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Dou Q, Canavan A, Fu Y, Xiang L, Wang Y, Wang X, Jiang X, Dirr C, Wang F, Elsner M. Nitrogen stable isotope analysis of sulfonamides by derivatization-gas chromatography-isotope ratio mass spectrometry. Anal Bioanal Chem 2024; 416:4237-4247. [PMID: 38849528 DOI: 10.1007/s00216-024-05361-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 06/09/2024]
Abstract
The continuous introduction of micropollutants into the environment through livestock farming, agricultural practices, and wastewater treatment is a major concern. Among these pollutants are synthetic sulfonamide antibiotics such as sulfamethoxazole, which are not always fully degraded and pose a risk of fostering antimicrobial resistance. It is challenging to assess the degradation of sulfonamides with conventional concentration measurements. This study introduces compound-specific isotope analysis of nitrogen isotope ratios at natural abundances by derivatization-gas chromatography hyphenated with isotope ratio mass spectrometry (derivatization-GC-IRMS) as a new and more precise method for tracing the origin and degradation of sulfonamides. Here, sulfamethoxazole was used as a model compound to develop and optimize the derivatization conditions using (trimethylsilyl)diazomethane as a derivatization reagent. With the optimized conditions, accurate and reproducible δ15N analysis of sulfamethoxazole by derivatization-GC-IRMS was achieved in two different laboratories with a limit for precise isotope analysis of 3 nmol N on column, corresponding to 0.253 µg non-derivatized SMX. Application of the method to four further sulfonamides, sulfadiazine, sulfadimethoxine, sulfadimidine, and sulfathiazole, shows the versatility of the developed method. Its benefit was demonstrated in a first application, highlighting the possibility of distinguishing sulfamethoxazole from different suppliers and pharmaceutical products.
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Affiliation(s)
- Qingyuan Dou
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Science, Beijing, 100049, China
| | - Aoife Canavan
- Chair of Analytical Chemistry and Water Chemistry, School of Natural Sciences, Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85748, Garching, Germany
| | - Yuhao Fu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Science, Beijing, 100049, China
| | - Leilei Xiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Science, Beijing, 100049, China
| | - Yu Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Science, Beijing, 100049, China
| | - Xi Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Science, Beijing, 100049, China
| | - Xin Jiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Science, Beijing, 100049, China
| | - Christopher Dirr
- Chair of Analytical Chemistry and Water Chemistry, School of Natural Sciences, Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85748, Garching, Germany
| | - Fang Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing, 210008, China.
- University of Chinese Academy of Science, Beijing, 100049, China.
| | - Martin Elsner
- Chair of Analytical Chemistry and Water Chemistry, School of Natural Sciences, Department of Chemistry, Technical University of Munich, Lichtenbergstr. 4, 85748, Garching, Germany.
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2
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Vinyes-Nadal M, Masbou J, Kümmel S, Gehre M, Imfeld G, Otero N, Torrentó C. Novel extraction methods and compound-specific isotope analysis of methoxychlor in environmental water and aquifer slurry samples. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172858. [PMID: 38714260 DOI: 10.1016/j.scitotenv.2024.172858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/09/2024]
Abstract
Multi-element compound-specific stable isotope analysis (ME-CSIA) allows monitoring the environmental behavior and transformation of most common and persistent contaminants. Recent advancements in analytical techniques have extended the applicability of ME-CSIA to organic micropollutants, including pesticides. Nevertheless, the application of this methodology remains unexplored concerning harmful insecticides such as methoxychlor, a polar organochlorine pesticide usually detected in soil and groundwater. This study introduces methods for dual carbon and chlorine compound-specific stable isotope analysis (δ13C-CSIA and δ37Cl-CSIA) of both methoxychlor and its metabolite, methoxychlor olefin, with a sensitivity down to 10 and 100 mg/L, and a precision lower than 0.3 and 0.5 ‰ for carbon and chlorine CSIA, respectively. Additionally, three extraction and preconcentration techniques suitable for ME-CSIA of the target pesticides at environmentally relevant concentrations were also developed. Solid-phase extraction (SPE) and liquid-solid extraction (LSE) effectively extracted methoxychlor (107 ± 27 % and 87 ± 13 %, respectively) and its metabolite (91 ± 27 % and 106 ± 14 %, respectively) from water and aquifer slurry samples, respectively, with high accuracy (Δδ13C and Δδ37Cl ≤ ± 1 ‰). Combining CSIA with polar organic chemical integrative samplers (POCISs) for the extraction of methoxychlor and methoxychlor olefin from water samples resulted in insignificant fractionation for POCIS-CSIA (Δδ13C ≤ ± 1 ‰). A relevant sorption of methoxychlor was detected within the polyethersulfones membranes of the POCISs resulting in temporary carbon isotope fractionation depending on the sorbed mass fraction during the first deployment days. This highlights the critical role of the interactions of polar analytes with POCIS sorbents and membranes in the performance of this method. Altogether, this study proposes a proof of concept for ME-CSIA of methoxychlor and its metabolites, opening the door for future investigations of their sources and transformation processes in contaminated sites.
