Enantiomeric Separation of Synthetic Amino Acids Using Capillary Zone Electrophoresis

Abstract

Three chiral selectors, sulfated α‐cyclodextrin (SAC), sulfated β‐cyclodextrin (SBC), and carboxymethyl β‐cyclodextrin (CMBC) were examined as run buffer additives for the separation of sixteen racemic synthetic amino acids and three prepared mixtures of chiral synthetic amino acids, using capillary zone electrophoresis. Seventeen of the nineteen synthetic amino acids were enantiomerically separated and fourteen of them were optimized to baseline using one or more chiral running buffer additives. SAC, with eleven baseline and three partial separations, and SBC, with ten baseline and four partial separations, were found to be more broadly useful than CMBC. Increasing the chiral selector concentration improved the enantioresolution, but also produced longer analyses times. Addition of organic modifier (ethanol) increased migration times and decreased enantiomeric resolution. Increasing the pH of the run buffer decreased analyses time as well as resolution. Decreasing the applied voltage generally improved resolution.