Magnetic solid-phase extraction based on restricted-access molecularly imprinted polymers for ultrarapid determination of ractopamine residues from food samples by capillary electrophoresis.

An ultrafast, efficient, and eco-friendly method combining magnetic solid phase extraction and capillary electrophoresis with diode array detection have been developed to determine ractopamine residues in food samples. A restricted access material based on magnetic and mesoporous molecularly imprinted polymer has been properly synthesized and characterized, demonstrating excellent selectivity and high adsorbent capacity. Short-end injection capillary electrophoresis method was optimized: 75 mM triethylamine pH 7 as BGE, -20 kV, 50 mbar by hydrodynamic injection during 8 s, and capillary temperature at 25 °C; reaching ultrafast ractopamine analysis (∼0.

Magnetic and mesoporous molecularly imprinted polymer synthesized by rational computation design: Sample preparation and analysis of ractopamine.

Through density functional theory calculations was studied theoretically the formation process of a magnetic and mesoporous molecularly imprinted polymer for ractopamine (RAC), evaluating the molecular electrostatic potential map, functional monomers, functional monomer / template stoichiometry and crosslink agents. The results revealed that the best conditions for the synthesis were established with acrylic acid as functional monomer in a 1: 4 stoichiometry using acetonitrile as the solvent and ethylene glycol dimethacrylate as crosslink agent. It was observed that nine hydrogen bonds established between the RAC and acrylic acid play a key role on the pre-polymerization complex.