Selective Solid-Phase Extraction of Sulfonamides from Edible Swine Tissues Using High-Performance Imprinted Polymers

In the present study, sulfamethazine-imprinted polymers have been prepared by bulk polymerization method with a living radical photopolymerization using sulfamethazine (SM2) as the template molecule, methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, and azobisisobutyronitrile (AIBN) as the initiator in the porogenic solvent of acetonitrile. After estimating the recognition properties, the imprinting factor of the polymer reached up to 9.3779. Then, the polymer particles were incorporated into a solid-phase extraction (SPE) column for the selective separation and purification of the sulfonamides (SAs), including sulfadiazine (SD), sulfamerazine (SM1), and SM2, from edible swine tissues. By using the detection method of high-performance liquid chromatography with the optimum SPE conditions, the limits of detection and limits of quantitation were calculated as 0.7–2.3 μg kg−1 and 3.4–4.6 μg kg−1 in the complex samples, respectively. The recovery of SAs ranged from 85.5 to 88.3%. Compared with the commonly used Waters Oasis HLB® column, the proposed selective SM2-MI-SPE column has opened a promising new approach for trace enrichment of the residues. It will facilitate sulfonamide residue analysis in animal tissues.