1
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Masbou J, Payraudeau S, Guyot B, Imfeld G. Dimethomorph degradation in vineyards examined by isomeric and isotopic fractionation. CHEMOSPHERE 2023; 313:137341. [PMID: 36423721 DOI: 10.1016/j.chemosphere.2022.137341] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/15/2022] [Accepted: 11/19/2022] [Indexed: 06/16/2023]
Abstract
Knowledge of the degradation extent and pathways of fungicides in the environment is scarce. Fungicides may have isomers with distinct fungal-control efficiency, toxicity and fate in the environment, requiring specific approaches to follow up the degradation of individual isomers. Here we examined the degradation of the widely used fungicide dimethomorph (DIM) in a vineyard catchment using ratios of carbon stable isotopes (δ13C) and E/Z isomer fractionation (IF(Z)). In a microcosm laboratory experiment, DIM degradation half-life in soil was 20 ± 3 days, and was associated with significant isomeric (ΔIF(Z) = +30%) and isotopic (Δδ13C up to 7‰) fractionation. This corresponds to an isomer enrichment factor of εIR = -54 ± 6%, suggesting isomer selectivity and similar carbon stable isotopic fractionation values of εDIM-(Z) = -1.6 ± 0.2‰ and εDIM-(E) = -1.5 ± 0.2‰. Isomeric and isotopic fractionation values were used to estimate DIM degradation in topsoil and transport in a vineyard catchment over two wine-growing seasons. DIM concentrations following DIM application were up to 3 μg g-1 in topsoil and 29 μg L-1 in runoff water at the catchment outlet. Accordingly, the IF(Z) and δ13C values of DIM in soil were similar to those observed in DIM commercial formulations. The gradual enrichments in DIM-(Z) and 13C of the residual DIM in soil indicated DIM biodegradation over time. DIM biodegradation estimated based on E/Z isomer and carbon stable isotope ratios in topsoil and runoff water ranged from 0% after DIM application up to 100% at the end of the wine-growing season. DIM biodegradation was overestimated compared to conventional approaches relying on DIM mass balance, field concentrations and half-lives. Altogether, our study highlights the usefulness of combining carbon stable isotopes, E/Z isomers and classical approaches to estimate fungicide degradation at the catchment scale, and uncovers difficulties in using laboratory-derived values in field studies.
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Affiliation(s)
- Jérémy Masbou
- Université de Strasbourg, CNRS, ENGEES, ITES UMR7063, F-67084, Strasbourg, France
| | - Sylvain Payraudeau
- Université de Strasbourg, CNRS, ENGEES, ITES UMR7063, F-67084, Strasbourg, France
| | - Benoit Guyot
- Université de Strasbourg, CNRS, ENGEES, ITES UMR7063, F-67084, Strasbourg, France
| | - Gwenaël Imfeld
- Université de Strasbourg, CNRS, ENGEES, ITES UMR7063, F-67084, Strasbourg, France.
