Preparation and Application of MolecularlyImprinted Polymers for FivePyrethroid Insecticides

Abstract

Molecularly imprinted polymers (MIPs) that had high selectivity for five pyrethroid pesticides with high detection and exceedance rates were synthesized through precipitation polymerization using ethyl chrysanthemate and phenyl ether-biphenyl eutectic mixture as double template molecules, acrylamide as a functional monomer, ethylene glycol dimethacrylate as a crosslinking agent, and acetonitrile as a porogen. The imprinted polymers prepared were then characterized and evaluated through scanning electron microscopy (SEM) and an equilibrium adsorption experiment. The results showed that the MIPs had specific adsorption capacities for five pyrethroid pesticides. A solidphase extraction column was prepared using the synthesized polymers as the adsorption material, and a molecularly imprinted solid-phase extraction-gas chromatography equipped with an electron capture detector (MI-SPE-GC-ECD) method was confirmed for the determination of five pyrethroid pesticide residues in agricultural products. A good linear relationship was present between the peak area and the concentration of pyrethroid insecticides within the range of 2-100 μg/kg. The correlation coefficient (R²) was greater than 0.9930, and the minimum limits of detection and quantification were 15.5-25.8 and 54.3-88.1 ng/L, respectively. Under different levels of additives, the standard recovery of pyrethroid pesticides in the samples varied from 72.8% to 110.2%, and the relative standard deviation (RSD) was less than 5.5%. In conclusion, this method enables the rapid separation and efficient enrichment of multiple pyrethroid pesticides in agricultural products in a single step.