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Hydrolysis and photolysis of flumioxazin in aqueous buffer solutions
Author(s) -
Kwon JeongWook,
Armbrust Kevin L,
Grey Timothy L
Publication year - 2004
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.897
Subject(s) - hydrolysis , degradation (telecommunications) , photodissociation , chemistry , aqueous solution , buffer solution , chromatography , nuclear chemistry , photochemistry , organic chemistry , telecommunications , computer science
To determine the degradation rates and degradation products of the herbicide flumioxazin in aqueous buffer solutions (pH 5, 7 and 9), its hydrolysis and photolysis were investigated at 30 °C in the dark, and in a growth chamber fitted with fluorescent lamps simulating the UV output of sunlight. The rate of hydrolysis of flumioxazin was accelerated by increasing pH. The t 1/2 values at pH 5, 7 and 9 were 16.4, 9.1 and 0.25 h, respectively. Two degradation products were detected and their structural assignments were made on the basis of LC‐MS data. Degradation product I was detected in all buffer solutions while degradation product II was detected in acidic buffer only. Both degradation products appeared to be stable to further hydrolysis. After correcting for the effects of hydrolysis, the photolytic degradation rate also increased as a function of pH and was approximately 10 times higher at pH 7 than that at pH 5, showing t 1/2 values of 4.9 and 41.5 h, respectively. Degradation products formed by photolysis were the same as those formed by hydrolysis. Flumioxazin was degraded more extensively at high pH and should degrade in surface water. Copyright © 2004 Society of Chemical Industry