Equivalent widths of 23 wide binaries

The use of a line-by-line differential analysis technique between the components of each pair allows us to reach errors of about 0.02dex in the iron content difference.

Most of the pairs have abundance differences lower than 0.02dex and there are no pairs with differences larger than 0.07dex. The four cases of differences larger than 0.02dex may be spurious because of the larger error bars affecting pairs with large temperature difference, cold stars and rotating stars.