CENTRAL COMPOSITE DESIGN IN THE CHIRAL ANALYSIS OF AMPHETAMINES BY CAPILLARY ELECTROPHORESIS

We have studied a central composite design for the chiral separation o f amphetamines using capillary electrophoresis. Five variables, i.e., buffer concentration, pH, chiral selector concentration, temperature, and applied voltage, were investigated. Enantiomeric resolutions as we ll 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 mo dels, we determined the most favorable conditions for the chiral separ ation 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 ou t. In order to visualize the robustness of the method, response surfac es were drawn for the significant variables. We have concluded that ex perimental designs offer a rapid means of optimizing several variables and provide an efficient test for the robustness of the analytical me thod.