Molecularly Imprinted Layer-Coated Silica Gel Particles for Selective Solid-Phase Extraction of Pefloxacin and Enrofloxacin from Milk Samples

Abstract

This study describes the synthesis of a molecularly imprinted polymer (MIP) as a novel solid-phase extraction adsorbent. The MIP consisted of pefloxacin (PEF) as a template, methacrylic acid (MAA) as a functional monomer, and silica gel particles as a support. The MIP was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and static adsorption. The MIP allowed the selective extraction of the fluoroquinolones PEF and enrofloxacin (ENR) and the simultaneous elimination of interfering components from milk matrices. Good linearity was obtained in a range of 2.5–500 ng mL−1, with correlation coefficients (R2) >0.999. The average recovery rates of PEF and ENR ranged from 92.04 to 98.31 %, and the detection limits were 0.8–1.5 ng mL−1. This work provides a sensitive and selective tool for the detection of PEF and ENR residues in milk and potentially in other foods.