Chiral separations of basic drugs and organic acids can be achieved using cyclodextrins or cyclodextrin derivatives as chiral selectors in surface-modified capillaries. The influence of temperature and selector concentration on separation performance was investigated in specially modified capillaries. Separations of basic compounds at acidic pH were performed in capillaries modified by either dynamic or permanent coating by adsorption of non-ionic hydroxylic polymers. Separations of acidic compounds could be significantly improved by use of thermally immobilized poly(vinyl alcohol) or adsorbed cationic polymers as surface coatings. The influence of non-ionic and cationic coatings on separations of acidic compounds was compared with regard to resolution, separation efficiency and analysis time.
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