Partitioning of cephalexin in ionic liquid aqueous two-phase system composed of 1-butyl-3-methylimidazolium tetrafluoroborate and ZnSO 4

Ionic liquid aqueous two-phase system (ilatps) was applied in the extraction and separation of hydrosoluble antibiotics. the partitioning behavior of cephalexin (cex) in 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]bf 4)-znso 4 aqueous two-phase system was studied by the partitioning parameter of the extraction efficiency. the effect of the volume of [bmim]bf 4,the concentration of znso 4,temperature,ph,and the volume of znso 4 solution was discussed concretely. when the volume of [bmim]bf 4 was 2 ml and the concentration of znso 4 was 35,the extraction efficiency of cex could reach 92.64 with ph unadjusted. the effect of the volume of [bmim]bf 4 on the extraction efficiency was higher than that of the concentration of znso 4. the temperature influenced not only the formation of aqueous two-phase system but also the extraction efficiency of cex. the target was found to be preferentially extracted to the [bmim]bf 4-rich phase at the ph below 4.3. the partition of cex to the top phase was enhanced by increasing the volume of [bmim]bf 4,the concentration of znso 4,and temperature; however,the partition of cex to the top phase increased by decreasing the ph. © 2013 yan fang li et al.