Chloronicotinyl insecticides degradation by UV-light, singlet oxygen, and solar photo-Fenton reaction. Reaction kinetics and toxicity

DELL'ARCIPRETE, MARIA LAURA; SANTOS JUANES, L.; MÁRTIRE D.; FURLONG J.; ARQUES A.; GONZALEZ M.

Cubatao, San pablo, Brasil

Otro; IX Encuentro Latinoamericano de Fotoquímica y Fotobiologia; 2008

Chlronicotinyl insecticides have a novel mode of action: they act as an agonist of nicotinyl acethylcholine receptor.  They are used worldwide for insect pest management since 1991. Despite their extensive use, only scarce information on the nature of the degradation products and toxicity of neonicotinoid pesticide residues is found in the literature. In order to investigate the degradability of insecticides in natural ecosystems, microbiological and kinetic studies of the insecticides and their degradation products were conducted. For these purposes, the degradation of the insecticides mediated by UV light, singlet oxygen O2 (1Äg), and OH. radicals (generated by the solar induced fenton reaction) was investigated using either steady state or time-resolved experiments. Imidacloprid(IMD), Thiacloprid(THIA) and Acetamiprid(ACT) were chosen as probes because of their chemical structure show a common chloropyridine group and markedly differ on the chemical group responsible for the insecticide toxicity