Novel Fe(III)-imprinted beads were prepared by molecular imprinting technique for selective solid-phase extraction
(SPE) of Fe(III) ions prior to its determination by flame atomic absorption spectrometry (FAAS). The functional metalcomplexing
monomer and crosslinking monomer used were methacrylamidoantipyrine (MAAP) and ethyleneglycol
dimethacrylate (EGDMA), respectively. MAAP was synthesized using methacryloylchloride, 4-aminoantipyrine and
pyridine. Fe(III) ions were complexed with MAAP and the Fe(III)-imprinted poly(MAAP-EGDMA) beads were synthesized
by suspension polymerization. After that, the template ions (i.e., Fe(III) ions) were removed using 4.0 M HNO3
solution. The specific surface area of the Fe(III)-imprinted and non-imprinted poly(MAAP-EGDMA) beads was found
to be 1181.45 m2/g and 437.94 m2/g, respectively. The swelling ratio was 60% and 47% for imprinted and non-imprinted
beads, respectively. According to the elemental analysis results, the beads contained 119.0 μmol MAAP/g polymer.
The maximum adsorption capacity, optimum pH and equilibrium binding time were 29.32 mg/g, 4.0 and 80 min, respectively.
Selectivity coefficients for Al(III), Cu(II), Zn(II) and Co(II) ions were compared with Fe(III) ion. Fe(III)-imprinted
beads showed the following order of metal ion affinity: Fe(III)>Zn(II)>Cu(II)>Co(II)>Al(III). The Fe(III)-imprinted
poly(MAAP-EGDMA) beads could be used many times without decreasing their adsorption capacities significantly.