Selective adsorption of L-TA/D-TA by β-cyclodextrin derivative modified with l-tryptophan: Isotherm, kinetic and thermodynamics studies

b-Cyclodextrin derivative modified with L-tryptophan (L-Trp-CD) was prepared for recognitive chiral separation of tartaric acid enantiomers from ethanol solution. Kinetic properties were successfully investigated by pseudo-first-order model and pseudo-second-order model. Equilibrium data were described by the Langmuir and Freundlich isotherm models. The thermodynamics parameters (positive values of DH8 and DS8, negative values of DG8) indicated that binding system for L-Trp-CD was endothermic, entropy gained and spontaneous. Selective adsorption result of L-tartaric acid (L-TA)/Dtartaric acid (D-TA) by L-Trp-CD indicated that L-Trp-CD has significantly higher adsorption capacity for L-TA compared with D-TA, and the selectivity coefficient is 3.36.