(+)-(18-Crown-6)-2,3,11,12-tetracarboxylic acid is a chiral crown ether that is generally used in capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). It has been successfully used as a chiral selector in capillary zone electrophoresis for the separation of a variety of optically active amines.
18-Crown-6-Tetracarboxylic acid as a chiral additive for the simultaneous separation of o-, m- and p-enantiomers of phenylalanine family by capillary electrophoresis. 
Comparison of enantiomer separation on two chiral stationary phases derived from (+)-18-crown-6-2,3,11,12-tetracarboxylic acid of the same chiral selector. 
Enantioseparations of primary amino compounds by high-performance liquid chromatography using chiral crown ether-based chiral stationary phase. 
Enantiomeric discrimination of isoxazoline fused β-amino acid derivatives using (18-Crown-6)-2,3,11,12-tetracarboxylic acid as a chiral NMR solvating agent. 
 Z.Chen, et al, Enantiomer, 2001, 6(1), pp 19-25.
 W.Lee, et al, Microchem. J., 2005, 80(2), pp 213-217.