Separation of lanthanides using ion-interaction chromatography with HDEHP coated columns

A rapid and high resolution separation of lanthanides by HPLC technique has been developed using Di-(2-ethylhexyl) phosphoric acid (HDEHP) coated reverse phase column and a-hydroxy isobutyric acid as the complexing reagent for elution. A gradient elution technique has been developed for achieving the separation of the entire lanthanide series. Isocratic elution procedure has also been developed for the separation of lighter (La to Gd) as well heavier lanthanides (Lu to Tb). This paper describes the separation methods developed and their application for the determination of lanthanides in a fission product mixture.