Étude par HPLC et spectrophotométrie UV de la dégradation hydrolytique d’un insecticide, le Zectran
Written by sctunisie no commentsThis paper deals with the kinetic hydrolysis mecanism of Zectran or 3,5-diméthyl-4-dimethylaminophényl-N-methylcarbamate in aqueous media. This work is carried out by reversed phase Liquid Chromatography and UV Spectrophotometry. The determination of 3,5-diméthyl-4-diméthylamino-phénol, as the main product of Zectran hydrolysis gives evidence for the significant reactivity of this insecticide in aqueous media. The obtained positive activation entropy ΔS = +7,05 J mol-1 K-1 and the absence of basic general catalysis indicate an E1cB mechanism involving unimolecular collapse of the Zectran via a methylisocyanate intermediate. This elimination process is confirmed by the position of the point corresponding to the Zectran on the Brönsted and Hammett lines, determined for a serie of substituted N-methylcarbamate which the decomposition mechanism in aqueous media procede via E1cB.
F. Boujelbane, N. Ben Hamida
Zectran, kinetic, mechanism, HPLC, spectrophotometric UV
Pages 39-51
