**1.1 Chemistry of glyphosate**

Glyphosate (N-(phosphonomethyl) glycine) is a non-selective post-emergence herbicide widely used in field crops, vegetable crops, and orchards. Glyphosate is absorbed by plants via leaves and shoots and is transported throughout the whole plant. Its usual formulation is salt of a deprotonated acid of glyphosate and a cation, e.g. isopropylamine or trimethylsulfonium. Its chemical structure has three groups (amine, carboxylate, and phosphonate) that form strong coordination bonds with metal ions to form bidentate and tridentate complexes (**Figure 1**). Hence it is a strong chelating herbicide [1].

Chemically, glyphosate is a phosphonate. It is mainly the phosphonate group via which glyphosate is bonded to iron and aluminum oxides by ligand exchange with the formation of mononuclear, monodentate, and/or binuclear, bidentate surface complexes [2].
