Developing a novel magnetic organic polymer for selective extraction and determination of 16 macrolides in water and honey samples

Abstract

A novel magnetic organic polymer Fe₃O₄@SiO₂@Tb-PDAN was designed and synthesized, which was used as an adsorbent for magnetic solid-phase extraction (MSPE) of 16 macrolides (MALs) in water and honey. The synthesized adsorbent was characterized using techniques including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Then several parameters of the extraction process were further optimized. Under the optimized conditions, an MSPE-LC-MS/MS method was established for extraction and determination of 16 MALs, which showed good linearity (r ≥ 0.999), low limits of detection (0.001-0.012 μg L^-1 for water and 0.001-0.367 μg kg^-1 for honey) and satisfactory recoveries (70.02-118.91%) with the relative standard deviations (RSDs) lower than 10.0%. This established method was then successfully applied to detect MALs in real samples, which suggested that Fe₃O₄@SiO₂@Tb-PDAN was a potential magnetic adsorbent for efficient extraction and analysis of MALs.

Fig. 1. Scheme illustration for preparation of Fe₃O₄@SiO₂@Tb–PDAN and the MSPE procedure.

Fig. 2. The SEM image of (a) Fe₃O₄, (b) Fe₃O₄@SiO₂@Tb–PDAN; the TEM image of (c) Fe₃O₄ (d) Fe₃O₄@SiO₂@Tb–PDAN.

Fig. 3. (a) FT-IR spectra of Fe₃O₄, Fe₃O₄@SiO₂ and Fe₃O₄@SiO₂@Tb–PDAN; (b) XRD patterns of Fe₃O₄ and Fe₃O₄@SiO₂@Tb–PDAN; (c)VSM curves of Fe₃O₄ and Fe₃O₄@SiO₂@Tb–PDAN.

Fig. 4. Effect of (a) adsorbent dosage; (b) sample solution pH; (c) salt concentration; (d) extraction time.

Fig. 5. Effect of (a) type of eluent; (b) elution volume; (c) desorption time.