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2
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Blessing M, Baran N. A review on environmental isotope analysis of aquatic micropollutants: Recent advances, pitfalls and perspectives. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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3
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Exploring the enantiomeric 13C position-specific isotope fractionation: challenges and anisotropic NMR-based analytical strategy. Anal Bioanal Chem 2021; 413:6379-6392. [PMID: 34498104 DOI: 10.1007/s00216-021-03599-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/27/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
Trying to answer the intriguing and fundamental question related to chiral induction/amplification at the origin of homochirality in Nature: "Is there a relationship between enantiomeric and isotopic fractionation of carbon 13 in chiral molecules?" is a difficult but stimulating challenge. Although isotropic 13C-PSIA NMR is a promising tool for the determination of (13C/12C) ratios capable of providing key 13C isotopic data for understanding the reaction mechanisms of biological processes or artificial transformations, this method does not provide access to any enantiomeric 13C isotopic data unless mirror-image isomers are first physically separated. Interestingly, 13C spectral enantiodiscriminations can be potentially performed in situ in the presence of enantiopure entities as chiral-europium complexes or chiral liquid crystals (CLCs). In this work, we explored for the first time the capabilities of the anisotropic 13C-{1H} NMR using PBLG-based lyotropic CLCs as enantiodiscriminating media in the context of the enantiomeric position-specific 13C isotope fractionation (EPSIF), within the requested precision of the order of the permil. As enantiomeric NMR signals are discriminated on the basis of a difference of 13C residual chemical shift anisotropy (13C-RCSA) prior to being deconvoluted, analysis of enantiomeric mixtures becomes possible. The analytical potential of this approach when using poly-γ-benzyl-L-glutamate (PBLG) is presented, and the preliminary quantitative results on small model chiral molecules obtained at 17.5 T with a cryogenic NMR probe are reported and discussed. A promising analytical approach based on anisotropic irm-13C-NMR spectrometry to potentially reveal the natural 13C/12C isotopic enantiofractionation effects in organic chiral molecules is proposed and discussed.
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4
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Cui G, Lartey-Young G, Chen C, Ma L. Photodegradation of pesticides using compound-specific isotope analysis (CSIA): a review. RSC Adv 2021; 11:25122-25140. [PMID: 35478915 PMCID: PMC9037106 DOI: 10.1039/d1ra01658j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 07/14/2021] [Indexed: 12/20/2022] Open
Abstract
Pesticides are commonly applied in agriculture to protect crops from pests, weeds, and harmful pathogens. However, chronic, low-level exposure to pesticides can be toxic to humans. Photochemical degradation of pesticides in water, soil, and other environmental media can alter their environmental fate and toxicity. Compound-specific isotope analysis (CSIA) is an advanced diagnostic tool to quantify the degradation of organic pollutants and provide insight into reaction mechanisms without the need to identify transformation products. CSIA allows for the direct quantification of organic degradation, including pesticides. This review summarizes the recent developments observed in photodegradation studies on different categories of pesticides using CSIA technology. Only seven pesticides have been studied using photodegradation, and these studies have mostly occurred in the last five years. Knowledge gaps in the current literature, as well as potential approaches for CSIA technology for pesticide monitoring, are discussed in this review. Furthermore, the CSIA analytical method is challenged by chemical element types, the accuracy of instrument analysis, reaction conditions, and the stability of degradation products. Finally, future research applications and the operability of this method are also discussed.
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Affiliation(s)
- Guolu Cui
- School of Environmental Science and Engineering, Tongji University 1239 Siping Road Shanghai 200092 China
- Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092 China
| | - George Lartey-Young
- School of Environmental Science and Engineering, Tongji University 1239 Siping Road Shanghai 200092 China
- Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092 China
| | - Chong Chen
- School of Environmental Science and Engineering, Tongji University 1239 Siping Road Shanghai 200092 China
- Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092 China
| | - Limin Ma
- School of Environmental Science and Engineering, Tongji University 1239 Siping Road Shanghai 200092 China
- Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092 China
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Melsbach A, Ponsin V, Torrentó C, Lihl C, Hofstetter TB, Hunkeler D, Elsner M. 13C- and 15N-Isotope Analysis of Desphenylchloridazon by Liquid Chromatography-Isotope-Ratio Mass Spectrometry and Derivatization Gas Chromatography-Isotope-Ratio Mass Spectrometry. Anal Chem 2019; 91:3412-3420. [PMID: 30672693 DOI: 10.1021/acs.analchem.8b04906] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The widespread application of herbicides impacts surface water and groundwater. Metabolites (e.g., desphenylchloridazon from chloridazon) may be persistent and even more polar than the parent herbicide, which increases the risk of groundwater contamination. When parent herbicides are still applied, metabolites are constantly formed and may also be degraded. Evaluating their degradation on the basis of concentration measurements is, therefore, difficult. This study presents compound-specific stable-isotope analysis (CSIA) of nitrogen- and carbon-isotope ratios at natural abundances as an alternative analytical approach to track the origin, formation, and degradation of desphenylchloridazon (DPC), the major degradation product of the herbicide chloridazon. Methods were developed and validated for carbon- and nitrogen-isotope analysis (δ13C and δ15N) of DPC by liquid chromatography-isotope-ratio mass spectrometry (LC-IRMS) and derivatization gas chromatography-IRMS (GC-IRMS), respectively. Injecting standards directly onto an Atlantis LC-column resulted in reproducible δ13C-isotope analysis (standard deviation <0.5‰) by LC-IRMS with a limit of precise analysis of 996 ng of DPC on-column. Accurate and reproducible δ15N analysis with a standard deviation of <0.4‰ was achieved by GC-IRMS after derivatization of >100 ng of DPC with 160-fold excess of (trimethylsilyl)diazomethane. Application of the method to environmental-seepage water indicated that newly formed DPC could be distinguished from "old" DPC by the different isotopic signatures of the two DPC sources.
