Selective extraction and column separation for 16 kinds of rare earth element ions by using N, N-dioctyl diglycolacid grafted silica gel particles as the stationary phase

J Chromatogr A. 2020 Sep 13:1627:461393. doi: 10.1016/j.chroma.2020.461393. Epub 2020 Jul 6.

Abstract

The selective extraction and column separation rear earth elements (REEs) were investigated in the present work. Herein, the functional ligand of N, N-dioctyldiglycolic acid (DODGA) was synthesized and chemically grafted on the silica gel (SG) particles to give the novel material SG@DODGA. The obtained SG@DODGA was fully characterized by NMR, BET (Brunauer-Emmett-Teller) N2 physisorption analysis, atom force microscopy (AFM), scanning electronic microscopy (SEM), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). After investigating the adsorption capability of the SG@DODGA towards 16 kinds of REEs (La, Ce, Pr, Nd, Sm, Eu, Gd, Td, Dy, Ho, Er, Tm, Yb, Lu, Y and Sc), the results showed that the adsorption kinetic data was better fitted with pseudo-second-order model and Elovich model, the adsorption isotherms data was suitable for Freundlich model. The above result also indicated that the adsorption mechanism between the SG@DODGA and REEs was chemical ion exchange. Moreover, choose SG@DODGA as the column chromatography stationary phase and packed in a glass column for the column studies to obtain breakthroughs profile of each REEs. Furthermore, the column was used to try to separate the mixed 16 kinds of REEs. The first attempt to preliminary separate REEs result showed that this column could be applied for simply separating REEs. The light REEs La, Ce, Pr, Nd exhibited better separation effect than the other REEs.

Keywords: Column chromatography; DODGA; REEs; Silica gel.

MeSH terms

  • Adsorption
  • Glycolates / chemistry*
  • Hydrogen-Ion Concentration
  • Ions
  • Kinetics
  • Ligands
  • Metals, Rare Earth / isolation & purification*
  • Nitrogen / chemistry
  • Photoelectron Spectroscopy
  • Silica Gel / chemistry*
  • Spectroscopy, Fourier Transform Infrared
  • Temperature
  • Thermogravimetry

Substances

  • Glycolates
  • Ions
  • Ligands
  • Metals, Rare Earth
  • Silica Gel
  • Nitrogen