Adsorption of diazinon and fenitrothion on nanocrystalline magnesium oxides

Nanocrystalline magnesium oxide was prepared by the sol-gel method from magnesium methoxide and characterized by Fourier transform infrared spectroscopy, thermal analysis, X-ray powder diffraction and transmission electron microscopy. Sol-gel derived nanocrystalline magnesium oxide along with a commercial nanocrystalline magnesium oxide was used as adsorbents to study the adsorption of two common, organophosphorous pesticides, diethoxy-[(2-isopropyl-6-methyl-4-pyrimidinyl)oxy]-thioxophosphorane (diazinon) and dimethoxy-(3-methyl-4-nitrophenoxy)-thioxophosphorane (fenitrothion). Adsorption of diazinon and fenitrothion on the sol-gel derived, and commercial nanocrystalline magnesium oxides was studied using UV-vis, FT-IR and 31P NMR spectroscopies. The effect of hydroxyl groups on edge/corner and flat panel of magnesium oxide in adsorption of diazinon and fenitrothion was investigated. The results showed that the adsorption of diazinon on the sol-gel derived nanocrystalline magnesium oxide is destructive whereas on commercial one is non-destructive. Commercial nanocrystalline magnesium oxide showed higher activity in the adsorption of fenitrothion than the sol-gel derived, and adsorptions on both nanocrystalline magnesium oxides are destructive.