Preparation of a Magnetic Nanoporous Polymer for the Fast and Efficient Extraction of 5-Nitroimidazoles in Milk

• DOI: 10.1021/acs.jafc.9b03127
• Publication Date: 2019-09-19T18:00:16Z
• Authors: Qianqian Wang; Chun Wang; Qiuhua Wu; Zhi Wang
• Keywords: Polymers; Food Contamination; 01 natural sciences; 0104 chemical sciences; Magnetics; Nanopores; Milk; Limit of Detection; Nitroimidazoles; Animals; Cattle; Adsorption; Porosity; Chromatography, High Pressure Liquid

A magnetic nanoporous organic polymer (M-NOP) was prepared as a new adsorbent with excellent extraction capacity and rapid adsorption kinetics for 5-nitroimidazoles (5-NDZs). Hence, a rapid and effective method was proposed for determination of 5-NDZs in milk by combining M-NOP-based magnetic solid-phase extraction with high-performance liquid chromatography. Main extraction conditions were investigated. Under optimal conditions, good linear response was achieved in a range of 2.4-100 ng mL-1 with a lower detection limit of 0.8-1.0 ng mL-1. High accuracy with a recovery of 80.0-116.0% for the fortified samples, good repeatability with relative standard deviation below 10%, and a high enrichment factor of 97-111 were obtained. The rapid adsorption of 5-NDZs on M-NOP is mainly driven by H-bonding, π-stacking, and polar interactions. Finally, the M-NOP-based method was successfully used to determine 5-NDZs in milk samples. The M-NOP is expected to present promising application in the extraction and quantitative analysis of other compounds.