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Affiliation(s)
- Aileen Melsbach
- Helmholtz Zentrum München , Institute of Groundwater Ecology , 85764 Neuherberg , Germany
| | - Violaine Ponsin
- Centre for Hydrogeology and Geothermics (CHYN) , University of Neuchâtel , 2000 Neuchâtel , Switzerland
| | - Clara Torrentó
- Centre for Hydrogeology and Geothermics (CHYN) , University of Neuchâtel , 2000 Neuchâtel , Switzerland
| | - Christina Lihl
- Helmholtz Zentrum München , Institute of Groundwater Ecology , 85764 Neuherberg , Germany
| | - Thomas B Hofstetter
- Swiss Federal Institute of Aquatic Science and Technology (Eawag) , 8600 Dübendorf , Switzerland
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics (CHYN) , University of Neuchâtel , 2000 Neuchâtel , Switzerland
| | - Martin Elsner
- Helmholtz Zentrum München , Institute of Groundwater Ecology , 85764 Neuherberg , Germany.,Chair of Analytical Chemistry and Water Chemistry , Technical University of Munich , 81377 Munich , Germany
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Masbou J, Meite F, Guyot B, Imfeld G. Enantiomer-specific stable carbon isotope analysis (ESIA) to evaluate degradation of the chiral fungicide Metalaxyl in soils. JOURNAL OF HAZARDOUS MATERIALS 2018; 353:99-107. [PMID: 29649698 DOI: 10.1016/j.jhazmat.2018.03.047] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 03/23/2018] [Accepted: 03/24/2018] [Indexed: 05/21/2023]
Abstract
Chiral pesticides are often degraded enantioselectively in soils, leading to disparity among enantiomers that may display different toxicity levels. Monitoring pesticide degradation extents and processes remains out of reach in the field using conventional bulk and enantiomer concentration analyses. Enantioselective stable carbon isotope analysis (ESIA) combines compound specific isotope analysis (CSIA) and enantioselective analysis, and bears potential to distinguish enantiomer degradation from non-destructive dissipation. We developed ESIA of the fungicide Metalaxyl, providing the 13C/12C ratios for S-Metalaxyl and R-Metalaxyl separately, and applied it to follow degradation in soil incubation experiments. Significant enantioselective degradation (kS-MTY = 0.007-0.011 day-1 < kR-MTY = 0.03-0.07 day-1) was associated with isotope fractionation (Δδ13CS-MTY ranging from 2 to 6‰). While R-Metalaxyl degradation was rapid (T1/2≈10 days), concomitant enrichment in heavy isotopes of the persistent S-Metalaxyl occurred after 200 days of incubation (εS-Metalaxyl ranging from -1.3 to -2.7‰). In contrast, initial racemic ratios and isotopic compositions were conserved in abiotic experiments, which indicates the predominance of microbial degradation in soils. Degradation products analysis and apparent kinetic isotope effect (AKIE) suggested hydroxylation as a major enantioselective degradation pathway in our soils. Altogether, our study underscores the potential of ESIA to evaluate the degradation extent and mechanisms of chiral micropollutants in soils.
