differences is -0.018 dex and the scatter is 0.045 dex for 36
data points. This evidences that the R calibration produces more consistent
abundance estimations between the slit and the IFU spectra than the S
calibration. We find that the same calibration can produce close estimations of
the abundances using IFU spectra obtained with different spatial resolution and
different spatial samplings. This is in line with the recent finding that the
contribution of the diffuse ionized gas to the large aperture spectra of HII
regions has a secondary effect.
