Preparation of a boronic acid functionalized magnetic adsorbent for sensitive analysis of fluoroquinolones in environmental water samples

Abstract

In this work, a new boronic acid functionalized magnetic nanoparticle modified with poly(4-vinylphenylboronic acid-co-divinylbenzene) was synthesized and used as a magnetic solid-phase phase extraction (MSPE) adsorbent for the enrichment of trace fluoroquinolones (FQs) from environmental water samples. The magnetic adsorbent was characterized by scanning electron microscopy, transmission electron microscopy, elemental analysis, and FTIR spectroscopy. To obtain the optimal extraction parameters for FQs, several main extraction conditions were investigated in detail. Under the optimized conditions, a convenient and sensitive method for the determination of trace FQ residues in water samples was established by coupling MSPE with high-performance liquid chromatography with diode array detection. Low detection (S/N = 3) and quantification (S/N = 10) limits were achieved for the targeted analytes, within the ranges of 0.050–0.12 μg L⁻¹ and 0.16–0.41 μg L⁻¹, respectively. In addition, the developed method showed good linearity, acceptable repeatability and precision. Finally, the proposed method was successfully applied for the detection of trace FQ residues in environmental water samples. Satisfactory recoveries obtained for the determination of FQs in spiking samples ranged from 72.0–118%. The results indicate well that the interaction of boron–nitrogen coordination between the adsorbent and analytes plays a key role in the extraction of FQs.