Chiral separation by capillary electrochromatography

Objective of this project is the development of methods for the separation of enantiomers by capillary electrochromatography (CEC). Capillary electrochromatography represents a hybrid between capillary electrophoresis (CE) and high performance liquid chromatography (HPLC). The advantages of CEC over HPLC are an improved separation efficiency with very sharp and narrow peaks. The separation is performed in packed or coated capillaries, whereby the transport of the mobile phase is caused by the electroosmotic flow. Based on the high efficiency, this method seems to be excellently suitable for the separation of enantiomers. The field of enantiomer separation has attracted increased interest in recent years, because of the fact that the biological or pharmacological activity of compounds is restricted in most cases to one of the enantiomers whereby the unwanted enantiomer may exhibit side effects or even toxic effects. The preparation of the capillaries is planned to be performed by packing with chiral stationary phases or by coating with chiral selectors bound to polymers. The synthesis of the chiral stationary phases will be carried out by binding of chiral selectors such as cellulose- and amylose derivatives, crown ethers, proteins and cyclic peptides, chiral metal complexes as well as enantiospecific antibodies to silica gel via suitable silanes. For the preparation of coated capillaries chiral selectors will be bound to polysiloxanes or polymers. The chiral phases will be tested by means of several model compounds and will be subsequently used in screening investigations for the chiral separation of a broad spectrum of drugs classes.