Method for separating and purifying amino acid

摘要

This is a method for separating or purifying an amino acid from a mixture including other substance such as an inorganic salt other than the amino acid and/or a mutual mixture of amino acids including the amino acid by means of piezo-dialysis employing an amphoteric ion exchange membrane. This membrane is made from a ternary block copolymer having a molecular structure of straight chain in which first macro-molecule with a cation exchange group, second macromolecule with an anion exchange group and third macromolecule without ion exchange group are linked together.