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Affiliation(s)
- Martí Vinyes-Nadal
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí i Franquès s/n, 08028 Barcelona, Spain.
| | - Jérémy Masbou
- Université de Strasbourg, CNRS/ENGEES, ITES UMR 7063, Institut Terre et Environnement de Strasbourg, Strasbourg, France.
| | - Steffen Kümmel
- Department of Technical Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, Leipzig 04318, Germany.
| | - Matthias Gehre
- Department of Technical Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, Leipzig 04318, Germany.
| | - Gwenaël Imfeld
- Université de Strasbourg, CNRS/ENGEES, ITES UMR 7063, Institut Terre et Environnement de Strasbourg, Strasbourg, France.
| | - Neus Otero
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí i Franquès s/n, 08028 Barcelona, Spain; Serra Húnter Fellowship, Generalitat de Catalunya, Spain.
| | - Clara Torrentó
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Hidrogeologia (MAGH), Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí i Franquès s/n, 08028 Barcelona, Spain; Serra Húnter Fellowship, Generalitat de Catalunya, Spain.
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3
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Wabnitz C, Chen W, Elsner M, Bakkour R. Quartz Crystal Microbalance as a Holistic Detector for Quantifying Complex Organic Matrices during Liquid Chromatography: 2. Compound-Specific Isotope Analysis. Anal Chem 2024; 96:7436-7443. [PMID: 38700939 PMCID: PMC11099894 DOI: 10.1021/acs.analchem.3c05441] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/22/2024] [Accepted: 04/17/2024] [Indexed: 05/05/2024]
Abstract
In carbon-compound-specific isotope analysis (carbon CSIA) of environmental micropollutants, purification of samples is often required to guarantee accurate measurements of a target compound. A companion paper has brought forward an innovative approach to couple a quartz crystal microbalance (QCM) with high-performance liquid chromatography (HPLC) for the online quantification of matrices during a gradient HPLC purification. This work investigates the benefit for isotope analysis of polar micropollutants typically present in environmental samples. Here, we studied the impact of the natural organic matter (NOM) on the isotopic integrity of model analytes and the suitability of the NOM-to-analyte ratio as a proxy for the sample purity. We further investigated limitations and enhancement of HPLC purification using QCM on C18 and C8 phases for single and multiple targets. Strong isotopic shifts of up to 3.3% toward the isotopic signature of NOM were observed for samples with an NOM-to-analyte ratio ≥10. Thanks to QCM, optimization of matrix removal of up to 99.8% of NOM was possible for late-eluting compounds. The efficiency of HPLC purification deteriorated when aiming for simultaneous purification of two or three compounds, leading to up to 2.5% less NOM removal. Our results suggest that one optimized HPLC purification can be achieved through systematic screening of 3 to 5 different gradients, thereby leading to a shift of the boundaries of accurate carbon CSIA by up to 2 orders of magnitude toward lower micropollutant concentrations.
