Sharif Digital Repository

The partition coefficients of L-Lysine HCL were measured in polymer-salt aqueous two-phase systems. These systems contain polyethylene glycol with nominal molecular weight of 4000 or 10000 and two different salts (di-potassium hydrogen phosphate or tri-sodium citrate 5,5-hydrate). The experimental data were obtained at temperatures 293.15, 298.15 and 303.15 K. The effects of temperature, pH, polymer and salt concentrations, polymer molecular weight and salt type on the partitioning of L-Lysine HCL were also studied. The results showed that salt concentration has a significant effect on the partition coefficient while temperature has a low effect. The experimental partition coefficients of... 

The aqueous two phase systems provide a suitable environment for separation and purification of biological compounds. Because both phases are water rich and biomolecule remain active in them. In this work, the partition coefficients of Cephalexin in polymer-salt aqueous two-phase systems have been measured. The experimental results were obtained at three various temperatures (37.2, 34.2 and 28.2) C and in each temperature, two salt (K2HPO4, Na3Cit) and two polymer with different molecular weight (4000, 10000) are investigated. According to the two phase analysis, the effect of different factors on tie line of systems is studied. It is observed that with increasing the PEG molecular weight,... 

In this research, the partitioning of Penicillin G-Acylase in aqueous two-phase systems (ATPS) containing poly ethylene glycol (PEG) 20000 or 35000 and potassium di-hydrogen phosphate (KH2PO4) or sodium citrate (C6H5Na3O7.5H2O) is measured at three temperature (301.2, 307.2 and 310.2) K. The effects of temperature, polymer molecular weight, polymer and salt concentrations on partitioning of Penicillin G in the aqueous two-phase systems are studied. The experimental data showed that composition of salt has a large effect on partitioning of Penicillin G in ATPS and temperature of system has small effect on the partitioning. The modified local composition model was used to obtain the activity... 

The effects of adding nanoparticles in partitioning of α-amylase in polymer/salt aqueous two phase system (ATPS) was studied in this research. First the binodal curves of magnesium sulfate salt with PEGs 2000,3000,4000,6000 and 10000 at 23 ° C has been plotted and the suitable system which was PEG 6000/ magnesium sulfate has been selected for studying the partitioning of enzyme. Thereupon the partition coefficient of α-amylase was measured and then effect of adding silica and graphene oxide nanoparticles was investigated. It was observed that nanoparticles caused a dramatic increase in partition coefficient and yield recovery (of top phase). For further investigation the partitioning of... 

In this study, aqueous two-phase systems (ATPS) containing Tween 20 as a biocompatible nonionic surfactant and three different salts (NH4HPO4, NH4CH3COO and Mg(CH3COO)2 ) were prepared and their extractive potential for Lysozyme enzyme was evaluated. These systems have surfactant-rich top phase and salt-rich bottom phase. Phase equilibrium diagrams at 23 ° C were obtained by using the cloud point method and the results were successfully fitted to the Merchuk correlation and their trends were correlated with the effective excluded volume (EEV) parameter. Afterward, the partitioning behavior of the lysozyme and its extraction efficiency in the systems of Tween 20/diammonium hydrogen phosphate,...