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Affiliation(s)
- Jérémy Masbou
- Laboratoire d'Hydrologie et de Géochimie de Strasbourg (LHyGeS), Université de Strasbourg/EOST, CNRS, 1 rue Blessig, 67084 Strasbourg Cedex, France
| | - Fatima Meite
- Laboratoire d'Hydrologie et de Géochimie de Strasbourg (LHyGeS), Université de Strasbourg/EOST, CNRS, 1 rue Blessig, 67084 Strasbourg Cedex, France
| | - Benoît Guyot
- Laboratoire d'Hydrologie et de Géochimie de Strasbourg (LHyGeS), Université de Strasbourg/EOST, CNRS, 1 rue Blessig, 67084 Strasbourg Cedex, France
| | - Gwenaël Imfeld
- Laboratoire d'Hydrologie et de Géochimie de Strasbourg (LHyGeS), Université de Strasbourg/EOST, CNRS, 1 rue Blessig, 67084 Strasbourg Cedex, France.
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7
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Tang X, Yang Y, Huang W, McBride MB, Guo J, Tao R, Dai Y. Transformation of chlorpyrifos in integrated recirculating constructed wetlands (IRCWs) as revealed by compound-specific stable isotope (CSIA) and microbial community structure analysis. BIORESOURCE TECHNOLOGY 2017; 233:264-270. [PMID: 28285217 DOI: 10.1016/j.biortech.2017.02.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/15/2017] [Accepted: 02/17/2017] [Indexed: 06/06/2023]
Abstract
Carbon isotope analysis and 454 pyrosequencing methods were used to investigate in situ biodegradation of chlorpyrifos during its transport through three model integrated recirculating constructed wetlands (IRCWs). Results show that plant and Fe-impregnated biochar promoted degradation of chlorpyrifos and its metabolite 3,5,6-trichloro-2-pyridinol (TCP). Carbon isotope ratios in the IRCWs shifted to -31.24±0.58‰ (IRCW1, plant free), -26.82±0.60‰ (IRCW2, with plant) and -24.76±0.94‰ (IRCW3, with plant and Fe-biochar). The enrichment factors (Ɛbulk,c) were determined as -0.69±0.06‰ (IRCW1), -0.91±0.07‰ (IRCW2) and -1.03±0.09‰ (IRCW3). Microbial community analysis showed that IRCW3 was dominated by members of Bacillus, which can utilize and degrade chlorpyrifos. These results reveal that plant and Fe-biochar can induce carbon isotope fractionation and have a positive impact on the chlorpyrifos degradation efficiency by influencing the development of beneficial microbial communities.
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Affiliation(s)
- Xiaoyan Tang
- Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
| | - Yang Yang
- Institute of Hydrobiology, Jinan University, Guangzhou 510632, China; Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education, Guangzhou, China.
| | - Wenda Huang
- Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
| | - Murray B McBride
- Department of Corp and Soil Sciences, Cornell University, Ithaca, NY 14850, USA
| | - Jingjing Guo
- Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
| | - Ran Tao
- Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
| | - Yunv Dai
- Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
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Jin B, Rolle M. Joint interpretation of enantiomer and stable isotope fractionation for chiral pesticides degradation. WATER RESEARCH 2016; 105:178-186. [PMID: 27619494 DOI: 10.1016/j.watres.2016.08.057] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 08/22/2016] [Accepted: 08/27/2016] [Indexed: 06/06/2023]
Abstract
Chiral pesticides are important contaminants affecting the health and functioning of aquatic systems. The combination of stable isotope and enantiomer analysis techniques has been recently proposed to better characterize the fate of these contaminants in natural and engineered settings. We introduce a modeling approach with the aim of unifying and integrating the interpretation of isotopic and enantiomeric fractionation. The model is based on the definition of enantiomer-specific isotopologues and jointly predicts the evolution of concentration, enantiomer fractionation, as well as changes in stable isotope ratios of different elements. The method allows evaluating different transformation pathways and was applied to investigate enzymatic degradation of dichlorprop (DCPP), enzymatic degradation of mecoprop methyl ester (MCPPM), and microbial degradation of α-hexachlorocyclohexane (α-HCH) by different bacterial strains and under different redox conditions. The model accurately reproduces the isotopic and enantiomeric data observed in previous experimental studies and precisely captures the dual-dimensional trends characterizing different reaction pathways. Furthermore, the model allows testing possible combinations of enantiomer analysis (EA), compound specific isotope analysis (CSIA), and enantiomer specific isotope analysis (ESIA) to identify and assess isotope and enantiomer selective reaction mechanisms.
