Liquid-liquid equilibria of aqueous two-phase systems (ATPS) containing triton-X100 and choline chloride at different temperatures

The use of aqueous two-phase systems (ATPSs) in processes of extraction and purification of strategic solutes such as proteins, metal ions, and nanomaterials have provided an important advance in the development of green separation technologies. In this research field, the discovery and the study of new ATPSs, especially those formed by nontoxic components, is a very important issue. In this work, a new ATPS formed by triton-X100 (TX-100), choline chloride (CC), and water was studied, and its phase diagrams were experimentally obtained at different temperatures (298.15 - 328.15 K). The concentrations of TX-100 and H2O were determined in each phase of the system using UV-vis spectroscopy and gravimetric analyses, respectively. The CC content in both phases was determined by mass balance. Interestingly, the shape of the binodal curves (Figure 1) was distinct from those reported for triton-based ATPSs described in the literature [1]. Moreover, the increase in the temperature of the system promoted an increase in the biphasic region (Figure 2), indicating an endothermic phase-separation process. All systems evaluated presented a top phase enriched with CC and a bottom phase enriched with TX-100, showing the segregation between these two components. Studies on the effect of hydrophilic chain length of triton on the ATPSs properties are under investigation in our laboratory. These new ATPSs are strategic for the extraction of biomolecules due to the biocompatibility of their components.