Modeling Multiple Chemical Equilibrium in Single-Stage Extraction of Atenolol Enantiomers with Tartrate and Boric Acid as Chiral Selector

Enantioselective liquid–liquid extraction (ELLE) was adopted to separate atenolol (AT) enantiomers, where tartrate and boric acid (BA) were used as the chiral selector. Influence of process variables on extraction efficiency were studied, including type of tartaric acid derivatives, type of the organic solvent, pH of aqueous phase, molality of BA and tartaric acid derivatives, as well as temperature. A theoretical model was developed based on the mechanism research on reactive extraction of AT enantiomers by n-hexyl (L)-tartrate (LT) and BA. Important parameters of this model were determined. By modeling and experiment, the optimal conditions identified involve the LT molality of 0.0796 mol·kg–1, BA molality of 0.1 mol·kg–1, AT molality of 1.592 mmol·kg–1, and pH value of 9.00 at 278 K, where the obtained enantioselectivity (α) is 1.8951 and performance factor (pf) is 0.0608.