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Affiliation(s)
- Biao Jin
- Department of Environmental Engineering, Technical University of Denmark, Miljøvej Building 113, DK-2800 Kgs. Lyngby, Denmark
| | - Massimo Rolle
- Department of Environmental Engineering, Technical University of Denmark, Miljøvej Building 113, DK-2800 Kgs. Lyngby, Denmark.
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Elsner M, Imfeld G. Compound-specific isotope analysis (CSIA) of micropollutants in the environment - current developments and future challenges. Curr Opin Biotechnol 2016; 41:60-72. [PMID: 27340797 DOI: 10.1016/j.copbio.2016.04.014] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/14/2016] [Accepted: 04/12/2016] [Indexed: 10/21/2022]
Abstract
Over the last decade, the occurrence of micropollutants in the environment has become a worldwide issue of increasing concern. Compound-specific stable-isotope analysis (CSIA) of natural isotopic abundance may greatly enhance the evaluation of sources and transformation processes of micropollutants, such as pesticides, personal care products or pharmaceuticals. We summarize recent advances from laboratory studies, review current limitations and analytical challenges associated with low concentrations and high polarity of micropollutants, and delineate the potential of micropolluant CSIA for field applications. We highlight future challenges and prospects regarding source apportionment, identification of biotic and abiotic transformation reactions on a mechanistic level, as well as integrative evaluation of degradation hot spots on the catchment scale. Such advances may feed into a framework for risk assessment of micropollutants that includes CSIA.
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Affiliation(s)
- Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
| | - Gwenaël Imfeld
- Laboratoire d'Hydrologie et de Géochimie de Strasbourg (LHyGeS), UMR 7517, Université de Strasbourg/EOST, CNRS, 1 rue Blessig, 67084 Strasbourg Cedex, France
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10
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Schürner HKV, Maier MP, Eckert D, Brejcha R, Neumann CC, Stumpp C, Cirpka OA, Elsner M. Compound-Specific Stable Isotope Fractionation of Pesticides and Pharmaceuticals in a Mesoscale Aquifer Model. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:5729-39. [PMID: 27100740 DOI: 10.1021/acs.est.5b03828] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Compound-specific isotope analysis (CSIA) receives increasing interest for its ability to detect natural degradation of pesticides and pharmaceuticals. Despite recent laboratory studies, CSIA investigations of such micropollutants in the environment are still rare. To explore the certainty of information obtainable by CSIA in a near-environmental setting, a pulse of the pesticide bentazone, the pesticide metabolite 2,6-dichlorobenzamide (BAM), and the pharmaceuticals diclofenac and ibuprofen was released into a mesoscale aquifer with quasi-two-dimensional flow. Concentration breakthrough curves (BTC) of BAM and ibuprofen demonstrated neither degradation nor sorption. Bentazone was transformed but did not sorb significantly, whereas diclofenac showed both degradation and sorption. Carbon and nitrogen CSIA could be accomplished in similar concentrations as for "traditional" priority pollutants (low μg/L range), however, at the cost of uncertainties (0.4-0.5‰ (carbon), 1‰ (nitrogen)). Nonetheless, invariant carbon and nitrogen isotope values confirmed that BAM was neither degraded nor sorbed, while significant enrichment of (13)C and in particular (15)N corroborated transformation of diclofenac and bentazone. Retardation of diclofenac was reflected in additional (15)N sorption isotope effects, whereas isotope fractionation of transverse dispersion could not be identified. These results provide a benchmark on the performance of CSIA to monitor the reactivity of micropollutants in aquifers and may guide future efforts to accomplish CSIA at even lower concentrations (ng/L range).
