Physically Adsorbed Chitosan-Based Coatings for the Electrophoretic Separation of Biologically Active Substances

Coatings for the inner walls of quartz capillaries were obtained using cationic high-molecular-weight chitosan with a degree of deacetylation of 95%. The dependence of the electroosmotic flow velocity on the pH of the background electrolyte was studied and the stability of the coatings under the influence of various solvents was assessed. The results were compared with those for another cationic coating based on poly(diallyldimethylammonium chloride) (PDADMAC). In separating amino acids, catecholamines, and organic acids, the chitosan-based coatings showed slightly lower efficiency compared to PDADMAC coatings, but provided higher resolution for the biologically active analytes studied. Chitosan on the inner walls of the quartz capillary enhanced enantioselectivity in the separation of enantiomers of β-blockers (carvedilol, propranolol, and sotalol) in the presence of (2-hydroxypropyl)-β-cyclodextrin in the background electrolyte, as well as nonsteroidal anti-inflammatory substances (ketoprofen and ketorolac) using vancomycin as a second chiral selector.