Journal article
Microbial degradation pathways of the herbicide dichlobenil in soils with different history of dichlobenil-exposure
Department of Natural Sciences, Soil and Environmental Chemistry, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, Frederiksberg C, Denmark. msh@geus.dk1
This is the first detailed study of metabolite production during degradation of the herbicide 2,6-dichlorobenzonitrile (dichlobenil). Degradation of dichlobenil and three potential metabolites: 2,6-dichlorobenzamide (BAM), 2,6-dichlorobenzoic acid (2,6-DCBA) and ortho-chlorobenzamide (OBAM) was studied in soils either previously exposed or not exposed to dichlobenil using a newly developed HPLC method.
Dichlobenil was degraded in all four soils; BAM and 2,6-DCBA were only degraded in soils previously exposed to dichlobenil (100% within 35-56 days and 85-100% in 56 days, respectively), and OBAM in all four soils (25-33% removal in 48 days). BAM produced from dichlobenil was either hydrolyzed to 2,6-DCBA or dechlorinated to OBAM, which was further hydrolyzed to ortho-chlorobenzoic acid.
BAM was rapidly mineralized in previously exposed soils only. All potential metabolites and the finding that BAM was a dead-end metabolite of dichlobenil in soils not previously exposed to dichlobenil needs to be included in risk assessments of the use of dichlobenil.
Language: | English |
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Year: | 2007 |
Pages: | 343-351 |
ISSN: | 18736424 and 02697491 |
Types: | Journal article |
DOI: | 10.1016/j.envpol.2006.10.028 |
ORCIDs: | Hansen, Hans Christian B and Sørensen, Jan |