Preparation of Magnetite Nanocomposites based on Azolla Filiculoides fern with Environmental Applications for Organic Pollutants

Azolla Filiculoides fern was utilized as a natural adsorbent to develop a magnetic solid phase extraction method for the preconcentration and determination of trace amounts of chlorpyrifos pesticide, which is a primary environmental concern. In this study, the magnetic solid phase extraction (MSPE) method using magnetite-modified azolla nanocomposites (azolla@Fe۳O۴ NCs) was developed to preconcentrate trace amounts of chlorpyrifos pesticide prior to UV-Vis spectroscopy. The structural characteristics of the synthesized nanocomposites (NCs) were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometry (VSM) methods. In the proposed MSPE method, after optimizing the adsorption/desorption variables in MSPE and obtaining the optimum level of each variable (adsorption step: Vsample = ۵۰ mL, contact time = ۱۵ min, solution pH = ۳, adsorbent mass = ۰.۰۵ g, ionic strength = ۰.۰۱ mol L-۱; desorption step: eluent type and volume = ethanol (۲ mL) for ۱۰ min), the desorbed ethanolic solution was spectrophotometrically investigated in the UV-Vis region. The results confirm the developed MSPE method can be used for the preconcentration and determination of trace amounts of chlorpyrifos in the aqueous samples.