We determined oxygen abundances for the sample of SDSS galaxies with high masses using R3D, S3D, R2D, S2D, N and O3N2 calibrations. We investigated redshift–metallicity relation for oxygen abundances obtained by each calibration. We found that for galaxies with high stellar masses oxygen abundance obtained using all calibrations is increasing on the time interval from z = 0.5 to z = 0. However, the values of oxygen abundance enrichment rate significantly depend on adopted calibration and ranges from ~0.1 dex per unit redshift for R calibration to ~0.5 dex per unit redshift for O3N2 calibration.
