A novel approach for the direct determination of residual template molecules in molecularly imprinted polymer matrices

Abstract

With inductively coupled plasma optical emission spectroscopy (ICP-OES), this article introduces an analysis method enabling the direct quantitative determination of residual template molecules in molecularly imprinted polymer (MIP) matrices. ICP-OES was applied for the determination of residual iodine in MIPs prepared against the iodinated X-ray contrast agent iohexol. Prior to analysis, a microwave-assisted acidic oxidative digestion method was developed simultaneously enabling the digestion of the polymer matrix and the exhaustive oxidation of organically bound iodine. Excellent recovery rates and a high accuracy confirm the feasibility and utility of a microwave-assisted digestion with subsequent ICP-OES analysis for the determination of residual iodine in MIPs, and indicate the potential of this combination as a widely applicable monitoring tool for the efficiency of template extraction from MIP matrices.