Selective fractionation of sugar alcohols using ionic liquids

In this article, the solubility of linear sugar alcohols and inositols in selected ionic liquids (ILs), i.e., 1-hexyl-3-methylimidazolium chloride ([HMIM][Cl]), 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]), 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) and 1,3-dimethylimidazolium dimethylphosphate ([MMIM][Me2PO4]), has been investigated. The experimental results demonstrated widely divergent solubilities (in the 1.7-84.7%, w/w, range) for the several targeted carbohydrates in the different ILs evaluated, with [EMIM][OAc] and [MMIM][Me2PO4] providing the highest solubility values. These ILs gave also the best results when applied to the selective fractionation of sugar alcohols from other LMWC in 1:1 (w/w) binary mixtures (yields in the 60-98% range). These results show ILs as promising non-volatile and environmental friendly solvents for this type of fractionation process and suggest the interest of further investigation in this particular application field.