Reyhaneh Kouchakinejad - Department of Chemistry, Tabriz Branch, Islamic Azad University, Tabriz, Iran
Shahab Shariati - Department of Chemistry, Rasht Branch, Islamic Azad University, Rasht, Iran
Jafar Abolhasani - Department of Chemistry, Tabriz Branch, Islamic Azad University, Tabriz, Iran
Ebrahim Ghorbani-Kalhor - Department of Chemistry, Tabriz Branch, Islamic Azad University, Tabriz, Iran
Mohammad Taghi Vardini - Department of Chemistry, Tabriz Branch, Islamic Azad University, Tabriz, Iran

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.

Azolla filiculoides, Magnetic Solid phase Extraction, nanocomposite, Pesticide, Chlorpyrifos