TY - JOUR
T1 - Microbial degradation pathways of the herbicide dichlobenil in soils with different history of dichlobenil-exposure
AU - Holtze, Maria S.
AU - Hansen, Hans Christian B.
AU - Juhler, René K.
AU - Sørensen, Jan
AU - Aamand, Jens
N1 - Funding Information:
This work was supported by the Immunalyse Project (Grant no. 9901188, the Danish Technical Research Council), the RECETO Research School and the PESTICON Project (Grant no. 274-05-0399, The Danish Research Council). The skilful technical assistance of Spire Maja Kiersgaard is gratefully acknowledged.
PY - 2007/7
Y1 - 2007/7
N2 - 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.
AB - 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.
KW - 2,6-dichlorobenzamide
KW - Degradation pathway
KW - Dichlobenil
KW - Microbial degradation
KW - Ortho-chlorobenzamide
UR - http://www.scopus.com/inward/record.url?scp=34247880306&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2006.10.028
DO - 10.1016/j.envpol.2006.10.028
M3 - Article
SN - 0269-7491
VL - 148
SP - 343
EP - 351
JO - Environmental Pollution
JF - Environmental Pollution
IS - 1
ER -