Separation of Indole-3-acetic Acid from Tryptophan by Bulk Liquid Membrane

Background: Indole-3-acetic acid (IAA) is an important growth hormone for plants obtained by biosynthesis from tryptophan. Aim: In this paper was studied the competitive transport of two biologically active compounds, indole-3-acetic acid (IAA) and tryptophan (TRP), through a liquid membrane. Methods: The separation of the two compounds was obtained using a hybrid liquid membrane system having trioctylphosphine oxide (TOPO) as a carrier. Results: The most important operational parameters of the system, and pH influence on the efficiency of the transport process, in correlation with the speciation diagrams of the two compounds: TRP and IAA, were studied. The evaluation of the transport process was performed by calculating the composition of the phases at the end of the transport process and the organic substrate flow at the membranes exit. Conclusion: Due to the transport efficiency of over 90% in the case of IAA and the high selectivity at the transport between IAA and TRP, the procedure can be applied for the preparation of a sample containing these analytes.