Speaker
Description
Abstract:-
Chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate) is one of the harmful pesticide that persist long time in the environment and effect human health. As a result of its accumulation in the environment and the effect it causes on human health its degradation into non-harmful substances is of high importance. In recent days, Plasma assisted degradation that involves highly energetic species such as radicals, ions to induce molecular fragmentation is emerging as an effective method for their removal. In this work, Density Functional Theory (DFT) based calculations were performed to investigate the various degradation pathways of chlorpyrifos. Potential protonation sites were identified through the Natural Bond Orbital (NBO) analysis, charge distribution, electrostatic potential (ESP) mapping and the calculation of proton affinities at various sites. In order to predict the bonds that are most likely to break under plasma conditions, Bond dissociation energies (BDEs) of different bonds have been calculated. Along with the Plasma degradation pathways, Time-Dependent Density Functional Theory (TD-DFT) was also performed to understand the photo-induced electronic transitions and excited-state pathways that facilitate degradation. This theoretical study explains the plasma induced degradation of chlorpyrifos at molecular level, helping to design better ways for the pesticide removal using plasma technologies.
References
[1] E. Taillebois et al. “Molecular features and toxicological properties of four common pesticides, acetamiprid, deltamethrin, chlorpyriphos and fipronil”. Bioorganic & Medicinal Chemistry, 23 (2015) 1540–1550
[2] Quintano, M.M., Rocha, W.R. “Computational insights into the reactivity of chlorpyrifos and chlorpyrifos-methyl toward singlet oxygen”. Journal of Molecular Modeling, 27, 282 (2021).
Acknowledgement
This work was supported by the Slovak Research and Development Agency under the Contract no. APVV-22-0522 and the Slovak Grant Agency for Science (contract no. VEGA 1/0553/22). Funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I01-03-V04-00047. This work was supported in part through the Comenius University in Bratislava CLARA@UNIBA.SK high-performance computing facilities, services and staff expertise of Centre for Information Technology (https://uniba.sk/en/HPC-Clara).
