Partitioning of Amino Acids in Surfactant Based Aqueous Two-Phase Systems Containing the Nonionic Surfactant (Triton X-100) and Salts

The partitioning of three amino acids, L-phenylalanine, L-tryptophan and L-tyrosine, has been studied in surfactant-based aqueous two-phase systems (ATPS) of Triton X-100 + salts + H₂O at 298.15 K. Sodium citrate as an organic salt and magnesium sulfate as an inorganic salt were used to prepare the ATP systems. The effects of tie-line length and salt type on the partitioning of amino acids have been discussed. The results show that the partitioning behavior of the amino acids in the systems containing MgSO₄ and Na₃C₆H₅O₇ are significantly different, because increasing the tie-line length in MgSO₄ solutions leads to a decrease of the partition coefficient, whereas the opposite trend is found in Na₃C₆H₅O₇ solutions.