Synthesis and application of ion-imprinted polymer particles for solid-phase extraction and determination of trace scandium by ICP-MS in different matrices

Abstract

A novel Sc(III) ion-imprinted polymers (Sc-IIP) sorbent was prepared by using Sc(III) ion-8-hydroxyquinoline complex as the template molecule and methacrylic acid, ethylene glycol dimethacrylate (EGDMA) as the functional monomer and cross-linker, respectively. In the present work, a new method using a microcolumn packed with Sc-IIPs as a solid-phase extraction adsorbent was developed for the selective separation and preconcentration of trace amounts of scandium(III) prior to the determination by inductively coupled plasma mass spectrometry. Various factors influencing the separation and preconcentration of trace scandium, such as pH, sample flow rate and breakthrough volume, elution concentration and volume were investigated in detail. Scandium can be quantitatively retained on the IIPs sorbent at pH 4.0–6.5 from sample volume up to 300 mL and then eluted efficiently with 5 mL 3% HNO₃ solution, therefore an enrichment factor of 60 was accomplished. The maximum adsorption capacity of the ion-imprinted and non-imprinted sorbent was 12.8 mg g⁻¹ and 3.5 mg g⁻¹, respectively. Under optimal conditions, the detection limit for scandium was 0.013 ng L⁻¹ in water, 0.46 ng g⁻¹ in geological sample, and the relative standard deviation was 3.2% (n = 11) at the 0.5 μg L⁻¹. The recoveries of Sc in the spiked environmental water samples ranged from 98.0% to 103% with 100 mL of water sample. The proposed method was validated using certified reference materials and applied to the determination of trace scandium in geological samples and environmental water samples with satisfactory results.