Britannica Sources used in this answer

How is ion-exchange chromatography used to analyze amino acids?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

chemical structure of cation exchanger — ion-exchange reaction Figure 1: Chemical structure of cation exchanger. The exchangeable ions are marked ⁺. The whole structure is permeated by solvent molecules, usually water (not shown).

Ion-exchange chromatography is a standard laboratory technique used to analyze mixtures of amino acids, such as those derived from blood serum or the hydrolysis of proteins.12

The process functions through the following steps:

Column Preparation: The mixture is passed through columns containing cation-exchange resin. The solutions are maintained in a sufficiently acidic state to ensure the amino acids exist at least partially in their cationic (positively charged) forms.1
Separation: As the mixture moves through the resin, the amino acids are separated based on their chemical properties.12
Quantification: Once separated, the concentration of each individual amino acid is determined automatically using light-absorption methods.1

This analytical procedure is highly efficient, allowing the 20 principal amino acids to be separated within a few hours. Because of its reliability, this method is frequently utilized in clinical diagnosis.1