Imprinted polymer particles for selenium uptake: synthesis, characterization and analytical applications

This work reports the preparation of molecularly imprinted polymer (MIP) particles for selective extraction and determination of selenium ions from aqueous media. Polymerization was achieved in a glass tube containing SeO(2), o-phenylenediamine, 2-vinylpyridine (VP), ethyleneglycoldimethacrylate (EDMA), 2,2'-azobisisobutyronitrile (AIBN). The polymer block obtained was ground and sieved (55-75 microm) and the Se-o-phenylenediamine complex was removed from polymer particles by leaching with 2M of HCl, which leaves a cavity in the polymer particles. The polymer particles both prior to and after leaching have been characterized by IR and thermogravimetric (TG) studies. The effect of different parameters, such as pH, extraction time, type and least amount of eluent for elution of complex from polymer were evaluated. Extraction efficiencies >99% were obtained by elution of the polymers with 15 mL of methanol-acetonitrile mixture (1:2, v/v). The limit of detection of the proposed method followed by hydride generation atomic absorption spectroscopy (HG-AAS) was found to be 3.3 microg L(-1) and a dynamic linear range (DLR) of 10-200 microg L(-1) was obtained. The relative standard deviations (R.S.D.s) at 30.0 microg L(-1) of Se were below than 8.1%. The influence of various cationic interferences on percent recovery of complex was studied. The method was applied to the recovery and determination of selenium in different real samples.