Imprinted covalent organic frameworks prepared by thiol-ene click reaction for selective solid-phase microextraction of aminoglycosides from milk and honey

Abstract

Covalent organic framework molecularly imprinted polymers (CMIPs) was prepared using the thiol-ene click post-synthetic modification. The morphological, chemical characteristics and porosity were systematically characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and N2 adsorption–desorption. Isothermal adsorption, kinetic adsorption, and selective adsorption were used to evaluate the binding property of CMIPs. After being prepared as a solid-phase microextraction (SPME) fiber coating, the CMIPs-SPME pretreatment process for the extraction of six aminoglycosides was established after optimizing parameters such as desorption solvent and time, extraction time, pH value of the sample, and ion concentration. Under the optimized conditions, the CMIPs-SPME was combined with UPLC-MS/MS for the determination of trace aminoglycosides in milk and honey samples. The limits of quantification (S/N = 10) in milk and honey samples were 0.007–0.07 μg kg−1 and 0.04–0.1 μg kg−1, respectively. The relative recoveries at three different spiked levels (1, 10, and 100 μg kg−1) for milk and honey are in the ranges of 86.2 %–115.3 % (RSD ≤ 9.6 %) and 88.1 %–114.3 % (RSD ≤ 10.4 %), respectively. The results indicated that the CMIPs-SPME pretreatment method for the determination of aminoglycosides in real samples is accurate, sensitive, and reliable.