Deep eutectic solvents are not only effective extractants

Deep eutectic solvents are compounds formed by a donor and an acceptor of hydrogen bond; and are in liquid state at ambient temperature. They are non-volatile, with high thermal stability and readily dissolve many organic and inorganic compounds. They are recognized as green and cheap alternatives to ionic liquids. They have recently appeared in analytical practice but have already found wide application in various fields of analytical chemistry; mainly as effective extractants. However, their use as extractants does not limit the scope of their capabilities. This review is primarily devoted to the description of new possibilities of applications of deep eutectic solvents in analytical chemistry; including such areas as chromatographic separation, electrochemical analysis, sample preparation, synthesis and modification of new sorption materials. In addition, the stability of deep eutectic solvents, terminology, classification, further trends and some errors and inaccuracies associated with their applications are discussed. (C) 2020 Elsevier B.V. All rights reserved.