Core‐shell magnetic porous organic polymer for magnetic solid‐phase extraction of fluoroquinolone antibiotics in honey samples followed by high‐performance liquid chromatography with fluorescence detection

Abstract

By monomer‐mediated in‐situ growth synthesis strategy, with hydroquinone and 1,3,5‐tris(4‐aminophenyl)benzene as monomers, a core‐shell magnetic porous organic polymer was synthesized through a simple azo reaction. Based on this, a magnetic solid‐phase extraction–high‐performance liquid chromatography–fluorescence detection method was proposed for the analysis of fluoroquinolones in a honey sample. With ofloxacin, ciprofloxacin, enrofloxacin, lomefloxacin, and difloxacin as target analytes, factors affecting the extraction efficiency had been optimized. The LODs were 1.5–5.4 ng/L (corresponding to 0.23–0.81 μg/kg in honey). The linear range was 0.005–20 μg/L for difloxacin, 0.01–20 μg/L for ofloxacin, ciprofloxacin and lomefloxacin, and 0.02–20 μg/L for enrofloxacin. The enrichment factor was 84.4–91.7‐fold with a high extraction efficiency of 84.4–91.7%. The method was assessed by the analysis of target fluoroquinolones in honey samples, and the recoveries for the spiked samples were 79.3–95.8%. The results indicated that the established magnetic solid‐phase extraction–high‐performance liquid chromatography–fluorescence detection method is efficient for the analysis of trace fluoroquinolones in honey.

Amino functionalized magnetic covalent organic framework for magnetic solid‐phase extraction of sulfonylurea herbicides in environmental samples from tobacco land

“…Compared with liquid-liquid extraction, SPE has many advantages, such as easy operation, less consumption of organic solvents, and abundant adsorbents. Magnetic SPE (MSPE), as a new sample pretreatment technique derived from SPE, can achieve phase separation with short analysis time and high enrichment factors (EFs) [21][22][23][24]. Magnetic materials are the key that affects the performance of MSPE.…”

Sodium hexametaphosphate-treated halloysite based solid-phase extraction of biguanides from dietary supplements

“…This phenomenon could be explained based on the ion exchange mechanism and partitioning mechanism. 24,25 As the ionic strength of the elution solvent increased, the electrostatic affinity between negatively charged halloysite and positively charged biguanides would be weakened, leading to an increase in the recovery. In addition, the ion-enriched water layer at the surface of the halloysite would cause a salting-out effect repelling the biguanides toward the methanol-rich elution solvent, which is beneficial for elution.…”

“…This phenomenon could be explained based on the ion exchange mechanism and partitioning mechanism. 24,25 As the ionic strength of the elution solvent increased, the electrostatic affinity between negatively charged halloysite and positively charged biguanides would be weakened, leading to an increase in the recovery. In addition, the ion-enriched water…”

Fabrication of magnetic covalent organic framework for efficient extraction and determination of phthalate esters in milk samples

“…Several COFs have been recently prepared as adsorbents for target organic pollutants [17]. In comparison with the pure COFs, magnetizing COFs can effectively improve the dispersibility, which is favorable for effective contact with the analytes, and overcome the shortcoming of difficult separation from matrix solution [18]. At present, construction and preparation methods of the reported COFs still require a long reaction time, high temperature, and toxic solvents.…”