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| Titel |
Accelerated degradation of 14C-atrazine in an atrazine adapted field soil from Belgium |
| VerfasserIn |
Georg Hamacher, Nicolai David Jablonowski, Rosane Martinazzo, Cesare Accinelli, Stephan Köppchen, Ulrike Langen, Andreas Linden, Martina Krause, Peter Burauel |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250035181
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| Zusammenfassung |
| Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] is one of the most widely
used herbicides in the world. Atrazine is considered to be mobile in soil and has often been
characterized as a rather recalcitrant compound in the environment.
In the present study the accelerated atrazine degradation in an agriculturally used soil was
examined. Soil samples were collected from a Belgian field which was used for
corn-plantations and was regularly treated with atrazine during the last 30 years. The
experiment was conducted under controlled laboratory conditions (GLP) using 14C-labelled
and unlabelled atrazine in accordance to the reported field application dose of 1 mg
kg-1.
Triplicates of treated subsamples were incubated at 50% WHCmax and under
slurry conditions (1:4 soil:solution ratio, using distilled water) in the dark at 20Ë
C.
Control samples were collected at an adjacent pear orchard where no atrazine or other
triazine pesticides application was reported.
After 92 days of incubation, the mineralized amount of atrazine reached 83% of
the initially applied 14C-activity in the atrazine treated soil for the slurry setup. A
maximum of atrazine mineralization was observed in the treated field soil between
6 and 7 days of incubation for both, 50% WHCmax and slurry setups. The total
14C-atrazine mineralization was equally high for 50% WHCmax in the atrazine
treated soil. After an extended lag-phase in comparison to the treated soil the overall
mineralization of 14C-atrazine of 81% was observed in the atrazine untreated soil under
slurry conditions. This observation might be due to a possible cross adaption of the
microflora. These results could be attributed to an atrazine drift during application
since the control samples were taken in an adjacent pear orchard with no atrazine
application history. These results demonstrate an adaption of the microflora to mineralize
atrazine rapidly. The formation of desorbable metabolites as well as the formation of
unextractable, bound atrazine residues during the incubation process was monitored by
accelerated solvent extraction, LC-MSMS and LSC analysis, subsequent to sample
oxidation.
Analysis of the atzABC and trzN genes that code for enzymes able to rapidly
catabolize atrazine are under investigation. This outcome will give evidence of the
global presence of an atrazine adapted soil microflora in atrazine treated field soils. |
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