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Affiliation(s)
- Heide K V Schürner
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Michael P Maier
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Dominik Eckert
- Center for Applied Geosciences, University of Tübingen , Hölderlinstraße 12, 72074 Tübingen, Germany
| | - Ramona Brejcha
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Claudia-Constanze Neumann
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Christine Stumpp
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Olaf A Cirpka
- Center for Applied Geosciences, University of Tübingen , Hölderlinstraße 12, 72074 Tübingen, Germany
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München , Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
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11
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Xu Z, Shen X, Zhang XC, Liu W, Yang F. Microbial degradation of alpha-cypermethrin in soil by compound-specific stable isotope analysis. JOURNAL OF HAZARDOUS MATERIALS 2015; 295:37-42. [PMID: 25880047 DOI: 10.1016/j.jhazmat.2015.03.062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 03/27/2015] [Accepted: 03/28/2015] [Indexed: 06/04/2023]
Abstract
To assess microbial degradation of alpha-cypermethrin in soil, attenuation of alpha-cypermethrin was investigated by compound-specific stable isotope analysis. The variations of the residual concentrations and stable carbon isotope ratios of alpha-cypermethrin were detected in unsterilized and sterilized soils spiked with alpha-cypermethrin. After an 80 days' incubation, the concentrations of alpha-cypermethrin decreased to 0.47 and 3.41 mg/kg in the unsterilized soils spiked with 2 and 10 mg/kg, while those decreased to 1.43 and 6.61 mg/kg in the sterilized soils. Meanwhile, the carbon isotope ratios shifted to -29.14 ± 0.22‰ and -29.86 ± 0.33‰ in the unsterilized soils spiked with 2 and 10 mg/kg, respectively. The results revealed that microbial degradation contributed to the attenuation of alpha-cypermethrin and induced the carbon isotope fractionation. In order to quantitatively assess microbial degradation, a relationship between carbon isotope ratios and residual concentrations of alpha-cypermethrin was established according to Rayleigh equation. An enrichment factor, ϵ = -1.87‰ was obtained, which can be employed to assess microbial degradation of alpha-cypermethrin. The significant carbon isotope fractionation during microbial degradation suggests that CSIA is a proper approach to qualitatively detect and quantitatively assess the biodegradation during attenuation process of alpha-cypermethrin in the field.
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Affiliation(s)
- Zemin Xu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaoli Shen
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Department of Environmental Engineering, Quzhou University, Quzhou 324000, China
| | - Xi-Chang Zhang
- Laboratory for Teaching in Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Weiping Liu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Fangxing Yang
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Department of Effect-Directed Analysis, Helmholtz Center for Environmental Research - UFZ, Leipzig 04318, Germany.
