Nanopowder synthesis of novel Sn(II)-imprinted poly(dimethyl vinylphosphonate) by ultrasound-assisted technique: Adsorption and pre-concentration of Sn(II) from aqueous media and real samples.

In this research, a novel Sn(II)-imprinted poly(dimethyl vinylphosphonate) nanopowder (Sn(II)-IPDMVPN) was prepared using Sn2+ , dimethyl vinylphosphonate, azobis isobutyronitril and ethylene glycol dimethacrylate as the template, ligand, initiator and cross linker, respectively. The non-imprinted poly(dimethyl vinylphosphonate) nanopowder (NIPDMVPN) was also synthesized utilizing the same procedure without using SnCl2 ·2H2 O in order to compare the results with the Sn(II)-IPDMVPN. The structure, morphology and composition of the products were characterized by XRD, SEM, EDX, XRF, BET, FT-IR and NMR techniques. Some experimental conditions including pH, eluent concentration and sample volume were optimized to maximize Sn(II) adsorption by the Sn(II)-IPDMVPN. It was found that the optimum conditions are pH = 5, 1.00 M of HNO3 as eluent and sample volume up to 50 mL. The results obtained by ICP-MS indicated that the Sn(II)-IPDMVPN had much higher adsorption capacity for Sn(II) ions (about threefold) than the NIPDMVPN. The applicability of the Sn(II)-IPDMVPN was also investigated in three different real samples. Under the best experimental conditions, the calibration graphs were linear in the range of 0.19-90 μg L-1 with a coefficient of determination (R2 ) of 0.990. The detection limit was calculated to be 0.06 μg L-1 . The relative standard deviation (RSD) for six replicate measurements of Sn(II) at 1.00 ng mL-1 was determined to be 1.8%. The results showed that the Sn(II)-IPDMVPN-ICP-MS is a very simple, rapid, sensitive and efficient method for the determination of Sn(II) ions in water samples.