HPLC ENANTIOMERIC SEPARATION OF AROMATIC AMINES USING CROWN ETHER TETRACARBOXYLIC ACID

Abstract

Separation of an aromatic amine is presented using Chirosil RCA(+), which consists of a chemically bonded crown ether tetracarboxylic acid stationary phase. To separate this amine, we used as mobile phase aqueous-organic mobile phases consisting of 0.1% HClO₄ in water and acetonitrile or methanol. Plots of ln k′ vs. the volume fraction of the organic modifier showed a non-linear behavior which prompted us to investigate non-chromatographic techniques. In particular, we pursued vibrational circular dichroism in order to elucidate the interactions between the chiral amine and the crown ether tetracarboxylic acid. The enantiomeric separation of several other aromatic amino alcohols molecules was also performed. The relationship between the retention, enantioselectivity and the structure of the molecules is discussed.

Keywords:

• aromatic amine
• chiral separation
• crown ether tetracarboxylic acid
• vibrational circular dichroism (VCD)