EXTRACTION EQUILIBRIA OF AMINO-ACIDS WITH QUATERNARY AMMONIUM SALT

The extraction equilibra of various amino acids with tri-n-octylmethylammonium chloride (TOMAC) were studied in the high pH range. TOMAC reacted with the anion of amino acid and OH- according to the stoichiometric ratio determined by ionic valency. The extraction equilibrium constants K(A) of various amino acids differed considerably and could be correlated well with each hydrophobicity scale. The highest K(A) value obtained for tryptophan was larger than the lowest value for glycine by a factor of about 260. These findings suggested that separation of amino acids is possible by utilizing the differences in K(A) values. The extraction equilibrium constants of inorganic anions which were present in the fermented broth was comparable to those of amino acids exhibiting a low degree of extraction.