Partitioning of amino acids in the novel biphasic systems based on environmentally friendly ethyl lactate

For the first time, we report on the performance of biphasic system composed of ethyl lactate, water and inorganic salt (K3PO4, K2HPO4 and K2CO3) for the separation of amino acids (L-phenylalanine, L-tryptophan and L-tyrosine) from their aqueous solutions. Cloud points (solubility curve) and tie-lines for three ternary (ethyl la ctate + water + inorganic salt) systems at 298.2 K and 313.2 K at atmospheric pressure were determined. For certain composition range, these mixture exhibit biphasic systems – top and bottom phases rich in ethyl lactate and salt, respectively. Partition coefficients of amino acids and their extraction efficiencies, as essential parameters for design of any separation process, were measured at two temperatures – 298.2 K and 313.2 K. The maximum values of partition coefficients were observed for the system containing K3PO4: 3.5, 3.7 and 11.9 for L-phenylalanine at 313.2 K, L-tyrosine at 298.2 K and L-tryptophan at 313.2 K, respectively. The obtained results clearly showed that the biphasic systems based on ethyl lactate are suitable for the efficient and sustainable recovery of amino acids from solutions with water.