Synthesis of a Novel Magnetic Nanocomposite and its Application to the Efficient Preconcentration and Determination of Malachite Green in Fish Samples Using Response Surface Methodology

Malachite green (MG) has been extensively used as a fungicide and parasiticide in fish farms. At present, the use of MG in aquaculture is forbidden because MG and its metabolite were reported to cause human carcinomatosis and mutagenesis. Owing to its low cost and availability, MG may still be used. Herein, extraction and preconcentration methods were developed for spectrophotometric determination of trace amounts of MG in different samples. The methods are based on the extraction of dye by SiO2 coated magnetic nanoparticles (Fe3O4@SiO2) and chloropropyltriethoxysilane (CPTS) core-shell magnetic nanocomposite (Fe3O4@SiO2-CPTS). The influence of pH, dosage of the adsorbent and contact time on the extraction of the dye was explored by response surface methodology. The calibration curve was linear in the range of 0.01-15.00 mg l-1 with detection limit of 2.0 × 10-4 mg l-1 by Fe3O4@SiO2-CPTS. Extraction and preconcentration, based on the two magnetic nanoparticles, were successfully applied for determination of MG in various water and fish samples.