Ion-Exclusion Chromatography:

Similar to ion chromatography, it also employs ion-exchange columns to achieve separations. However, it differs from ion chromatography in that it is used for the separation of neutral species rather than ions as typically illustrated by the separation of simple carboxylic acids in Figure. A cation exchange resin in acidic form was used and elution was accomplished with dil HCl. The analytical column was followed by a suppressor column packed with a cation exchange resin in silver form where H⁺ were exchanged for Ag⁺ which then precipitated Cl^- thus removing the ions contributed by the eluent. The undissociated analyte acids were distributed between the mobile phase in the column and the immobilized liquid held in the ores of the ion packing. Ion-exclusion chromatography has found numerous applications for the identification and determination of acidic species in milk, coffee, wine and other commercial products. Similarly, weak bases and their salts can also be separated by using anion exchange column in OH^- form.