Selective solid phase extraction of propranolol on multiwell membrane filter plates modified with molecularly imprinted polymer.

Molecularly imprinted polymers (MIPs) were synthesized in 24-well glass fiber membrane filter plates to obtain a novel type of solid phase extraction device for the cleanup of propranolol. Sample processing parameters like residence time during sample loading, sample volume, pH, sample solvent, type and amount of washing and elution solvents were investigated and optimized. Important differences from the traditional molecularly imprinted solid phase extraction (MISPE) cartridges have been identified. The MIP modified composite membrane suits well for the sample preparation of low volume biological samples. A protocol has been elaborated for the quantitation of propranolol from urine and plasma samples in the clinically relevant concentration ranges. Preliminary validation results indicate that the composite MIP membrane filter plates offer a viable alternative to existing MISPE cartridges and at the same time have advantages like much easier and faster synthesis method and high-throughput analysis.