ISSN 1560-0904, Polymer Science, Ser. B, 2009, Vol. 51, Nos. 9–10, pp. 344–351. © Pleiades Publishing, Ltd., 2009.
344
1
INTRODUCTION
Flavonoids, or polyphenolic pigments, are widely
present in plants. Morin (3, 5, 7, 2', 4'-pentahydroxy-
flavone) is a phenolic compound derived by hydroxyl
substitution on the flavone chromophore, this com-
pound being a major component of the plants [1, 2].
The flavone-based compounds, such as morin, are
known to form stable complexes with metal cations,
e.g. iron.
Iron has been known as an essential mineral for our
bodies for over a century, which functions primarily as
a carrier of oxygen in the body, both as a part of hemo-
globin in the blood and of myoglobin in the muscles. It
also aids in immune function, cognitive development,
temperature regulation, energy metabolism, and work
performance. About 90% of the iron in our body is
conserved and reused every day; the rest is excreted. In
order to maintain iron balance in the body, dietary iron
must supply enough iron to meet the 10% gap that our
body has excreted or else deficiency will result.
Groundwater, which is used for drinking, is often
contaminated by organic or inorganic micropollut-
ants; in particular, iron is the typical unwanted constit-
uent in drinking water causing aesthetic problem [3,
4]. One of the possible approaches to extraction of
impurities from groundwater may be a technique of
the molecular imprinting.
1
The text was submitted by the authors in English.
This technique is a specific chemical procedure for
the generation of explicit nano-cavities that can
mimic the behavior (in terms of binding) of naturally
occurring receptor sites [5]. The molecularly
imprinted polymers (MIPs) are generated in the pres-
ence of a template molecule (the analyte of interest).
In non-covalent molecular imprinting (the most com-
mon approach) the template interacts with a func-
tional monomer via hydrogen bonding, electrostatic
or hydrophobic interactions. The pre-polymerization
complex is then incorporated into a polymer network
by a cross-linker. The polymerization process usually
proceeds via a free-radical mechanism resulting in the
production of a rigidly cross-linked polymer matrix
monolith. After that the monolith is crushed and
ground to a suitable size. The template can then be
removed by a mechanism of washing involving a sol-
vent (usually methanol) and an acid or base. Following
the removal of the template, the resultant imprinted
polymer possesses the ability to recognize the template
(or closely related structural analogues) with high
selectivity and specificity [6].
One of the foremost applications of molecular
imprinting is related to a solid phase extraction [7–
13]. In theory, molecular imprinting provides greatly
increased selectivity and sensitivity over conventional
solid phase extraction packing materials. Furthermore
due to the specific nature of the interactions between
rebinding template and chemical functional groups
within the pores or cavities of the cross-linked poly-
mer matrix, it is expected that molecularly imprinted
Imprinted Polymer Particles for Iron Uptake:
Synthesis, Characterization and Analytical Applications
1
Mostafa Khajeh
a
, Massoud Kaykhaii
b
, Hossein Hashemi
b
, and Majid Mirmoghaddam
b
a
Department of Chemistry, University of Zabol, P.O. Box 98615-538, Zabol, Iran
b
Department of Chemistry, Faculty of Sciences, University of Sistan & Balouchestan, Zahedan, Iran
e-mail: m_khajeh@uoz.ac.ir
Received September 1, 2008;
Revised Manuscript Received February 16, 2009
Abstract—This work reports the preparation of molecularly imprinted polymer particles for selective extrac-
tion and determination of iron ions from aqueous media. The polymer particles were synthesized from
Fe(NO
3
)
3
, morin, 4-vinylpyridine, ethyleneglycoldimethacrylate, and 2,2'-azobisisobutyronitrile and char-
acterized by IR and DSC both prior to and after removing the Fe-morin complex by leaching with HCl. The
effect of different parameters, such as pH, adsorption and desorption time, type and minimum amount of
eluent for removing the complex from polymer was evaluated and optimized. The proposed method is char-
acterized by the detection limit of 3.1 μg l
–1
anddynamic linear range of 25 to 200 μg l
–1
, with the relative
standard deviation less than 8.8%. The method was applied to the recovery and determination of iron ions in
a few real samples.
DOI: 10.1134/S1560090409090048
SYNTHESIS