Ion-imprinted beads for molecular recognition based mercury removal from human serum

Int J Biol Macromol. 2007 Jan 30;40(2):159-66. doi: 10.1016/j.ijbiomac.2006.07.002. Epub 2006 Jul 15.

Abstract

The aim of this study is to prepare ion-imprinted polymers which can be used for the selective removal of mercury ions [Hg(2+)] from human serum. N-Methacryloyl-(L)-cysteine (MAC) was chosen as the complexing monomer. In the first step, Hg(2+) was complexed with MAC and the Hg(2+)-imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-(l)-cysteine) (MIP) beads were synthesized by suspension polymerization. After that, the template ions (i.e., Hg(2+)) were removed using thiourea (0.5%, v/v) in 0.05 M HCl. The specific surface area of the MIP beads was found to be 59.04 m(2)/g with a size range of 63-140 micro m in diameter and the swelling ratio was 91.5%. According to the elemental analysis results, the MIP beads contained 87.0 micro mol MAC/g polymer. The maximum adsorption capacity was 0.45 mg Hg(2+)/g beads. The applicability of two kinetic models including pseudo-first order and pseudo-second order model was estimated on the basis of comparative analysis of the corresponding rate parameters, equilibrium capacity and correlation coefficients. Results suggest that chemisorption processes could be the rate-limiting step in the adsorption process. The relative selectivity coefficients of MIP beads for Hg(2+)/Cd(2+), Hg(2+)/Zn(2+) were 14.7 and 21.5 times greater than the non-imprinted (NIP) matrix, respectively. The MIP beads could be used many times without decreasing in their adsorption capacities significantly.

MeSH terms

  • Cations, Divalent / chemistry
  • Cysteine / analogs & derivatives*
  • Cysteine / chemical synthesis
  • Cysteine / chemistry
  • Cysteine / therapeutic use
  • Humans
  • Mercury / blood*
  • Mercury Poisoning / therapy*
  • Methacrylates / chemical synthesis
  • Methacrylates / chemistry*
  • Methacrylates / therapeutic use
  • Microspheres*
  • Particle Size
  • Sorption Detoxification*
  • Spectroscopy, Fourier Transform Infrared
  • Spectrum Analysis, Raman

Substances

  • Cations, Divalent
  • Methacrylates
  • poly(hydroxyethyl methacrylate-N-methacryloylcysteine)
  • Mercury
  • Cysteine