EXTRACTION EQUILIBRIA OF AMINO-ACIDS WITH DI-(2-ETHYLHEXYL) PHOSPHORIC-ACID

The extraction equilibria of various amino acids with di- (2-ethylhexy l)phosphoric acid(P-204) were studied in the lower pH range, P-204 rea cts with the cations of amino acids according to the stoichiometric ra tio determined by ionic valency, For monovalent cations, the reaction forming complex can be expressed as follows: A(+)+2(HL)(2)=AL(HL)(3)+H + The values of extraction equibibrium constant K-ex of several amino acids were obtained. The effects of some parameters on the distributio n ratio of amino acids were also studied.