Liquid Ion Exchangers:

It was pointed out which high molecular weight amines and quaternary ammonium salts behave as liquid anion exchangers. That extracts the anions and anionic metal complexes. With a same analogy, a few authors classify alkylphosphoric acids, sulphonic acids and carboxylic acids as liquid cation exchangers. It was also pointed out at the similar time which this analogy should not be extended too far. Besides other complications, the operation of transfer of solute in solvent extraction and ion exchange chromatography is different. Therefore, one situation remains to be considered while these extractants mostly high molecular weight amines are loaded on inert supports and the supports are used in columns for separations. This is categorized under the head of extraction chromatography. A variety of metal ion separations are achieved using this method. In this context, there might be some justification for having liquid ion exchangers as a distinct class of ion exchangers.