Abstract

In the present study, a novel magnetic adsorbent modified with ionic liquid (IL), Fe3O4@SiO2@ dimethyl octadecyl 3-(trimethoxysilyl) propyl ammonium chloride nanoparticles, was synthesized. The prepared magnetic nanoparticles were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermo gravimetric analysis (TGA) and vibrating sample magnetometer (VSM). The supercritical fluid extraction (SFE) was applied for extraction of three pyrethroid residues including fenpropathrin, cyhalothrin, and fenvalerate from fruit and vegetable samples. The extracted analytes were precocentrated by magnetic solid phase extraction (MSPE). The extracted pyrethroid residues were introduced to high performance liquid chromatography -ultra violet (HPLC-UV) for ultra-trace analyses. A Taguchi orthogonal array (OA) experimental design with an OA(16) (4(5)) matrix was employed for optimization the effecting parameters on SFE of the analytes. In addition, the adsorption and desorption conditions in MSPE were optimized by choosing the appropriate parameters. Under the optimal conditions, good linearity at 2.5-250 mu g L-1 (0.9941 <= R-2 <= 0.9998) and 0.3-5 mg kg(-1) (0.9931 <= R-2 <= 0.9994) good precision 3.2-6.5% and 5.1-8.4%, and suitable limits of detection I mu g L-1 and 0.1 mg kg(-1) were obtained for MSPE and SFE-MSPE, respectively. The results showed that the present method is a simple, accurate and high efficient approach for the determination of pyrethroids in the fruit and vegetable samples. (C) 2015 Elsevier B.V. All rights reserved.