Fe(3)O(4)/polyethylene glycol nanocomposite as a solid-phase microextraction fiber coating for the determination of some volatile organic compounds in water

Abstract

A high-performance metal oxide polymer magnetite/polyethylene glycol nanocomposite was prepared and coated in situ on the surface of the optical fiber by sol-gel technology. The magnetite nanoparticles as nanofillers were synthesized by a coprecipitation method and bonded with polyethylene glycol as a polymer. The chemically bonded coating was evaluated for the headspace solid-phase microextraction of some environmentally important volatile organic compounds from aqueous samples in combination with gas chromatography and mass spectrometry. The prepared fiber was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The mass ratio of nanofiller and polymer on the coating extraction efficiency, morphology, and stability were investigated. The parameters affecting the extraction efficiency, including the extraction time and temperature, the ionic strength, desorption temperature, and time were optimized. The sol-gelized fiber showed excellent chemical stability and longer lifespan. It also exhibited high extraction efficiency compared to the two types of commercial fibers. For volatile organic compounds analysis, the new fiber showed low detection limits (0.008-0.063 ng/L) and wide linearity (0.001-450 × 10⁴ ng/L) under the optimized conditions. The repeatability (interday and intraday) and reproducibility were 4.13-10.08 and 5.98-11.61%, and 7.35-14.79%, respectively (n = 5). For real sample analysis, three types of water samples (ground, surface, and tap water) were studied.

Keywords: magnetite nanoparticles; nanocomposites; polyethylene glycol; sol-gel technology; solid-phase microextraction.