Final iron abundances as a function of REW (left panels) and EP (right panels) for five stars (BD+264251, HD 102200, HD 106038, HD 126681, HD 175305) analysed in this work. Open circles indicate neutral lines while filled red circles indicated ionised lines. A linear regression fit to the neutral lines is performed for all lines (indicated with a black dash-dotted line) and for high-EP lines (EP ≥ 2 eV, indicated by a blue dotted line). The slope of the trend and its standard error are indicated at the top of each panel. A slope is considered to be significant if its absolute value is larger than the standard error. The effective temperature and surface gravity for each star is also indicated at the bottom of the left panels for reference. Dashed red line indicates the mean of the ionised lines.