Preparation and application of a molecularly imprinted polymer for the determination of trace metolcarb in food matrices by high performance liquid chromatography

In this article, for the first time, a molecularly imprinted polymer (MIP) for the metolcarb was prepared by bulk polymerization using metolcarb as the template, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linker. The prepared polymer was characterized by FT-IR, static and kinetic adsorption experiments, and the results showed that it has been successfully synthesized and had good selective ability for metolcarb. The MIP was applied as a sorbent in molecularly imprinted SPE coupled with HPLC-UV for separation and determination of trace metolcarb in three kinds of food matrices at three concentration levels. Under the optimal conditions, the LODs (S/N = 3) of cabbage, cucumber and pear were 7.622, 6.455 and 13.52 mu g/kg, respectively, and recoveries were in the range of 68.80-101.31% with RSD (n = 3) below 3.78% in all cases. To demonstrate further the selectivity of the MIP obtained, a comparison with commercially available C-18 SPE was performed. The results indicated that molecularly imprinted SPE showed better chromatography, better selectivity and higher recoveries for metolcarb than commercially available C-18 SPE.