Novel Aqueous Two-phase Systems Formed by Biocompatible and Biodegradable Polysaccharides and Acetonitrile

RESUMO –In this work, it is shown that aqueous two-phase systems can be formed by the combination of acetonitrile and polysaccharides, namely dextran biopolymers. The respective ternary phase diagrams were determined at 25 oC for the systems composed of water + acetonitrile + dextran. The effect of the dextran molecular weight was also ascertained toward their ability to undergo liquid-liquid demixing. An increase in the dextran molecular weight favors the phase separation. In general, acetonitrile is enriched in the top phase while dextran is majorly concentrated in the bottom phase. The applicability of this new type of two-phase systems as liquid-liquid extraction approaches was also evaluated by the study of the partition behavior of a well-known antioxidant, namely vanillin, and used here as a model biomolecule. The optimized conditions led to a recovery of vanillin of 70.7% at the acetonitrile-rich phase.