Extraction of aminobenzoic acid with TOA and TBP

A series of extraction equilibrium experiments for aminobenzoic acid were carried out. Tri-n-octylamine (TOA) and tributyl phosphate (TBP) were selected as complexing agents. 1-Octanol and kerosene were selected as diluents. The effects of extractant concentration and pH on the distribution ratio were discussed in detail. It was found that there are ion-pair association and hydrogen-bond complexing in the extraction. Expressions of the equilibrium distribution for different solvent systems are proposed. The precision of the models is satisfactoy.