Separation of rare earth elements by high performance liquid chromatography using a covalent modified silica gel column

A new modified silica gel material with chemically bound phosphonic acid was tested as lanthanide ions adsorption and their basic characteristics (thermodynamics, stability and physical description) studied. This inorganic chemically active beads (ICABs) are suitable for the solid phase extraction (SPE) and separation of the rare earth elements (REE). The HPLC procedure, using the 10µm diameter ICAB with chemically immobilized phosphonic acid [alpha]-hydroxyisobutyric acid (HIBA) as the eluent and the post-column derivatization using Arsenazo III as the reagent, was worked out and found efficient to perform a good separation of REE.