Bifunctional monomer magnetic imprinted nanomaterials for selective separation of tetracyclines directly from milk samples.

Novel magnetic molecularly imprinted nanomaterials (DA + BSA-MMIPs) were prepared adopting bovine serum albumin (BSA) and dopamine as bifunctional monomers for the first time. Besides the role of assistant functional monomer, BSA can exclude the proteins with like charges and promote low molecular weight tetracyclines to be adsorbed. Thus, the DA + BSA-MMIPs could fulfil the selective separation of tetracyclines directly from milk samples. The characteristics, polymerization conditions, and adsorption performances of the resultant nanomaterials were investigated in detail. In addition of uniform imprinting layers, stable crystalline phase, and good magnetism of the DA + BSA-MMIPs, they have rapid binding kinetic, high adsorption capacity, and favorable reusability. The imprinted nanomaterials were coupled with HPLC to selectively extract and determine trace tetracyclines from untreated milk samples. The recoveries of tetracyclines are in the range of 84.1-95.8% with relative standard deviations of less than 6.7%. The developed method is especially suitable for the selective enrichment and detection of target compounds directly from a complex sample with proteins.