Process for separation and purification of a dicarboxylic acid containing mixture

A method for separation of a carboxylic acid of interest from a mixture containing this carboxylic acid among other carboxylic acids, comprising:

• providing a carboxylic acid-containing mixture containing at least 35 wt. % of said carboxylic acid of interest based on the total carboxylic acid content of the mixture;
• and running an extraction of said carboxylic acid-containing mixture through a chromatographic column configured with an amphoteric resin, such that the carboxylic acid product elutes from the carboxylic acid-containing mixture, wherein
• said carboxylic acid of interest is glucaric acid or gluconic acid and the mixture is a mixture of either or both of these with still other carboxylic acids;
• and
• said amphoteric resin has a surface characterized as having both weakly acidic positive and strongly basic negative functional groups on a polymeric backbone.