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12
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Badea SL, Danet AF. Enantioselective stable isotope analysis (ESIA) - a new concept to evaluate the environmental fate of chiral organic contaminants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 514:459-466. [PMID: 25687672 DOI: 10.1016/j.scitotenv.2015.01.082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/26/2015] [Accepted: 01/26/2015] [Indexed: 06/04/2023]
Abstract
Since 2011, the enantiospecific stable carbon isotope analysis (ESIA) has emerged as an innovative technique to assess the environmental fate of chiral emerging compounds by combining in one experimental technique both compound specific isotope analysis (CSIA) and enantioselective analysis. To date, the ESIA was applied for four classes of compounds: α-hexachlorocyclohexane (α-HCH), polar herbicides (phenoxy acids), synthetic polycyclic musk galaxolide (HHCB), and phenoxyalkanoic methyl herbicides. From an analytical point of view there are factors that are hindering the application of ESIA methods for the field samples: (i.e. amounts of target analyte, matrix effects, GC resolution) and overcoming these factors is challenging. While ESIA was shown as a mature technique for the first three abovementioned class of compounds, no isotope analysis of individual enantiomers could be performed for phenoxyalkanoic methyl herbicides. With respect to field studies, one study showed that ESIA might be a promising tool to distinguish between biotic and abiotic transformation pathways of chiral organic contaminants and even to differentiate between their aerobic and anaerobic biotransformation pathways. The development of ESIA methods for new chiral emerging contaminants in combination with development of multi-element isotope analysis will contribute to a better characterization of transformation pathways of chiral organic contaminants.
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Affiliation(s)
| | - Andrei-Florin Danet
- Department of Analytical Chemistry, University of Bucharest, Faculty of Chemistry, 90-92 Panduri Str., Bucharest 050657, Romania
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Qiu S, Gözdereliler E, Weyrauch P, Lopez ECM, Kohler HPE, Sørensen SR, Meckenstock RU, Elsner M. Small 13C/ 12C Fractionation Contrasts with Large Enantiomer Fractionation in Aerobic Biodegradation of Phenoxy Acids. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:5501-11. [PMID: 24708181 DOI: 10.1021/es405103g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- Shiran Qiu
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
| | - Erkin Gözdereliler
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen K, Denmark
| | - Philip Weyrauch
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
| | - Eva C. Magana Lopez
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
| | - Hans-Peter E. Kohler
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), Überlandstrasse 133, CH-8600 Dübendorf, Switzerland
| | - Sebastian R. Sørensen
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen K, Denmark
| | - Rainer U. Meckenstock
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
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14
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Jammer S, Voloshenko A, Gelman F, Lev O. Chiral and isotope analyses for assessing the degradation of organic contaminants in the environment: Rayleigh dependence. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3310-3318. [PMID: 24471759 DOI: 10.1021/es4039209] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The Rayleigh equation is frequently used to describe isotope fractionation as a function of conversion. In this article we propose to draw a parallel between isotope and enantiomeric enrichments and derive a set of conditions that allow the use of the Rayleigh approach to describe the enantiomeric enrichment-conversion dependencies. We demonstrate an implementation of the Rayleigh equation for the enantioselective enzymatic hydrolysis of Mecoprop-methyl, Dichlorprop-methyl, and dimethyl-methylsuccinate by lipases from Pseudomonas fluorescens, Pseudomonas cepacia, and Candida rugosa. The data obtained for all the studied reactions gave good fits to the Rayleigh equation, with a linear regression R(2) > 0.96. In addition to that, our analysis of four microcosm studies on the hydrolysis of the individual enantiomers of Dichloroprop methyl, Lactofen, Fenoxaprop-ethyl, and Metalaxyl reported in the literature by other research groups revealed a suitability of the Rayleigh dependence. Two dimensional plots describing the isotope fractionation versus enantiomeric enrichment are demonstrated for all studied cases. Processes not accompanied by enantiomeric enrichment (acid and base hydrolysis) and by isotope enrichment (transesterification) are demonstrated, their 2-D plots are either horizontal or vertical which can illuminate concealed degradation pathways.
