ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Evaluation of the synergistic effect of amino acid deep eutectic solvents as additives for enantioseparation in nonaqueous capillary electrophoresis

Hongqing Xu, Xiaofei Ma, and Xiaomin Guan

Department of Pharmacy, Nantong First People’s Hospital and Nantong Hospital of Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Nantong, People’s Republic of China

E-mail: maxiaofei1113@163.com

Received: 18 February 2025  Accepted: 8 November 2025

Abstract:

The synergistic effects between deep eutectic solvents (DESs) and chiral selectors in aqueous capillary electrophoresis (CE) for enantioseparation has been well validated. However, such synergistic effects have not been thoroughly validated in nonaqueous capillary electrophoresis (NACE). In this work, two amino acid deep eutectic solvents (AADES) were prepared as additives in NACE and the synergistic separation systems with native β-cyclodextrin (β-CD) for the enantioseparation of several dansyl amino acids (Dns-AA). Compared to the unmodified β-CD system, the separation of Dns-AA was significantly improved in the synergistic system. We optimized several key separation parameters and explored the chiral recognition mechanism using molecular modeling technique. Additionally, we calculated the binding constants of the enantiomers with β-CD in the two systems using dansyl alanine as a model analyte. In the presence of AADES, the Dns-AA enantiomers formed tighter complexes with β-CD. This study demonstrated that the proposed AADES exhibited good synergistic effects with β-CD in NACE, and they were proved to be promising additives for enantioseparation.

Graphical abstract

Keywords: Amino acids; β-cyclodextrin; Deep eutectic solvents; Enantioseparation; Nonaqueous capillary electrophoresis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04494-7

Chemical Papers 80 (2) 1861–1869 (2026)