Dual systems of cyclodextrins in Electrokinetic Chromatography: recent applications to stereoselective separations

Electrokinetic Chromatography (EKC) constitutes a powerful technique for chiral analysis. Cyclodextrins (CDs) are the most widely employed chiral selectors in EKC due to their high discrimination power and availability. Single systems of CDs can provide the necessary chiral discrimination but sometimes do not allow to obtain the desired stereoselective separation. Dual-CDs systems consisting of a mixture of two CDs constitute an interesting option to improve the chiral resolution. The presence of two CDs can increase the complexity of method optimization. However, modelling-based optimization of a separation has shown to be an effective alternative to find the appropriate experimental conditions for a given chiral separation by EKC. In this article, the models reported to describe a separation by EKC with dual-CDs systems are presented, and the applications of these dual systems to the stereoselective separation of individual analytes or multicomponent mixtures by EKC are reviewed covering the period 2017-2025. • Theoretical models describing the separation by EKC with dual-CDs systems reviewed • Selectivity enhancement and method optimization in chiral EKC with dual-CDs systems • Characteristics of chiral strategies and applications in the period 2017-2025 • Drugs, pesticides, organic acids, amino acids or ferrocene derivatives separated • Analysis of pharmaceutical, biological, agrochemical, and environmental samples