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Affiliation(s)
- Christopher Wabnitz
- Department of Chemistry, Chair of Analytical
Chemistry and Water Chemistry, TUM School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Wei Chen
- Department of Chemistry, Chair of Analytical
Chemistry and Water Chemistry, TUM School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Martin Elsner
- Department of Chemistry, Chair of Analytical
Chemistry and Water Chemistry, TUM School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching, Germany
| | - Rani Bakkour
- Department of Chemistry, Chair of Analytical
Chemistry and Water Chemistry, TUM School of Natural Sciences, Technical University of Munich, Lichtenbergstr. 4, 85748 Garching, Germany
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van der Waals MJ, Thornton SF, Rolfe SA, Rock L, Smith JWN, Bosma TNP, Gerritse J. Potential of stable isotope analysis to deduce anaerobic biodegradation of ethyl tert-butyl ether (ETBE) and tert-butyl alcohol (TBA) in groundwater: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:16150-16163. [PMID: 38319419 PMCID: PMC10894111 DOI: 10.1007/s11356-024-32109-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 01/17/2024] [Indexed: 02/07/2024]
Abstract
Understanding anaerobic biodegradation of ether oxygenates beyond MTBE in groundwater is important, given that it is replaced by ETBE as a gasoline additive in several regions. The lack of studies demonstrating anaerobic biodegradation of ETBE, and its product TBA, reflects the relative resistance of ethers and alcohols with a tertiary carbon atom to enzymatic attack under anoxic conditions. Anaerobic ETBE- or TBA-degrading microorganisms have not been characterized. Only one field study suggested anaerobic ETBE biodegradation. Anaerobic (co)metabolism of ETBE or TBA was reported in anoxic microcosms, indicating their biodegradation potential in anoxic groundwater systems. Non-isotopic methods, such as the detection of contaminant loss, metabolites, or ETBE- and TBA-degrading bacteria are not sufficiently sensitive to track anaerobic biodegradation in situ. Compound- and position-specific stable isotope analysis provides a means to study MTBE biodegradation, but isotopic fractionation of ETBE has only been studied with a few aerobic bacteria (εC -0.7 to -1.7‰, εH -11 to -73‰) and at one anoxic field site (δ2H-ETBE +14‰). Similarly, stable carbon isotope enrichment (δ13C-TBA +6.5‰) indicated TBA biodegradation at an anoxic field site. CSIA and PSIA are promising methods to detect anaerobic ETBE and TBA biodegradation but need to be investigated further to assess their full potential at field scale.
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Affiliation(s)
- Marcelle J van der Waals
- Unit Subsurface and Groundwater Systems, Deltares, Daltonlaan 600, Utrecht, 3484 BK, The Netherlands
- Present address: KWR Water Research Institute, Groningenhaven 7, 3433 PE, Nieuwegein, The Netherlands
| | - Steven F Thornton
- Department of Civil and Structural Engineering, University of Sheffield, Mappin St, Sheffield, S1 3JD, UK
| | - Stephen A Rolfe
- School of Biosciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Luc Rock
- Shell Global Solutions International BV, Carel van Bylandtlaan 30, The Hague, 2596 HR, The Netherlands
- Present address: Shell Global Solutions (Canada) Inc, 4000 - 500 Centre Street SE, Calgary, AB, T2G 1A6, Canada
| | - Jonathan W N Smith
- Shell Global Solutions (UK) Ltd, Shell Centre, York Road, London, SE1 7NA, UK
| | - Tom N P Bosma
- Unit Subsurface and Groundwater Systems, Deltares, Daltonlaan 600, Utrecht, 3484 BK, The Netherlands
| | - Jan Gerritse
- Unit Subsurface and Groundwater Systems, Deltares, Daltonlaan 600, Utrecht, 3484 BK, The Netherlands.
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Martin PR, Buchner D, Jochmann MA, Haderlein SB. Dispersive liquid-liquid microextraction as a novel enrichment approach for compound-specific carbon isotope analysis of chlorinated phenols. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024; 16:919-929. [PMID: 38258526 DOI: 10.1039/d3ay01981k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Compound-specific isotope analysis (CSIA) via gas chromatography-isotope ratio mass spectrometry (GC-IRMS) is a potent tool to elucidate the fate of (semi-)volatile organic contaminants in technical and environmental systems. Yet, due to the comparatively low sensitivity of IRMS, an enrichment step prior to analysis often is inevitable. A promising approach for fast as well as economic analyte extraction and preconcentration prior to CSIA is dispersive liquid-liquid microextraction (DLLME) - a well-established technique in concentration analysis of contaminants from aqueous samples. Here, we present and evaluate the first DLLME method for GC-IRMS exemplified by the analysis of chlorinated phenols (4-chlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol) as model compounds. The analytes were simultaneously acetylated with acetic anhydride and extracted from the aqueous phase using a binary solvent mixture of acetone and tetrachloroethylene. With this method, reproducible δ13C values were achieved with errors ≤ 0.6‰ (n = 3) for aqueous concentrations down to 100 μg L-1. With preconcentration factors between 130 and 220, the method outperformed conventional liquid-liquid extraction in terms of sample preparation time and resource consumption with comparable reproducibility. Furthermore, we have demonstrated the suitability of the method (i) for the extraction of the analytes from a spiked river water sample and (ii) to quantify kinetic carbon isotope effect for 2,4,6-trichlorophenol during reduction with zero-valent zinc in a laboratory batch experiment. The presented work shows for the first time the potential of DLLME for analyte enrichment prior to CSIA and paves the way for further developments, such as the extraction of other compounds or scaling up to larger sample volumes.
