Enantiomeric separation of nefopam and cathinone derivatives using a supramolecular deep eutectic solvent as a chiral selector in capillary electrophoresis
Katerina A. Ioannou, Μαρία Γεωργίου, Georgia D. Ioannou, Atalanti Christou, Ioannis J. Stavrou, Martin G. Schmid, Constantina P. Kapnissi‐Christodoulou
Abstract
Abstract The present study investigates the utilization of a supramolecular deep eutectic solvent (SUPRADES), consisting of sulfated‐β‐cyclodextrin (S‐β‐CD) and citric acid (CA), as a chiral selector (CS) in capillary electrophoresis for the enantiomeric separation of nefopam (NEF) and five cathinone derivatives (3‐methylmethcathinone [3‐MMC], 4‐methylmethcathinone [4‐MMC], 3,4‐dimethylmethcathinone [3,4‐DMMC], 4‐methylethcathinone [4‐MEC], and 3,4‐methylendioxycathinone [MDMC]). A significant improvement in enantiomeric separation of the target analytes was observed upon the addition of S‐β‐CD‐CA to the background electrolyte (BGE), leading to a baseline separation of all analytes. In particular, the optimum percentage of S‐β‐CD‐CA, added to the BGE, was determined to be 0.075% v/v for NEF ( R s = 1.5) and 0.050% v/v for three out of five cathinone derivatives ( R s = 1.5, 1.6, and 2.4 for 3‐MMC, 4‐MEC, and 3,4‐DMMC, respectively). In the case of 4‐MMC and MDMC, a higher percentage of the CS, equal to 0.075% and 0.10% v/v, respectively, was required to achieve baseline separation ( R s = 1.5, 1.9 for MDMC and 4‐MMC, respectively). The outcomes of the present study highlight the potential effectiveness of using SUPRADES as a CS in electrophoretic enantioseparations.