Molecular modeling of DDT's and it's major metabolites adsorption in the interlaminar space of montmorillonite

Abstract

A simple adsorption mechanism of the organochloride insecticide DDT and it's most common metabolites DDD and DDE in the interlaminar layer of montmorillonite mineral is discussed in this paper, based on the results of molecular modeling. A model of a simple fragment of the montmorillonite crystal with the interlaminar layer was created and used. The interlaminar layer contained water as a solvent and the ionic forms of sodium or calcium as exchangeable cations along with the molecules of DDT/DDD/DDE. The molecular interactions were simulated by force fields and the results of the simulation could be explained by the physical characteristics of the models which were studied with bioinformatics tools as well. Based on the observed mechanisms, the adsorption of DDT and it's metabolites in the interlaminar layer of montmorillonite is possible and it is partly responsible for the persistent nature of these insecticides.