Preliminary evaluation of Magnetic Nanoparticles for glyphosate contaminated water remediation.

Glyphosate (GLY) is one of the most disputed herbicides due to its extensive use and suspected toxicity. The widespread use across the globe may also lead to excessive accumulation with further contamination of water bodies, exceeding permitted limits. Herein, magnetically guided iron oxide nanoparticles (magnetite/maghemite) coated with polydopamine (PDA) and functionalized with different metal ions (Ti(IV), Cu(II) and Fe(III)), have been preliminary investigated for water refinement from GLY and as a possible solid phase extraction material for future analytical applications. The ideology takes advantages of the chemical properties of glyphosate in order to develop a proper absorption material with magnetic properties, facilitating remediation. Experimentally, the magnetic nanoparticles were firstly obtained using different synthesis method, out of which the most favorable was the co-precipitation. Hence, nanoparticles were coated by selfpolymerized PDA and further functionalized with different metal ions. Different coating time and protocols were tested and evaluated. The characteristic physical and chemical features of particles were evaluated by X-ray diffraction (XRD), FTIR spectroscopy, scanning electron microscopy (SEM), energy Dispersive X-Ray (EDX), transmission electron microscopy (TEM). Magnetic properties were assessed using an in-house test. Chemo-remediation, i.e. the affinity of produced nanoparticles towards glyphosate, was investigated by ion chromatography coupled to high resolution mass spectrometer (IC-HRMS). Experiments, performed in different conditions of GLY concentration, water sample volume and complexity of the matrix, showed promising results, demonstrating the strong adsorption of the analyte by the synthesized materials. Additionally, results suggested that the Ti(IV) functionalized nanoparticles exhibit an higher, specific and selective adsorption of GLY compared to the bare ones and nanoparticles functionalized with other metal ions. The magnetically driven approach is a fast and efficient way for the remediation of GLY contaminated water. These engineered nanoparticles have a huge future prospect in terms of sustainable green analytical chemistry and possible water remediation from other emerging contaminants like organophosphorus pesticides, in addition to as solid phase extraction materials.