Stability study of Iprodione in alkaline media in the presence of humic acids

- Influence of humic acids on the stability of Iprodione was investigated.
- The catalytic activity of these natural colloidal aggregates in mentioned reaction was studied.
- Inhibitory effects for this pesticide were observed in the presence of these humic substances.
- These behaviors were rationalized in terms of the micellar pseudophase model.

The influence of humic aggregates in water solution upon the chemical stability of Iprodione has been investigated under basic conditions. Taking into account that an important part of soils are colloids, the possibility of its presence implies that soil composition and its structure will play an important role in the stability of this pesticide. A kinetic model was applied to this system and the kinetic coefficients were obtained. An inhibition upon the alkaline hydrolysis of Iprodione (2-fold) was observed and it was rationalized in terms of the micellar pseudophase model. These results have been compared with the corresponding ones in the same natural colloidal aggregates in the presence of other pesticides.