Central composite design in the chiral analysis of amphetamines by capillary electrophoresis

Abstract

We have studied a central composite design for the chiral separation of amphetamines using capillary electrophoresis. Five variables, i.e., buffer concentration, pH, chiral selector concentration, temperature, and applied voltage, were investigated. Enantiomeric resolutions as well as analysis time and generated power were established as responses for each experiment. A model of each response was obtained by multiple regression of a quadratic-degree mathematical expression. From the models, we determined the most favorable conditions for the chiral separation by optimizing the resolution and setting the other responses at threshold values. Results were compared with a previous study in which a systematic investigation of the operating parameters was carried out. In order to visualize the robustness of the method, response surfaces were drawn for the significant variables. We have concluded that experimental designs offer a rapid means of optimizing several variables and provide an efficient test for the robustness of the analytical method.

Fast chiral separation of drugs using columns packed with sub‐2 μm particles and ultra‐high pressure

“…2B). As already demonstrated CZE, 36,37 HP-b-CD is the best chiral in selector for the separation of amphetamines. In UHPLC, a concentration of 20 mM HP-b-CD was chosen as the best compromise between enantioselectivity and backpressure for all tested compounds.…”

Determination of Optimal Technological Parameters of a Compaction Process: Case Study

“…As the natural factor levels at treatments no. 17 to 25 had not been chosen properly in the experiment reported in [5], coded levels of x 2 to x 4 in these rows differ from the standard design described in the fundamental books [10,11,12] or in papers [13,14,15,16,17]. This fact may have some minor effect to the precision of predictions.…”

Applications de l'électrophorèse capillaire en toxicologie clinique et médico-légale

“…Le rôle de TEC dans la détermination des formes énantiomèriques devient prépondérant (20,45,60). Lurie (60) étudie l'effet de sélecteurs chiraux anioniques sur la CEC d'un mélange chirat de phénylé-thylamines et d'impuretés neutres non chirales présents dans de la méthamphétamine illicite.…”

“…L'équipe de Thormann est certainement encore la plus active dans l'analyse des milieux biologiques (10-12) et il décrit dans une revue de la littérature sur les années 1997 et 1998 les progrès récents de TEC et les applications en routine en toxicologie clinique et médico-légale. Des études plus spécifiques se développent : TEC est en train de devenir l'approche la plus commune pour l'analyse chirale de nombreux médicaments et substances illicites (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) (28). Cependant, l'injection directe de l'échantillon reste peu appliquée à l'analyse toxicologique de prélè-vements biologiques en raison de la faible concentration des xénobiotiques.…”