(720c) Sugaring-out. A Novel Phase Separation and Extraction System

In this study, we made a novel observation that by introducing a monomeric sugar or a disaccharide into an acetonitrile-water solution, the acetonitrile (ACN) can be separated from water to form a new phase. The upper phase was rich in ACN while the lower phase was aqueous. The ACN concentration in the upper phase increased when more sugar was added into the ACN-water mixture. The ability of different sugars to form an ACN-water two-phase system and the effect of glucose and xylose concentration on the phase separation were studied. The two-phase formation triggered by sugar addition was visualized with Sudan I. The distribution of syringic acid, furfural, para-coumaric acid, ferulic acid and 5-Hydroxymethyl furfural in the upper ACN phase and lower water phase was examined. The lower concentration limit for the two-phase formation for glucose and xylose at 1oC was 15 g/L and 25 g/L, respectively. At higher temperatures, the concentration needed for phase separation increased. Addition of polysaccharides (starch and dextran) did not result in phase separation. The distribution coefficient of the five organic compounds in the ACN-water two-phase system was in the range of 1.7-8.9 when the corresponding sugar concentration was 15-50 g/L. The phase ratio of the five organic compounds in the two-phase system was in the range of 0.1-0.5. In the Sudan I extraction test with a glucose-triggered ACN-water two-phase system, an extraction rate of > 80% was achieved when the glucose concentration was greater than 25 g/L. The new two-phase system may find applications in the separation of chemicals having different solubility in water and in ACN.