Synergistic extraction of lanthanoids with heterocyclic β-ketoenols and 2,4,6-tri(2-pyridyl)-1,3,5-triazine, TPTZ: Part II. Extraction of La(III), Eu(III) and Lu(III) with a bis(4-acyl-5-hydroxypyrazole) and TPTZ

The synergistic solvent extraction of three trivalent rare earth ions Ln(III) (Ln: La, Eu, Lu), from 0.1 M nitrate medium with 1,12-bis(1′-phenyl-3′-methyl-5′-hydroxy-4′-pyrazolyl)-dodecane-1, 12-dione, HL-10-LH and 2,4,6-tri(2-pyridyl)-1,3,5-triazine, TPTZ, in chloroform, has been studied. Various types of extracted species were highlighted. For lanthanum and europium, two complexes were co-extracted: for high extraction values, the major extracted species were Ln(L-10-L)(L-10-LH)TPTZ; however, for low extraction values, La(L-10-LH)2TPTZ,NO3 and Eu(L-10-L)TPTZ,NO3 were extracted. For lutetium, evidence was given of the extraction of a single species Lu(L-10-L)TPTZ,NO3 in the whole range of extraction values. While the efficiency order of extraction with HL-10-LH was La < Eu < Lu, that of synergistic extraction with HL-10-LH and TPTZ was La < Lu < Eu: this order was controlled by the synergistic donor agent TPTZ.