Magnetic molecularly imprinted polymers are used to selectively extract cephalosporins from milk samples and analyze by LC-MS/MS

Cephalosporins were extracted from milk samples by using magnetic molecularly imprinted polymers (MMIP). To characterize the physical properties of MMIP, an experiment was conducted involving both static and dynamic adsorption. Samples were analyzed with LC-MS/MS to identify cephalosporin residues. The quantitative technique employed was the use of an isotope as an internal standard. Analysis was conducted using an Ascentis C8 column with a mobile phase consisting of a 0.1% aqueous solution of formic acid and acetonitrile. The determination coefficients varied between 0.9945 and 0.9995, as indicated by the linear equations. Cephalosporins exhibited a diverse spectrum of recovery rates, varying between 80.7% and 118.3%, accompanied by a range of relative standard deviations spanning from 3.8% to 13.5%. The detection limits for 9 kinds of cephalosporins in milk samples varied from 1 μg kg−1 to 20 μg kg−1, while the quantification limits ranged from 3 μg kg−1 to 60 μg kg−1. The successful implementation of the validated technique has been applied to detect 9 different kinds of cephalosporins in real milk products.