Extraction and Mechanism Investigation of Trace Cefuroxime Axetil Using Ionic Liquid-Salt Aqueous Two-phase System
As an effective extraction method,ionic liquid aqueous two-phase systems(ILATPS) based on 1-butyl-3-methylimidazolium tetrafluoraborate(BF4) and Na2CO3 has been used to extract cefuroxime axetil.Effects of the ionic liquids concentration,Na2CO3 dosage and sort of ionic liquids on the extraction have been investigated.The thermodynamic parameters(ΔG°T,ΔH°T and ΔS°T) were determined.This method was applied to the determination of cefuroxime axetil in real water samples.The results showed that extraction efficiency of cefuroxime axetil was found to increase with increasing Na2CO3 and BF4 at the range of Na2CO3 0.8-2.0 g and BF4 1-2 mL.Compared with Cl/Na2CO3 ILATPS,BF4/Na2CO3 ILATPS has more advantages.The thermodynamic parameters ΔG°T0,ΔH°T0,ΔS°T0 illustrate that hydrophobic interactions were the main driving force in the BF4/Na2CO3 ILATPS of cefuroxime axetil extraction,the extraction process did not occur emulsification.Under the optimum conditions,more than 93% of the cefuroxime axetil in real water could be extracted into the ionic liquid-rich phase in a two-step extraction.