Enantioseparation by Chiral Ligand-Exchange Capillary Electrophoresis

Chiral ligand-exchange capillary electrophoresis is a relatively cheap and flexible format of capillary electrophoresis. It separates chiral analytes with a metal complex chiral selector that is composed of a metal ion and either homogeneous or heterogeneous chiral ligands (in respect of analytes). The analytes to be separated are required to possess the ability to coordinate with the metal ion, commonly containing N and/or O atoms, for example, amino acids or amino alcohols. In present chapter we take the separation of dansyl dl-amino acids as a key example to guide through the setup of a chiral ligand-exchange capillary electrophoresis enantioseparation protocol. The critical working conditions emphasized include the selection of metal ion, pH window, the ligand-to-metal ratio and/or the concentrations of the complex and electrolytes. In addition, trouble-shooting advice is given such as the way to overcome baseline drifting.