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How mobile phase composition and column temperature affect enantiomer elution order of liquid crystals on amylose tris(3‐chloro‐5‐methylphenylcarbamate) as chiral selector
Author(s) -
Vaňkátová Petra,
Kubíčková Anna,
Kalíková Květa
Publication year - 2021
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.202000350
Subject(s) - enantiomer , elution , phase (matter) , acetonitrile , chemistry , alkyl , chromatography , analytical chemistry (journal) , chemical engineering , organic chemistry , engineering
Abstract A comprehensive study into the effects of mobile phase composition and column temperature on enantiomer elution order was conducted with a set of chiral rod‐like liquid crystalline materials. The analytes were structurally similar and comprised variances such as length of terminal alkyl chain, presence of chlorine, number of phenyl rings, and type of chiral center. Experiments were carried out in polar organic and reversed‐phase modes using amylose tris(3‐chloro‐5‐methylphenylcarbamate) immobilized on silica gel as the chiral stationary phase. For all liquid crystals, reversal of elution order of enantiomers was observed based on type of used cosolvent and/or its content in the mobile phase; for some of the liquid crystals a temperature‐induced reversal was also observed. Both linear and nonlinear dependencies of natural logarithm of enantioselectivity on temperature were found. Tested mobile phases comprised pure organic solvents and binary and tertiary mixtures of acetonitrile with organic solvents and/or water. Effect of acidic/basic mobile phase additives was also tested. Effect of structure of chiral selector is briefly discussed.