Separation of erythromycin using aqueous two-phase system based on acetonitrile and carbohydrates

Abstract

In this work, the ability of aqueous two-phase system (ATPS) based on carbohydrates (sorbitol, maltose monohydrate, and fructose) and acetonitrile for separation of erythromycin was investigated. For this purpose, binodal curves and tie-lines for three ATPSs were determined. The LLE data was also successfully correlated with the Othmer-Tobias and the Bancroft equations. The effective excluded volume (EEV) model was used to estimate the soluting-out ability of carbohydrates. Moreover, the partitioning of erythromycin in the ATPS was studied. Furthermore, the effect of carbohydrate and acetonitrile concentrations as well as temperature on the partitioning behavior of erythromycin were examined. In order to estimate the effect of temperature on the partitioning of erythromycin, molar Gibbs energy (ΔGEA), molar entropy (ΔSEA), and molar enthalpy (ΔHEA) were calculated. In all ATPSs the top phase is acetonitrile-rich while the bottom phase is carbohydrate-rich and erythromycin tends to migrate to the top phase. The results show that sorbitol has a higher soluting-out ability than maltose monohydrate and fructose. In addition, it can be concluded that the partitioning process of erythromycin is exothermic and the partition coefficient was decreased with increasing of erythromycin content.