Carbon nanofibers decorated with magnetic nanoparticles as a new sorbent for the magnetic solid phase extraction of selected polycyclic aromatic hydrocarbons from water samples

Abstract

A novel nano-adsorbent, magnetic carbon nanofibers (CNFs–Fe₃O₄), was prepared by impregnating magnetic Fe₃O₄ nanoparticles onto the surfaces of carbon nanofibers based on electrostatic interactions. The resulting nanoparticles were used as an adsorbent for the magnetic solid phase extraction of polycyclic aromatic hydrocarbons from environmental water samples. The experimental parameters affecting the extraction efficiency, including the amount of sorbent, desorption conditions, extraction time and salt concentration, were investigated and optimized. Under the optimal conditions, the detection limits of the method (S/N = 3) were in the range of 0.008–0.03 ng mL⁻¹ and the limits of quantification (S/N = 10) were between 0.025 and 0.08 ng mL⁻¹. The repeatability of the method was assessed through five consecutive extractions of independently prepared compound solutions at concentrations of 0.1, 10, and 100 ng mL⁻¹. The observed repeatability ranged between 3.2% and 11.2%, depending on the considered compounds. The developed method was successfully applied to real water samples while the relative recovery percentages obtained from the spiked water samples at three level concentrations (0.1, 10 and 100 ng mL⁻¹) were from 90.1% to 100.9%.