Liquid–liquid extraction of Nd(III) and Eu(III) using nalidixic acid in dichloromethane

The extraction of Nd(III) and Eu(III) as representatives of rare earth elements with 0.1 mol dm −3 nalidixic acid (HNA) in dichloromethane was studied from aqueous solutions of pH 1–8. The quantitative extraction of these metals was observed at pH 6.5. Various parameters affecting their extraction were optimized. The composition of the extracted adduct was determined by slope analysis method that came out to be [(M(NA) 2 ) + (CH 3 COO) − ] where M represents Nd(III) or Eu(III). The effect of various anions and cations on the extraction of these metal ions was also studied. Among the anions, sulfate and phosphate interfered significantly, whereas Fe(III), Cu(II) and Al(III) reduced the extraction.