Speciation analysis of antimony by highly selective solid-phase extraction of Sb(III) with ion-imprinted polymers

Speciation analysis of antimony by highly selective solid-phase extraction of Sb(III) with ion-imprinted polymers

Poster

Kristina Krasimirova1, Tanya Yordanova1
1Faculty of Chemistry and Pharmacy, Sofia University "Saint Kliment Ohridski", Sofia

Toxicological profile of antimony and bioaccumulative properties of particular Sb species are well known – the inorganic chemical forms are much more harmful than organic species, especially the lower oxidation state Sb(III). In this sense, reliable knowledge about Sb speciation is essential taking into account significant differences between toxicity of trivalent and pentavalent forms. The aim of this work is preparation Sb(III)-imprinted polymers and their further application as adsorbents for non-chromatographic speciation analysis of inorganic antimony in water samples. The imprinted polymers (IPs) were synthesized by radical polymerization of methacrylic acid and trimethylolpropane trimethacrylate in the presence of different chelating ligands (morin, thionalide and pyrrolidine dithiocarbamate). After removal of the template Sb(III), 60–74 % of the ligands remain in polymer matrix (calculated from elemental analysis data) to form recognition sites of the sorbents. Extraction efficiency and selectivity of Sb(III)-IPs were studied by batch method. Acidity of aqueous media, time of sorption, type/concentration of the eluent were investigated in order to define the optimal conditions for selective separation of Sb(III) in presence of Sb(V). Quantitative sorption (>96%) was achieved by all of synthesized IPs at pH 8 for 30 min, while elution was performed with 0.5 M thiocarbamide for at least 30 min. Analytical procedure for determination of Sb(III) in bottled waters based on selective solid-phase extraction with imprinted polymers followed by ICP-OES measurement was developed.
Acknowledgement: The authors gratefully acknowledge the financial support provided by Sofia University Scientific Foundation (Grant 80-10-149).
Keywords: Sb, ion-imprinted polymers, solid-phase extraction, speciation analysis