Preparation of Tilmicosin Imprinted Polymers and Its Application to Solid Phase Extraction

Molecularly imprinted polymers (MIPs) with high selectivity to tilmicosin (TIM) were prepared using tylosin (TYL) as dummy template, methacrylic acid(MAA) as monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker. The effects of 4 porogens including dimethyl formamide, methanol, acetone, and chloroform on the recognition capability of MIPs were investigated. Orthogonal test was used to optimize the preparation of MIPs, and the optimal composition was as follows: 1.0 mmol TYL, 8.0 mmol MAA, 20.0 mmol EGDMA, 6.0 mL chloroform, 20.0 mg azobisisobutyronitrile. The solid phase extraction conditions and characteristics of MIN as adsorptive material for the selective extraction and enrichment of TIM were also studied. The recovery of TIM was above 90% when the following procedure was applied to MIN cartridge: conditioning with methanol and water(pH 9.0), loading with acetonitrile, cleaning with methanol and chloroform respectively, and eluting with 3 mL methanol-ammonia(95:5, V/V). The recovery of TIM on non-imprinted polymers cartridge was only 32%.