Separation of liquid crystals using non-aqueous capillary electrokinetic chromatography

Liquid crystals are widely used in electronics, medicine and other fields. Analytical separations are important in the development of new liquid crystals to control the purity of synthesized substances. The sample analysis is important for detection of impurities formed during synthesis. Liquid crystal-forming substances cannot be separated by capillary zone electrophoresis due to the absence of readily ionizable groups. Therefore electrokinetic chromatography was used in this work. Another problem complicating the analysis was the very low solubility of analytes in water. Separations in this work were therefore carried out under non-aqueous conditions in acetonitrile with acetic acid to adjust the pH and hexadecyltrimethyl-ammonium chloride as a detergent to mobilize the non-ionized analytes. Under these conditions, it was possible to separate impurities from synthesized analytes in samples.