Cadmium removal out of human plasma using ion-imprinted beads in a magnetic column

The aim of this study is to utilize ion-imprinted magnetic beads in the selective removal of Cd2+ ions out of human plasma overdosed with Cd2+ ions. The Cd (2+) imprinted magnetic poly(HEMA-MAC) (mPHEMAC-Cd2+) beads were produced by suspension polymerization in the presence of magnetite Fe3O4 in a nano-powder form. The template Cd2+ ions could be reversibly detached from the matrix to form mPHEMAC-Cd2+ beads using 0.1 M thiourea solution. The specific surface area of the mPHEMAC-Cd2+ beads was found to be 24.7 m(2)/g. The MAC and Fe3O4 contents of the mPHEMAC-Cd2+ beads were found to be 41.8 mu mol/g polymer and 8.2% on the average. The Cd2+ adsorption capacity of mPHEMAC-Cd2+ columns decreased drastically from 48.8 mu mol/g to 20.0 mu mol/g as the flow rate is increased from 0.50 ml/min to 3.0 ml/min. The maximum adsorption capacity of the mPHEMAC-Cd2+ beads was determined to be 48.8 mu mol Cd2+/g on the average. The relative selectivity coefficients of the mPHEMAC beads for Cd2+/Pb2+ and Cd2+/Zn2+ were 22.6 and 160.7 times greater than those of the non-imprinted magnetic PHEMAC (mPHEMAC) beads, respectively. The mPHEMAC-Cd2+ beads are reusable for many times with no significant decrease in their adsorption capacities. (C) 2008 Elsevier B.V. All rights reserved.