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Affiliation(s)
- S Jammer
- The Casali Center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
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15
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Elsayed OF, Maillard E, Vuilleumier S, Nijenhuis I, Richnow HH, Imfeld G. Using compound-specific isotope analysis to assess the degradation of chloroacetanilide herbicides in lab-scale wetlands. CHEMOSPHERE 2014; 99:89-95. [PMID: 24256720 DOI: 10.1016/j.chemosphere.2013.10.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 10/03/2013] [Accepted: 10/14/2013] [Indexed: 06/02/2023]
Abstract
Compound-specific isotope analysis (CSIA) is a promising tool to study the environmental fate of a wide range of contaminants including pesticides. In this study, a novel CSIA method was developed to analyse the stable carbon isotope signatures of widely used chloroacetanilide herbicides. The developed method was applied in combination with herbicide concentration and hydrochemical analyses to investigate in situ biodegradation of metolachlor, acetochlor and alachlor during their transport in lab-scale wetlands. Two distinct redox zones were identified in the wetlands. Oxic conditions prevailed close to the inlet of the four wetlands (oxygen concentration of 212±24μM), and anoxic conditions (oxygen concentrations of 28±41μM) prevailed towards the outlet, where dissipation of herbicides mainly occurred. Removal of acetochlor and alachlor from inlet to outlet of wetlands was 56% and 51%, whereas metolachlor was more persistent (23% of load dissipation). CSIA of chloroacetanilides at the inlet and outlet of the wetlands revealed carbon isotope fractionation of alachlor (εbulk=-2.0±0.3‰) and acetochlor (εbulk=-3.4±0.5‰), indicating that biodegradation contributes to the dissipation of both herbicides. This study is a first step towards the application of CSIA to evaluate the transport and degradation of chloroacetanilide herbicides in the environment.
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Affiliation(s)
- O F Elsayed
- Laboratory of Hydrology and Geochemistry of Strasbourg (LHyGeS), UMR 7517, University of Strasbourg/ENGEES, CNRS, France; Génétique Moléculaire, Génomique, Microbiologie (GMGM), UMR 7156, University of Strasbourg, CNRS, France
| | - E Maillard
- Laboratory of Hydrology and Geochemistry of Strasbourg (LHyGeS), UMR 7517, University of Strasbourg/ENGEES, CNRS, France
| | - S Vuilleumier
- Génétique Moléculaire, Génomique, Microbiologie (GMGM), UMR 7156, University of Strasbourg, CNRS, France
| | - I Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
| | - H H Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
| | - G Imfeld
- Laboratory of Hydrology and Geochemistry of Strasbourg (LHyGeS), UMR 7517, University of Strasbourg/ENGEES, CNRS, France.
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16
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Maier MP, De Corte S, Nitsche S, Spaett T, Boon N, Elsner M. C & N isotope analysis of diclofenac to distinguish oxidative and reductive transformation and to track commercial products. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:2312-20. [PMID: 24397428 DOI: 10.1021/es403214z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Although diclofenac is frequently found in aquatic systems, its degradability in the environment remains imperfectly understood. On the one hand, evidence from concentration analysis alone is inconclusive if an unknown hydrology impedes a distinction between degradation and dilution. On the other hand, not all transformation products may be detectable. As a new approach, we therefore developed GC-IRMS (gas chromatography-isotope-ratio mass-spectrometry) analysis for carbon and nitrogen isotope measurements of diclofenac. The method uses a derivatization step that can be conducted either online or offline, for optimized throughput or sensitivity, respectively. In combination with on-column injection, the latter method enables determination of diclofenac isotope ratios down to the sub-μgL(-1) range in environmental samples. Degradation in an aerobic sediment-water system showed strong nitrogen isotope fractionation (εN = -7.1‰), whereas reductive diclofenac dechlorination was associated with significant carbon isotope fractionation (εC = -2.0‰). Hence dual element isotope analysis bears potential not only to detect diclofenac degradation, but even to distinguish both transformation pathways in the environment. In an explorative survey, analysis of commercial diclofenac products showed significant differences in carbon and nitrogen isotope ratios, demonstrating a further potential to track, and potentially even to authenticate, commercial production batches.
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Affiliation(s)
- Michael P Maier
- Helmholtz Zentrum Muenchen, German Research Center, Institute of Groundwater Ecology , Ingolstädter Landstrasse 1, Neuherberg D-85764, Germany
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