Octadecylsilane-functionalized magnetic core-shell nanosorbent for efficient extraction of polycyclic aromatic...

For the first time, a new octadecyl silane-based magnetic core-shell adsorbent was synthesized and introduced for the efficient extraction of polycyclic aromatic hydrocarbons from complex exhaust smoke matrices. A dual extraction procedure combining dispersive micro-solid phase extraction (DµSPE) and dispersive liquid-liquid microextraction (DLLME) was developed and optimized using this adsorbent, achieving excellent extraction efficiency under mild experimental conditions. Comprehensive physicochemical characterizations confirmed the successful surface modification, core-shell morphology, and high structural stability of the synthesized material. The proposed method, followed by gas chromatography-flame ionization detection (GC-FID), exhibited low limits of detection (0.87-1.10 µg L⁻¹), wide linear ranges, and high correlation coefficients (r² ≥ 0.9983) of the calibration curves. Enrichment factors ranged from 275 to 490, with extraction recoveries between 55 % and 98 %, while intra- and inter-day precision values were below 5 %. Real exhaust smoke analyses revealed detectable analyte levels in the smoke of diesel samples, while matrix effects were negligible. Overall, the developed core-shell magnetic sorbent-based DµSPE-DLLME system offered a rapid, sensitive, and eco-friendly approach for trace determination of hydrophobic organic hydrocarbons in real-world environmental matrices.