oa Fate of the New Phytosantary, Hydroxypyridone Alkaloids, in the Vadose Zone of the Carbonate Beauce Aquifer (France)

The pollution of water resources by phytosanitary products is a recurrent problem. The research of new pesticides and the understanding of the mechanisms controlling their reactivity, mobility and fate in the vadose zone is essential for assessing the risks of transfer to groundwater. Natural alkaloids with a 4-hydroxy-2-pyridone (4H2P) core offer a wide variety of structures, giving them diverse biological activities (insecticide, fungicide, bactericide, …), and seem to be excellent candidates for new types of phytosanitary products. This study will present the fate (mobitlity, reactivity) of two synthetic alkaloids with 4H2P core through agricultural and limestone soils. Results show that these molecules react mainly with organic matter and smectite, with weak sorption energies. These molecules would be retained in the soil, and remobilized without too much energy, particularly in soils that are low in organic matter. Then they cross the limestone at a slower rate than the water in the vadose zone.