Étude cinétique de la dégradation hydrolytique d’un insecticide : le Bendiocarb
Written by sctunisie no commentsThis paper deals with the kinetic hydrolysis mecanism of Bendiocarb or 2,2-dimethyl-1,3-benzodioxol-4-yl-Nmethylcarbamate in aqueous media. This work is carried out by reversed phase Liquid Chromatography and UV Spectrophotometry. The determination of 2,2-dimethyl-1,3-benzodioxol-4-ol, as the main product of Bendiocarb hydrolysis gives evidence for the significant reactivity of this insecticide in aqueous media. Temperature effects were determined by measuring the base hydrolysis rate constant for Bendiocarb. The obtained positive entropy + 112 Jmol-1K-1, indicates an E1cB hydrolytic mechanism involving unimolecular decomposition of Bendiocarb via a methylisocyanate intermediate. This elimination process is confirmed by the position of the point corresponding to the Bendiocarb on the Brönsted and Hammett lines wich has been determined by Williams for a serie of substituted N-methylcarbamate whose decomposition has been established to follow the E1cB mechanism.
F. Boujelbane, N. Ben Hamida
Bendiocarb, kinetic, mechanism, HPLC, spectrophotometric UV
pages 121-132
