title: New reversed phase-high performance liquid chromatographic method for selective separation of yttrium from all rare earth elements employing nitrilotriacetate complexes in anion exchange mode.
abstract: Separation of Y from other rare earth elements (REE) is difficult because of similarity of its ionic radius to ionic radii of Tb, Dy and Ho. In the new RP-HPLC system with C18 column, tetra-n-butyl ammonium hydroxide (TBAOH) as an ion interaction reagent (IIR), nitrilotriacetic acid (NTA) as a complexing agent at pH=2.8-3.5, and post column derivatization with Arsenazo III, yttrium is eluted in the region of light REE, between Nd and Sm and is base line separated from Nd and Sm and even from promethium. Simple model employing literature data on complex formation of REE with NTA and based on anion exchange mechanism was developed to foresee the order of elution of individual REE. The model correctly predicted that lanthanides up to Tb will be eluted in the order of increasing Atomic Number (At.No.) but all heavier REE will show smaller retention factors than Tb. Concurrent UV/VIS detection at 658nm and the use of radioactive tracers together with γ-ray spectrometric measurements made possible to establish an unique elution order of elution of REE: La, Ce, Pr, Nd, Pm, Y, Sm, Er, Ho, Tm, Yb, Eu, Lu, Dy+Gd, Tb, Sc. The real place of Y however, in this elution series differs from that predicted by the model (Y between Sm and Eu). The method described in this work enables selective separation of Y from La, Ce, Pr, Nd, Pm, Sm and all heavier REE treated as a group.
authors.affiliation: Laboratory of Nuclear Analytical Methods, Institute of Nuclear Chemistry and Technology, 03-195 Warszawa, Poland. Electronic address: r.dybczynski@ichtj.waw.pl.
authors.forename: Rajmund S
authors.initials: RS
authors.lastname: Dybczyński
authors.affiliation: Laboratory of Nuclear Analytical Methods, Institute of Nuclear Chemistry and Technology, 03-195 Warszawa, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Kulisa
authors.affiliation: Laboratory of Nuclear Analytical Methods, Institute of Nuclear Chemistry and Technology, 03-195 Warszawa, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Pyszynska
authors.affiliation: Laboratory of Nuclear Analytical Methods, Institute of Nuclear Chemistry and Technology, 03-195 Warszawa, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Bojanowska-Czajka
mesh_terms: D000838:Anions / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D056831:Coordination Complexes / Q000737:chemistry* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D028581:Lanthanoid Series Elements / Q000737:chemistry / Q000302:isolation & purification; D008674:Metals, Rare Earth / Q000737:chemistry*; D009571:Nitrilotriacetic Acid / Q000737:chemistry*; D015019:Yttrium / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000838:Anions; D056831:Coordination Complexes; D028581:Lanthanoid Series Elements; D008674:Metals, Rare Earth; D015019:Yttrium; D009571:Nitrilotriacetic Acid
keywords: Anion exchange; Nitrilotriacetic acid (NTA); RP-HPLC; Rare earth elements (REE); Yttrium