As a result of the above method, it was possible to significantly reduce the amount of water in the obtained DSILs: from 2.5 times (AB0.2) up to 6.5 times (AB0.9). The exact water contents after drying the systems are summarized in Table , they ranged from 0.6% (AB0.9) to 1.7% (AB0.2). It is likely that this is due to an increase in the strength of DSIL-water hydrogen bonding as the molar proportion of the MCPA anion increases. Drying process revealed that the remaining water must be therefore relatively highly bound with the ionic system. Further dehydration of such highly hygroscopic DSILs would require sophisticated methods, and conducting further analyses would have to take place in a dry inert gas atmosphere to achieve substantially reduced water contents (<2000 ppm) demonstrated in other reports. However, it should be borne in mind that the obtained ILs are intended for use in aqueous solutions, thus the increased water content in raw products does not constitute significant issue from a point of view of their industrial application.