PuSH - Publication Server of Helmholtz Zentrum München

13C/12C and 15N/14N isotope analysis to characterize degradation of atrazine: Evidence from parent and daughter compound values.

Environ. Sci. Technol. 47, 6884-6891 (2013)
DOI PMC
Open Access Green as soon as Postprint is submitted to ZB.
Atrazine (Atz) and its metabolite desethylatrazine (DEA) frequently occur in the environment. Conclusive interpretation of their transformation is often difficult. This study explored evidence from (13)C/(12)C and (15)N/(14)N isotope trends in parent and daughter compounds when Atz was dealkylated by (i) permanganate and (ii) the bacterium Rhodococcus sp. NI86/21. In both transformations, (13)C/(12)C ratios of atrazine increased strongly (εcarbon/permanganate = -4.6 ± 0.6‰ and εcarbon/Rhodoccoccus = -3.8 ± 0.2‰), whereas nitrogen isotope fractionation was small. (13)C/(12)C ratios of DEA showed the following trends. (i) When DEA was formed as the only product (Atz + permanganate), (13)C/(12)C remained constant, close to the initial value of Atz, because the carbon atoms involved in the reaction step are not present in DEA. (ii) When DEA was formed together with desisopropylatrazine (biodegradation of Atz), (13)C/(12)C increased but only within 2‰. (iii) When DEA was further biodegraded, (13)C/(12)C increased by up to 9‰ giving strong testimony of the metabolite's breakdown. Two lines of evidence emerge. (a) Enrichment of (13)C/(12)C in DEA, compared to initial Atz, may contain evidence of further DEA degradation. (b) Dual element ((15)N/(14)N versus (13)C/(12)C) isotope plots for dealkylation of atrazine agree with indirect photodegradation but differ from direct photolysis and biotic hydrolysis. Trends in multielement isotope data of atrazine may, therefore, decipher different degradation pathways.
Altmetric
Additional Metrics?
Edit extra informations Login
Publication type Article: Journal article
Document type Scientific Article
Corresponding Author
Keywords Anaerobic Biodegradation ; Enhanced Degradation ; Stable Carbon ; Fractionation ; Fate ; Soil ; Groundwater ; Mechanisms ; Deethylatrazine ; Mississippi
ISSN (print) / ISBN 0013-936X
e-ISSN 1520-5851
Quellenangaben Volume: 47, Issue: 13, Pages: 6884-6891 Article Number: , Supplement: ,
Publisher ACS
Publishing Place Washington, DC
Non-patent literature Publications
Reviewing status Peer reviewed