TLC-based enantiomeric separation of amino acids onto β-CD-incorporated glutaraldehyde-crosslinked PVA electrospun fiber stationary phase

Abstract

Simple and economical methods for chiral separations are always needed in synthesis and drug development and as biomarkers, besides many other useful applications. Cyclodextrins (CDs) are chiral host molecules and have been used to separate a number of chiral analytes. In this study, we have successfully prepared electrospun films of β-CD incorporated into polyvinyl alcohol (PVA) through glutaraldehyde (GA) crosslinking. These films of β-CD-PVA-GA electrospun fibers are characterized by Fourier transform infrared (FTIR) and scanning electron microscopy (SEM), which were subsequently used for thin-layer chromatography (TLC)-based enantiomeric separation of histidine and serine pairs. Amino acids were detected by spraying the chromatograms with the ninhydrin solution. Among various solvent systems employed, it was found that the separation of serine enantiomers with a resolution of 1.6 was possible with the mobile phase ethanol–butanol–ethyl acetate–water–acetone (4:5:5:0.5:1.5, v/v), and histidine enantiomers with a resolution of 1.4 were possible with the mobile phase ethanol–butanol–ethyl acetate–water–acetone (4:5:4.5:0.5:1.5, v/v). This proves that the prepared stationary phase is efficient in enatioresolution of selected amino acid pairs and can be further examined for physiological samples.