Nanosized ion-imprinted polymer doped with Alizarin Red S for separation and quantification of zinc(II) prior to its determination by electrothermal AAS

The authors describe a nanostructured zinc(II)imprinted polymer carrying Alizarin Red S as a ligand for separation and preconcentration of ultra-trace levels zinc(II). The adsorbent was obtained by bulk polymerization of a mixture of Zn(II) nitrate, Alizarin Red S, methacrylic acid, ethylene glycol dimethacrylate and 2,2'-azobis(isobutyronitrile). Zn(II) was then removed by treatment with ethanol and 2.0 mM HNO3. The imprinted nanoadsorbent was characterized by FT-IR spectroscopy and scanning electron microscopy. Following sorption of Zn(II) from the sample, it is desorbed with 3.0 M HCl and then quantified via electrothermal atomic absorption spectrometry. Under optimized conditions, the calibration plot is linear in the 3.0 to 250 ng L-1 Zn(II) concentration range, the detection limit is 0.7 ng L-1, and the relative standard deviation is +/- 4.0% (for n = 8). The method was successfully applied to the determination of Zn(II) in (spiked) water samples and hair, and in a certified reference material (MA-1b; reference gold ore) which corroborates the utility of the method.