Thin film composite membranes were prepared on polysulphone substrate by interfacial polymerization reaction of trimesoyl chloride separately with piperazine (Membrane I) or m-phenylene diamine (Membrane IV) or mixture of piperazine and m-phenylene diamine (90:10 and 65:35 w/w for Membrane II and III respectively). Among the four membranes the highest hydrophilicity and molecular weight cut-off values as well as highest negative surface potential were observed for polypiperazine trimesamide membrane (I). The thickness of the dense/ rejection layer observed for Membrane IV > III > II > I. SEM study revealed, homogeneous surface morphology for Membranes I and IV and heterogeneous morphology for Membranes II and III. The membranes were used for desalting of glutamic acid and glycine and also for the separation of these two amino acids from their mixture. Among the four membranes, Membrane I possessed the highest water flux and rejection ratio of 329:1 between MgSO4 and NaCl. For this membrane the rejections of glycine and glutamic acid are respectively 48.5% and 92.6% which are 22.1% and 66.2% higher than the rejection of NaCI. By proper monitoring of the solution pH it is possible to achieve >50% rejection difference between glutamic acid and glycine by this membrane. (C) 2015 Elsevier B.V. All rights reserved.