Displacement chromatography of gadolinium isotopes with strong cation exchange resin using 1,2-cyclohexanedinitrilotetraacetic acid (CDTA)

Adsorptive separation of Gd³⁺ ions was evaluated using DOWEX-50×8 ion exchange resin. It has shown a maximum adsorption capacity of 228.50 mg/g at optimum pH 5 and room temperature. Separation of Gd isotopes was investigated using packed bed columns of the resin in displacement chromatographic techniques where 1,2-cyclohexanedinitrilotetraacetic acid was used as displacer in the mobile phase. Isotopic analysis data by using MC-ICP-MS confirmed that the front end of the Gd adsorption band exhibited enrichment of the heavier isotope (¹⁶⁰Gd), while the lighter isotopes (¹⁵⁷Gd and ¹⁵⁵Gd) were concentrated at the rear end of the stationary phase. (author)