Degradation products of chlomethoxynil (X-52) in soil

The degradation of unlabelled and ^l4C-labelled chlomethoxynil (2,4-dichlorophenyl 3′-methoxy-4′-nitrophenyl ether) in a flooded soil was studied in the laboratory, using thin-layer chromatography (TLC) and combined gas chromatography-mass spectrometry (GC-MS).

Chlomethoxynil was rapidly degraded, and labelled chlomethoxynil was largely transformed into substances which were unextractable with organic solvents. Moreover, most of the radioactive substances extracted with organic solvents were not “free” compounds but complexes. The degradation products identified were the amino derivative (2,4-dichlorophenyl 4′-amino-3-methoxyphenyl ether), the demethyl derivative (2,4-dichlorophenyl 3′-hydroxy-4′-nitrophenyl ether), the formylamino derivative (2,4-dichlorophenyl 4-formylamino-3′-methoxyphenyl ether), the acetylamino derivative (2,4-dichlorophenyl 3-methoxy-4′-acetylaminophenyl ether), thepropionylamino derivative (2,4-dichlorophenyl 4-propionylaminophenyl ether), 2,4-dichlorophenol, and several other minor compounds.