LAUSR

Abstract Deep eutectic solvents (DESs) are currently being used in different sectors, such as electrochemistry, electrodeposition, organic synthesis, nanoparticle preparation, bioactive compound separation, etc. Their use in analytical chemistry has only recently begun to expand. Despite the publication of a sufficient number of DES-based analytical extraction procedures, some details, such as interaction of DES with the sample and target analytes as well as with water are insufficiently explored and theoretically explained. Here we discuss the role of water in DES-based extraction in terms of analytical chemistry, especially for the pre-treatment of solid samples. We believe that this review will benefit those who have linked their research with DESs and will enable them to speed up their work.