Evaluation of cyclodextrin‐ and cyclofructan‐based chiral selectors for the enantioseparation of psychoactive substances in capillary electrophoresis

Abstract

During this study, a simple and easy-to-prepare electrophoretic method was developed for the enantioseparation of amphetamine and cathinone derivatives. Different types of β-cyclodextrin and cyclofructan-based chiral selectors (CSs), both native and derivatized, were utilized, and the most effective ones, in terms of resolution and analysis time, were identified. In addition, several electrophoretic parameters, such as background electrolyte concentration and pH, and CS concentration, were examined to optimize the separation conditions. Under the optimal electrophoretic conditions, 10 psychoactive substances were enantiomerically separated using 1 mM sulfated cyclofructan-6 (SCF-6) for the amphetamine derivatives and 1 mM sulfated cyclofructan-7 (SCF-7) for the cathinone derivatives dissolved in an aqueous solution of 20-mM monobasic sodium phosphate at pH 2.5, a temperature of 25 • C, and an applied voltage of 25 kV. In addition, the method was validated by estimating the intra-and interday precision.

Cyclodextrin-Enabled Enantioselective Complexation Study of Cathinone Analogs

“…In the case of the promising CD systems, CE conditions were optimized regarding the type (phosphate–NaOH, acetate–HCl, acetate–TRIS), pH (2.5–7.0), and concentration (20–100 mM) of the background electrolyte, the injection parameters, and the selector concentration (0.5–10 mM). In the literature, two main BGEs are used for the CD-based chiral analysis of diverse sets of cathinone analogs: the 10–100 mM phosphate buffer pH 2.5(–3.0) [ 4 , 7 , 9 , 11 , 12 , 13 , 14 , 16 , 17 , 30 ], and the pH 4.5 acetate buffer [ 5 , 6 , 8 ]. In our measurements, the best peak shapes and optimal analysis time were provided by 20 mM acetate buffer pH 4.5.…”

“…Cathinone derivatives are chiral compounds; in the literature, several chiral method developments using CDs have been carried out so far for diverse sets of cathinone derivatives, among which the majority is capillary electrophoretic (CE) methods of solid samples [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ], but methods from urine [ 16 ] or hair samples [ 17 ] are also present, and an RP-HPLC method using sulfated-β-CD as chiral selector added to the mobile phase is available [ 18 ]. The enantioselective analysis of these compounds is not only important from a scientific point of view but can also greatly facilitate the regulatory control of samples.…”

Capillary Electrophoresis: A Three-Year Literature Review

“…Multiple chiral selectors can provide unique enantioselectivities toward specific chiral compounds, which would have been difficult to achieve with a single chiral selector alone. Therefore, this approach is particularly useful when the separation of complex chiral mixtures is required and when a single chiral selector in the separation medium does not provide the desired level of enantiomeric separation. − …”

Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications—Updated and completely revised edition

“…All mentioned factors need to be optimized in the presence of CS as a buffer additive or coated/immobilized into a stationary phase and in a dynamic coating system to achieve selective and effective separation. Some new developments in chiral CE and applications are listed in Table 4 [96,[121][122][123][124][125][126][127][128][129][130][131][132][133][134][135].…”