betadex and ethyl-lactate

A new mixed gas chromatographic stationary phase composed of 2,3,6-tributyl-beta-cyclodextrin and AgNO3(in polyethylene glycol 400) was synthesized for the first time. It was coated on fused silica capillary column. Excellent selectivity was obtained for the separation of seven enantiomeric pairs and four groups of positional isomers of aromatic compounds. The recognition and separation mechanisms were discussed by measuring enthalpy, entropy, free energy and the difference in enthalpy and entropy of these compounds. Results were compared with those obtained on 2,3,6-tributyl-beta-cyclodextrin stationary phase. The results showed that the mixed stationary phase had positive synergistic effects.

Topics: beta-Cyclodextrins; Chromatography, Gas; Cyclodextrins; Lactates; Propanols; Silver Nitrate; Stereoisomerism