Inactivation of polyalkylphosphates--phosphostigmines - by baseous hydrolysis with hydrogen peroxide as a catalysing agent
Jensen-Holm, J.
Ugeskrift for Laeger 143(48): 3206-3211
1981
ISSN/ISBN: 0041-5782 PMID: 7331024 Document Number: 179410
The rate constants for esters of paraoxon and parathion were determined mathematically, based on a few spectrophotometric determinations of absorption coefficients for p-nitrophenol. The rate constants for paraoxon at pH 13 were > 14-fold higher than parathion. The rate constants for the hydrolysis of the 2 compounds was greatly increased by the presence of H2O2, even at low concentrations of the oxidant. By means of enzymatic investigations, the amount of an active organophosphorus compound, most possibly paraoxon, constituted .apprx. 0.35 mg/g deposit material, which might make a total of > 2000 kg. A chemical inactivation procedure was proposed consisting of treatment with NaOH plus H2O2 followed by the addition of HCl in equivalent amounts which forms NaCl. The amount of the catalyzer H2O2 was spontaneously inactivated at the primary alkaline reaction.