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Pesticides masked with cyclodextrins – A survey of soil samples and computer aided evaluation of the inclusion processes.

Domenii publicaţii > Chimie + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: Ferencz L., Balog A.

Editorial: Fresenius Environmental Bulletin, 19 (2), p.172-179, 2010.


During the survey, we measured the contamination levels with a broad variety of pesticides in soil samples collected from Central Romania. Organochlorine, triazine, car-bamate, phenoxy acid and organophosphorus pesticides were analyzed. Among the most detected pollutants, we found pesticides prohibited in the European Union, such as isomers of hexachlorocyclohexane (HCHs) and DDT, together with their metabolites. In step two, we modelled the complexation phenomenon of pesticides with cyclodextrines, with the aim of obtaining new forms which are less side-effected, more stable and more soluble. We followed the variation of the steric energy during the complexation, computing different structural and energetic factors of the interactions using self-developed formula and software. Water molecules negatively affected the inclusion process because guest molecules must extrude them; consequently the formulation process requires higher energy. We computed mathematical correlations between dates referring to stability of the complexes and steric, respectively, hydrophobic parameters. The complexation phenomenon was relatively good for all pesticides. However, we observed partial inclusion as well. Additionally, we made investigations on insects and observed considerable higher acceptance level of pesticides combined with cyclodextrines in comparison with pure pesticides. This was attributed to the changes in the physical properties and taste of the complexes suggesting that they could be applied in lower concentration.

Cuvinte cheie: cyclodextrines, inclusion complexes, molecular modelling, pesticides