Preparation of ion-imprinted polyvinyl sulfonate-grafted silica particles for trace enrichment of Th(IV) prior to determination by inductively coupled plasma-mass spectrometry

Abstract

Grafting from polymerisation technique has been used to prepare Th(IV) ion-imprinted polyvinyl sulfonate (IIPVS)-bonded silica particles. The graft polymerisation of vinyl sulfonate (VS) on the surface of silica particles was achieved in aqueous medium through thermal decomposition of surface-bound azo initiators (60°C) in the presence of thorium ion. The prepared material was characterised by Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. The entrapped template ion was then removed using 2 M HCl. The experimental batch rebinding data were successfully described by the Langmuir-Freundlich model. The prepared material was then packed to a PTFE micro-column (20 mm × 3.0 mm, id) to evaluate its efficiency in column operations prior to determination by inductively coupled plasma-mass spectrometry (ICP-MS). The limit of detection of the method and breakthrough capacity of the column was evaluated as 0.074 µg L −1 and 0.83 mg g −1 , respectively. The selectivity of the prepared polymer towards Th (IV) ion was investigated in the presence of some foreign competitor ions, including U(VI). Finally, the proposed method has been used to determine Th(IV) ion in real samples. ARTICLE HISTORY

Synthesis and characterization of a new ion-imprinted polymer for the selective separation of thorium(iv) ions at high acidity

“…7 Recently, this problem began to attract attention in the eld of ion-imprinting technology. Fasihi et al 24 used vinyl sulfonate, a strong ion-exchanger functional ligand, to prepare Th 4+ -IIP, which could start to extract Th 4+ with an extraction efficiency of 41% at pH ¼ 1.6. By far, none of these Th 4+ -IIPs could be used at pH < 1.…”

Selective separation and preconcentration of Th(iv) using organo-functionalized, hierarchically porous silica monoliths

“…6 These materials exhibit a remarkably high specific surface area allowing for high contact efficiency and enhanced mass transfer kinetics between the two hydrophilic phases (sorbent and analyte), as well as easily functionalizable surface properties through postsynthetic grafting [23][24][25][26][27][28][29][30][31][32] or ion-imprinting technique. [33][34][35] In general, mesoporous materials are suitable as stationary phases in chromatographic applications, as the nano-size pores can significantly enhance the extraction efficiency and reduce the analysis time. However, the use of small size particles as packing materials is often associated with a high backpressure of the column, thus reducing mass transport kinetics and limiting their industrial applicability, especially in high flowrate chromatography analysis.…”