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Environmental fate & pathways

Hydrolysis

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Half-life of (2-ethoxy-1-methyl-2-oxoethyl)-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate was 110 days at pH 5, 11 days at pH 7, and 4 hours at pH 9. 

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The disappearance of (2-ethoxy-1-methyl-2-oxoethyl)-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate was measured over a pH range of 4 to 9 at 40 °C. The rate of hydrolysis increased with increasing alkalinity. Without correcting for adsorbed substance, apparent half-lives were 9 h at pH 9, 10 d at pH 7 and 100 d at pH 5. Half-lives were 11 days at pH 4, 5 days at pH 7, and 0.5-1 day at pH 9.1. The hydrolysis product 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid has a half-life of more that 21 d in water.

In a similar study, again, the rate of hydrolysis increased with increasing alkalinity, and followed first order kinetics. There was a reversible adsorption of the substance onto the silanized glass walls of the reaction vessels. With correction for adsorbed substance, half-lives of (2-ethoxy-1-methyl-2-oxoethyl)-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate were 4 h at pH 9, 11 d at pH 7 and 110 d at pH 5. Two degradation products could be identified, and the accumulated transformation product of the two identified substances was 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid.