Enantiomeric separation of amino alcohols on protein phases using statistical experimental design - A comparative study

Two LC supports often used for giving enantioselective retention were teste d and compared in the reversed-phase mode using statistical experimental de sign. The two supports contain two different proteins, alpha(1)-acid glycop rotein or cellulase immobilised to silica particles, as the chiral selector s. The two chromatographic columns are commercially available as Chiral-AGP and Chiral-CBH. Twelve closely structurally related amino alcohols were us ed as the testing solutes. For each column three important mobile phase des criptors, that improve the chiral recognition, were chosen as variables and retention and separation factors were used as responses. All the tested so lutes were separated using the two protein based supports. However, the hig hest enantioselectivities, i.e., separation factors higher than 10 were obt ained using the Chiral-CBH column. The solute structure, e.g., distance bet ween the nitrogen atom and the chiral carbon atom, and position as well as type of substituent in the aromatic ring highly influence the enantioselect ivity on both columns. For one of the solutes the choice of mobile phase co mposition could be used to control the retention order of the two enantiome rs. (C) 2000 Elsevier Science B.V. All rights reserved.