Abundance ratios as a function of metallicity for our sample of 120 dwarf stars of the thin-disk population. Stars with planets are represented by black symbols. For sodium, the abundance ratios from both spectral synthesis and equivalent widths determination are plotted. The 95% confidence intervals (solid lines) around linear regressions, and their respective correlation coefficients (r) are also shown. The linear regressions were derived either for [Fe/H] ≤ 0, [Fe/H] ≥ 0, or for the whole metallicity range, depending on which one has the more significant slope.