Characterization and quality assessment of binding properties of the monocrotophos molecularly imprinted microspheres prepared by precipitation polymerization in toluene

obtain the desired specific adsorbents for monocrotophos (MCP) to enrichment, separation, and analysis of trace pesticides residue in soils and foods, molecularly imprinted polymer microspheres were prepared by precipitation polymerization using MCP, methacylic acid (MAA), ethylene glycol dimethacrylate, azobisiso- butyronitrile, and toluene as template, functional monomer, crosslinker, initiator, and porogen, respectively. Computer simulation was employed to demonstrate the mechanism of the interaction between MCP and MAA in toluene. It was found that one MCP was entrapped by two MAAs in toluene through hydrogen bond. The binding properties of MCP in toluene for imprinted microspheres were evaluated by equilibrium rebinding experiments. Scatchard plot analysis revealed that there were two classes of binding sites populated in the imprinted polymer microspheres with dissociation constants of 0.0019 and 0.12 mmol/L, respectively. The specificity of the imprinted microspheres was investigated by binding analysis using MCP and structurally related organophosphorous pesticides. The results indicated that the obtained imprinted microspheres showed a good selectivity for MCR