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in Wiley Online Library (wileyonlinelibrary.com).The enantioselective extraction of hydrophobic oxybutynin (OBN) enantiomers by hydrophilic b-cyclodextrin (b-CD) derivatives was studied. The efficiency of extraction depends strongly on a number of process variables such as types of organic solvents and b-CD derivatives, concentration of selector, pH, and temperature. The experimental data were described by a reactive extraction model with a homogeneous aqueous phase reaction of R,S-OBN with b-CD. Important parameters of this model were determined experimentally. The physical distribution coefficients for molecular and ionic OBN were 4.96 Â 10 À3 and 9.52, respectively. The equilibrium constants of the complexation reactions were 1770 and 1340 L/mol for S-and R-OBN, respectively. By modeling and experiment, an optimal extraction condition with pH of 5 and HP-b-CD concentration of 0.1 mol/L was obtained with enantioselectivity (a) of 1.26, which was close to the theoretical maximum of 1.32 and performance factor (pf i ) of 0.036. The model was verified experimentally with excellent results.

This article reports a new chiral separation method-biphasic recognition chiral extraction for the separation of mandelic acid enantiomers. Distribution behavior of mandelic acid enantiomers was studied in the extraction system with

The increasing demand for optically pure compounds stimulates the development of new chiral separation processes on an industrial scale. The enantioselective liquid–liquid extraction (ELLE) of phenylsuccinic acid (PSA) enantiomers using hydrophilic hydroxyphenyl‐β‐CD as extractant (C) was studied experimentally in a countercurrent cascade of 10 centrifugal contactor separators at 293 K. Based on a single‐stage equilibrium model and the law of conservation of mass, a multistage equilibrium model of ELLE was developed to investigate the influence of changes in the process parameterssuch as phase ratios and concentrations on extraction efficiency. The multistage equilibrium model was verified experimentally with a good agreement. The model was applied to predict the symmetrical separation of PSA enantiomers. By modeling, optimal process parameters for the symmetrical separation of PSA enantiomers can beachieved. The minimum number of stages was determined at 22 and 24 for eeeq>98% and eeeq>99%, respectively. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2594–2602, 2013

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