Synthesis and characterization of a new organic–inorganic Pb 2+ selective composite cation exchanger acrylonitrile stannic(IV) tungstate and its analytical applications

Abstract

A new polymeric–inorganic cation exchanger acrylonitrile stannic(IV) tungstate composite was synthesized by sol–gel technique by incorporating stannic(IV) tungstate precipitate with acrylonitrile. Composite materials formed by the combination of inorganic ion exchangers of multivalent metal acid salts and organic polymers (acrylonitrile, cellulose acetate, polyaniline, polypyrrole, polythiophene, etc.), providing a new class of ‘organic–inorganic’ composite exchangers with better mechanical and granulometric properties, good ion exchange capacity, higher stability, reproducibility and selectivity for heavy metals. The physico-chemical characterization was carried out by elemental analysis, TGA, SEM, XRD, FTIR and TEM studies. Ion exchange capacity, pH titrations, elution and distribution behavior were also carried out to understand the ion exchange behavior of the material. The adsorption behavior of heavy metal ions has been reported in nitric acid and two surfactants media by batch processes. The analytical applications of the material have been explored by achieving some analytically important binary separations from aqueous solution on its columns. The practical applicability of acrylonitrile stannic(IV) tungstate was demonstrated in the quantitative separation of Fe 3+and Zn 2+ contents of a commercially available pharmaceutical sample namely Fefol-Z.