| abstract |
The invention provides a process for the separation of amino acids and their salts from impurities contained in an aqueous feed solution containing the same, wherein the solution has a pH value of pH > pl, in the case of acidic amino acids, has a pH value of pH < pl in the case of basic amino acids, and has a pH value of pl-2 < pH < pl+3 in the case of neutral amino acids, and wherein pl is the isoelectric point, comprising: a) bringing the feed solution into contact with a substantially immiscible extractant phase comprising an amine and an acid, both of which are substantially water immiscible in both free and salt forms to extract amino acid and salts thereof into the phase, wherein the extraction is carried out while the feed solution is within two pH units of the initial pH of the feed solution; and b) backwashing the extractant phase with a substantially neutral aqueous system to recover substantially all of the extracted amino acid and the extracted salts thereof. |