Characterization of naphthalene dicarboxylic acids. 3. Separation on Dowex 1-× 8 anion-exchange resin

The 10 isomeric naphthalene dicarboxylic acids have been eluted from a column of Dowex 1 anion exchange resin using potassium bromide 0–1 M. By comparison of their behaviour, it now seems possible that failure to observe these acids in the sub-humic acids of Lawson and co-workers may have been due to use of ions of strength insufficient for their elution.