Recent Developments in Deep Eutectic Solvents Applications in Liquid Chromatography: 2019-2025.

Deep eutectic solvents (DES) are used as mobile phase and stationary phase modifiers, or as for the stationary phase itself for thin layer/liquid/supercritical chromatography. Their specific properties can improve the separation selectivity, reduce peak tailing, and shorten the separation time. In terms of environmental impact, the advantages of DES are based on their biodegradability, recyclability, and stability in terms of mechanical/chemical/thermal properties. The disadvantages are related to higher viscosity and degradation in aqueous solutions. This review focuses on works that have been published since 2019, the year the excellent comprehensive review by Cai and Qiu was printed. Selected parameters are discussed that should be considered when DES are preferred over commonly used mobile and stationary phases due to green chemistry trends, while taking into account their limitations in modern LC separations. This review also centres on critical aspects of DES applications in the field of liquid and supercritical fluid chromatographic separations.