Preparation of Monolithic Fibers in Fused Silica Capillary Molds for Molecularly Imprinted Solid-Phase Microextraction

In the last three decades, the use of molecularly imprinted polymers (MIPs) in sample preparation has continuously increased due to the high selectivity that they provide to this critical step. Of particular interest is the combination of molecular imprinting polymers and solid-phase microextraction (SPME) that allows the development of rapid and environmental friendly analytical methods, with high sensitivity and selectivity. The protocol herein presented describes a very simple strategy for the direct preparation of monolithic MIPs using silica capillaries as molds by the copolymerization of methacrylic acid and ethylene glycol dimethacrylate in the presence of propazine as template. The main factors affecting the polymer synthesis (e.g., porogen, monomer, cross-linker, polymerization mixture proportions, polymerization time, and fiber thickness) are described in detail. The proposed strategy is easy to perform in any laboratory without special equipment and allows precise control of the fiber thickness, overcoming this very common drawback in MIP-based fiber preparation.