RESUMEN
Using cyproheptadine ( CYP) as template molecule, methacrylic acid ( MAA) as monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker, molecularly imprinted polymers (MIP) with high selectivity to cyproheptadine (CYP) were prepared by the optimization of porogen, monomer, and the mole ratio of monomer to template. The specific surface area of the prepared polymers was 24. 9 m2 / g. The recovery of CYP was above 94. 0% when the following procedure was applied to the cartridge of MIP as adsorptive material: conditioning with methanol and water, loading with water, washing with water and methanol, and eluting with methanol-ammonia (95: 5, V/ V). As a control, the recovery of CYP on non-imprinted polymers cartridge (NISPE) was only 38. 9% . The binding capacity of the molecularly imprinted solid phase extraction (MISPE) towards CYP found to be about 8. 8 mg of CYP/ g polymers and the imprinting factor (IF) was about 2. 32. Under optimal conditions, a mixed standard solution of CYP, amitriptyline, sulfadiazine and trimethoprim (10 mg / L each) was uploaded on the MISPE and NISPE for selectivity experiment. The gradient elution was used by using 0. 05% sodium pentanesulfonate solution (A)-acetintrile (B) as a mobile phase. The recoveries on the MISPE for sulfadiazine and trimethoprim (different structure with CYP) were less than 10% , however, the recovery for the similar structural amitriptyline was more than 70% , and the recovery more than 90% for CYP. All the recoveries on the NISPE for four analytes were less than 30% . This new MISPE cartridge was applied to extract and enrich CYP in livestock drinking water sample, and the recoveries of CYP ranged from 80. 5% -97. 7% , and the limit of detection (LOD) was 0. 01 mg / L.