A model for the formation and degradation of bound residues of the herbicide 14C-isoproturon in soil.
The humic monomer catechol was reacted with 14C-isoproturon and some of its metabolites, including 14C-4-isopropylaniline, in aqueous solution under a stream of oxygen. Only in the case of 14C-4-isopropylaniline, incorporation in oligomers, in fulvic acid-like polymers, and in humic acid-like polymers was observed. The main oligomer was identified by mass spectrometry as 4,5-bis-(4-isopropylphenylamino)-3,5-cyclohexadiene-1,2-dione. Oligomers and polymers containing bound 14C-4-isopropylaniline were subjected to biodegradation studies in a loamy agricultural soil during 55 days by quantifying 14CO2 evolved. In all cases, significant mineralization rates could be determined, which, however, were much smaller than those of free 14C-4-isoproturon and free 14C-4-isopropylaniline in the same soil.
Reuter
S
S
GSF-Institute of Soil Ecology, Neuherberg, Germany.
Ilim
M
M
Munch
J C
JC
Andreux
F
F
Scheunert
I
I
D001673:Biodegradation, Environmental; D002250:Carbon Radioisotopes; D006540:Herbicides / Q000378:metabolism*; D006812:Humic Substances; D008782:Methylurea Compounds / Q000378:metabolism*; D010573:Pesticide Residues / Q000378:metabolism*; D010671:Phenylurea Compounds; D012989:Soil Pollutants / Q000378:metabolism*
D002250:Carbon Radioisotopes; D006540:Herbicides; D006812:Humic Substances; D008782:Methylurea Compounds; D010573:Pesticide Residues; D010671:Phenylurea Compounds; D012989:Soil Pollutants; C028904:isoproturon