Détermination du mécanisme d’hydrolyse d’un carbamate insecticide: Le Baygon
Written by sctunisie no commentsThe basic hydrolysis of Baygon or o-isopropoxyphenyl-N-methylcarbamate has been studied, in aqueous media, by reversed phase Liquid Chromatography and UV Spectrophotometry. The pseudo-first order rate constant of hydrolysis reaction of Baygon were determined by measurements of the increase UV absorption of o-iso-propoxyphenol versus time, in buffer solutions with pH displayed from 9 to 12. The obtained positive activation enthropy ΔS = + 63,45 J mol-1 K-1, indicates an ElcB hydrolytic mechanism involving unimolecular decomposition of Baygon via a methylisocyanate intermediate.This elimination process is confirmed by the position corresponding to the Baygon point on the Hammett and Brõnsted line, determined by Williams for a serie of substituted N-methyl-carbamates whose decomposition has been established to follow the ElcB mechanism.
N. Ben Hamida, M. Smaali, S. Sabbah
Baygon, kinetic, mecanism, hydrolysis, HPLC, UV Spectrophotometry
Pages 1625-1640
