Preparation and characterization of imprinted microspheres for clopyralid

In this work, the molecularly imprinted polymers (MIPs) and non-imprinted polymers (NIPs) for clopyralid (3,6-DCP) were successfully synthesized via precipitation polymerization using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker and a mixture of butanone (MEK) and n-heptane as porogen under the existence of azobisisobutyronitrile (AIBN). The morphologies, particle sizes, structures, adsorption properties and selective recognitions of polymers were investigated systematically. The average particle sizes of MIP3 and NIP3 were 2.76 μm and 2.15 μm. The apparent maximum binding amount (Qmax) of MIP3 and NIP3 were 67.50 mg·g−1 and 65.02 mg·g−1 in Scatchard analysis. Langmuir isotherm displayed that the Langmuir constant (Kl) of MIP3 and NIP3 were 0.015 L·mg−1 and 0.0065 L·mg−1, the saturation adsorption capacity (Qmax) of MIP3 and NIP3 were 63.23 mg·g−1 and 58.17 mg·g−1. Lagergren pseudo-second-order kinetic plot described that the adsorption process of MIP3 was visualized as chemical absorption. Selectivity analysis revealed that MIP3 possessed highly specific recognition for 3,6-DCP.