Highly selective determination of palladium(II) after preconcentration using Pd(II)-imprinted functionalized silica gel sorbent prepared by a surface imprinting technique

Abstract.

A novel Pd(II)-imprinted amino-functionalized silica gel sorbent was prepared with the help of a surface-imprinting technique for the preconcentration and separation of Pd(II) prior to its determination by inductively coupled plasma atomic emission spectrometry. Compared to the traditional solid sorbents and non-imprinted polymer particles, the ion-imprinted polymers (IIPs) had a higher adsorption capacity and selectivity for Pd(II). The maximum static adsorption capacity of the imprinted and non-imprinted sorbent for Pd(II) was 26.71 mg g⁻¹ and 10.13 mg g⁻¹, respectively. The relative selectivity factor (α_r) of Pd(II)/Zn(II), Pd(II)/Au(III), Pd(II)/Ru(III), Pd(II)/Rh(III), Pd(II)/Pt(IV), Pd(II)/Ir(III), Pd(II)/Fe(III) and Pd(II)/Zn(II) is 39.0, 60.2, 92.0, 85.0, 50.0, 58.0 and 45.0, respectively. The detection limit (3σ) of the method is 0.36 µg L⁻¹. The relative standard deviation was 3.2% for eight replicate determinations of 10 µg of Pd²⁺ in 200 mL water sample. The method was validated by analyzing a standard reference material, and the results obtained were in good agreement with the standard values. The method was also applied to the determination of trace palladium in geological samples with satisfactory results.