Abstract: Molecularly imprinted polymer microspheres (MIPMs) were prepared by precipitation polymerization with atrazine as the template molecule, methacrylic acid (MAA) as the functional monomer, and acetonitrile as the porogen. The preparation process was optimized, and the best adsorption performance was observed for MIPMs prepared under the following conditions: atrazine-to-MAA molar ratio 1:4, addition of 50 mL of acetonitrile, and polymerization temperature 60 ℃. The adsorption properties of the MIPMs toward target compounds were investigated through adsorption experiments and Scatchard analysis. It was found that there were two types of adsorption sites for atrazine in the MIPMs, and the maximum apparent binding capacity was 282.69 μmol/g. A molecularly imprinted solid phase extraction (MISPE) column was prepared with the MIPMs as a sorbent for sample pretreatment, and an atrazine-MISPE-high performance liquid chromatography (HPLC) method was established for determining residues of four triazine pesticides, simazine, ametryn, atrazine and prometryn, in foods. The results showed that the MISPE column had specific selectivity to the four triazine pesticides with linear correlation coefficients of 0.999 1–0.999 7. The detection limits of the method were 0.5–5 ng/mL. The average recoveries were between 86.2% and 95.7%, and the relative standard deviations (RSDs) were 1.98%–4.51% (n = 5). This method can easily, accurately and selectively detect triazine herbicide residues in foods.

Key words: atrazine, triazine herbicide residues, molecularly imprinted polymer microspheres, adsorption properties, precipitation polymerization, solid phase extraction, high performance liquid chromatography, food detection