Etude analytique par HPLC et spectrophotométrie UV de l'hydrolyse du méthiocarb en milieu aqueux
Written by sctunisie no commentsThis paper deals with the kinetic hydrolysis mechanism of methiocarb or 3,5-dimethy1-4-thiomethylphenyl-N-methylcarbamate in aqueous media. This work is carried out by reversed phase Liquid Chromatography and UV Spectrophotometry. The obtained positive activation entropy ΔS = +32,30 J mole-1K-1, indicates an ElcB hydrolytic mechanism involving unimolecular decomposition of methiocarb via a methylisocyanate intermediate. This elimination process is confirmed by the position of corresponding to the methiocarb point on the Hammett and Brönsted line wich has been determined by Williams for a series of substituted N-methylcarbamate whose decomposition has been established to follow the ElcB mechanism.
N. Ben Hamida, M. Smaali, S. Sabbah
Methiocarb, hydrolysis, mechanism, HPLC, U.V Spectrophotometry
Pages 143-157
