Separation and preconcentration of La³⁺, Ce³⁺ and Y³⁺ using calix[4]resorcinarene impregnated on polymeric support

Abstract.

A procedure is proposed for separation and preconcentration of lanthanium, cerium and yttrium using octacarboxymethyl-C-methylcalix [4]resorcinarene impregnated onto a polymeric matrix, Amberlite XAD-16. The optimization process was carried out using 2³ factorial design and three variables (pH, concentration of metal ion, sorption flow rate) were regarded as factors. For Ce³⁺ extraction, the variance analysis revealed that pH and concentration of Ce³⁺ was statistically significant. However, for La³⁺ and Y³⁺ pH was significant only. The precision of the method (%RSD) was 2.27 for La³⁺, 1.97 for Ce³⁺ and 2.01 for Y³⁺ at 1 µg mL⁻¹ for ten replicate analyses. The preconcentration factors of La³⁺, Ce³⁺ and Y³⁺ were 125, 83 and 100 respectively. The robustness of this procedure is demonstrated by the recovery achieved for determination of La³⁺, Ce³⁺ and Y³⁺ in the presence of several cations. The procedure was satisfactorily applied to the separation of La³⁺, Ce³⁺ and Y³⁺ from each other and also from common actinides such as UO₂ ²⁺ and Th⁴⁺ by sequential acidic elution system.