Partitioning Behavior of Penicillin G in Aqueous Two Phase System Formed by Ionic Liquids and Phosphate

Abstract

An aqueous two‐phase system (ATPS) was presented with hydrophilic ionic liquid 1‐butyl‐3‐methylimidazolium chloride (Bmim]Cl) and NaH₂PO₄ aqueous solution in this paper. The partitioning behavior of penicillin G in the ATPS was investigated. Concentrations of NaH₂PO₄, penicillin G, and Bmim]Cl were evaluated to determine their effects on the partition coefficient and extraction yield of penicillin G. It was found that both of partition coefficient and extraction yield strongly depended on the concentration of Bmim]Cl, penicillin and NaH₂PO₄. A high extraction yield of 93% was achieved with the following parameters: NaH₂PO₄ · 2H₂O 40% (wt%), penicillin 45000～50000 u/ml, Bmim]Cl 20～21% (wt%). The Bmim]Cl/NaH₂PO₄ system was also applied in a real filtration of penicillin G fermentation broth and the extraction yield was averaged at 91.5%. It is worthy noting that the working pH value of ATPS was at the range of 5～6, no emulsification and protein denaturation could be observed.