LAUSR

Abstract This study describes the preparation of core–shell magnetic nanoparticles coated with hydrophobic surface-modified silica as the magnetic solid-phase extractor of triclosan. A one-pot eco-friendly route is presented here. The cores (CoFe2O4, γ-Fe2O3 and MnFe2O4) were separately coated by a silica shell, which was then alkylmodified, both reactions in Stober conditions. Characterizations involved FAAS, HRTEM, XRD, VSM, FTIR, contact angle, TGA, BET area, DLS and zeta potential. The hydrophobic nanoparticles presented nearly spherical magnetic cores of ∼13 nm and a silica shell thickness of ∼2 nm. The organofunctionalization was effective. The three hydrophobic nanomaterials adsorbed triclosan. Further experiments used CoFe2O4 based nanomaterial. Analysis of the preconcentrated real sample by HPLC revealed a linear range of 0.4–102.4 μg L−1, good linearity (R2 > 0.99), limit of detection and limit of quantification of 0.36 and 1.20 μg L−1, respectively. The signal enhancement was 4.76. The nanoadsorbent was reused, maintaining its high performance.