Ionic liquid-coated magnetic SiO2@Fe3O4 nanocomposite for temperature-assisted solid-phase extraction of venlafaxine

Abstract

A temperature-assisted solid-phase extraction method was developed for the extraction of venlafaxine prior to its spectrofluorimetric determination. Ionic liquid modified Fe3O4 (IL@SiO2@Fe3O4) nanoparticles were prepared, characterized and used as the sorbent. A simple, one-step, rapid and nature-friendly method was used for the preparation of iron oxide nanoparticles using cinnamon extract. The synthesized Fe3O4 was characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The SEM images showed that the synthesized Fe3O4 nanoparticles have an approximately spherical structure with the sizes in the range of 30–60 nm. The synthesized Fe3O4 nanoparticles were coated with three ionic liquids: 1-butyl-3-methylimidazole hexafluorophosphate, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and ethyl-3- methylimidazolium ethyl-1 sulfate. The ionic liquid-coated magnetic nanoparticles were used for the extraction of venlafaxine from aqueous solutions. The highest extraction efficiency was obtained using 1-butyl-3-methylimidazole hexafluorophosphate-coated nanoparticles. The extracted venlafaxine was then determined spectrofluorimetrically at λex and λem of 261 and 301 nm, respectively. Under the optimal conditions, the relation between venlafaxine concentration and fluorescence intensity was linear in the range of 0.003–3.00 mg L−1 of the initial solution. The limit of detection for the determination of venlafaxine was found to be 0.001 mg L−1. The presented method was applied for the determination of venlafaxine in real samples with satisfactory results.