Hybrid nanomaterial based on magnetic multiwalled carbon nanotube-octadecylphosphonic acid modified zirconia for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons from edible oils

Abstract

A novel magnetic solid-phase extraction (MSPE) sorbent, magnetic multiwalled carbon nanotube-octadecylphosphonic acid modified zirconia (mMWCNT–ZrO₂–C18) composite, was fabricated via a simple solvothermal reduction method to extract polycyclic aromatic hydrocarbons (PAHs) from edible oils, coupling with high performance liquid chromatography analysis. The hydrophobic ZrO₂–C18 nanoparticles were introduced to enhance the extraction capability. Factors influencing the extraction efficiency, i.e. the type and volume of desorption solvent, amount of the sorbent, and adsorption and desorption time, were systematically investigated. Under the optimal conditions, calibration curves were linear (R² > 0.9937) over the concentration range from 0.20 to 200 ng g⁻¹. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) achieved were in the range of 0.06–0.55 and 0.20–1.83 ng g⁻¹, respectively. The intra- and inter-day relative standard deviations were less than 7.21%. A comparative study indicated that higher recoveries were obtained by using mMWCNT–ZrO₂–C18 compared to when using bare mMWCNTs. The results indicated that the mMWCNT–ZrO₂–C18 nanomaterial was endowed with great adsorption capability and had significant potential in the preconcentration of PAHs from edible oil samples.