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Affiliation(s)
- Philipp R Martin
- Department of Geosciences, Eberhard Karls University Tübingen, Schnarrenbergstr. 94-96, D-72076 Tübingen, Germany.
| | - Daniel Buchner
- Department of Geosciences, Eberhard Karls University Tübingen, Schnarrenbergstr. 94-96, D-72076 Tübingen, Germany.
| | - Maik A Jochmann
- Instrumental Analytical Chemistry, University of Duisburg-Essen, D-45141 Essen, Germany
| | - Stefan B Haderlein
- Department of Geosciences, Eberhard Karls University Tübingen, Schnarrenbergstr. 94-96, D-72076 Tübingen, Germany.
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Tian B, Gao S, Zhu Z, Zeng X, Liang Y, Yu Z, Peng P. Two-dimensional gas chromatography coupled to isotope ratio mass spectrometry for determining high molecular weight polycyclic aromatic hydrocarbons in sediments. J Chromatogr A 2023; 1693:463879. [PMID: 36822039 DOI: 10.1016/j.chroma.2023.463879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/12/2023] [Accepted: 02/16/2023] [Indexed: 02/21/2023]
Abstract
The accuracy of compound-specific isotope analysis (CSIA) of trace-level pollutants in complex environmental samples has always been limited by two main challenges: poor chromatographic separation and insufficient amounts of analytes. In this study, a two-dimensional gas chromatography-isotope ratio mass spectrometry (2DGC-IRMS) system was constructed for compound-specific δ13C analysis of high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) in estuarine/marine sediments. This construction occurred through hyphenating an extra gas chromatography system (GC) to a conventional GC-IRMS using a commercially available multi-column switching-cryogenic trapping system (MCS-CTS). Compared with the previous 2DGC-IRMS strategy, which utilizes a Deans Switch device, the newly implemented 2DGC-IRMS scheme resulted in online purification of target analytes as well as enriched them online via duplicate injection and cryogenic trapping in CTS; this resultingly lowered the limits of detection (LOD) of CSIA. To improve the sample transfer efficiency to the IRMS, a broader-bore and longer fused-silica capillary was utilized to replace the original sample capillary running from the sample open split to the IRMS. A ẟ13C analysis of PAH standards showed accurate ẟ13C values, and high precisions (standard deviations 0.13-0.37%) were achieved, with the LOD of HMW-PAHs reduced to at least 1.0 mg/L (i.e., 0.07 to 0.09 nmol carbon per compound on-column). The successful application of this newly developed 2DGC-IRMS scheme provides a practical solution for the reliable CSIA of trace-level pollutants in complex environmental samples that cannot be measured using the conventional GC-IRMS system.
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Affiliation(s)
- Boyang Tian
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shutao Gao
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China.
| | - Zhanjun Zhu
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiangying Zeng
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Yi Liang
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Zhiqiang Yu
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Ping'an Peng
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
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Khatri PK, Paolini M, Larcher R, Ziller L, Alina Magdas D, Marincas O, Roncone A, Bontempo L. Validation of gas chromatographic methods for lavender essential oil authentication based on volatile organic compounds and stable isotope ratios. Microchem J 2022. [DOI: 10.1016/j.microc.2022.108343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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8
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Managing argon interference during measurements of 18O/ 16O ratios in O 2 by continuous-flow isotope ratio mass spectrometry. Anal Bioanal Chem 2022; 414:6177-6186. [PMID: 35841416 PMCID: PMC9314310 DOI: 10.1007/s00216-022-04184-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/08/2022] [Accepted: 06/17/2022] [Indexed: 11/08/2022]
Abstract
Abstract Monitoring changes in stable oxygen isotope ratios in molecular oxygen allows for studying many fundamental processes in bio(geo)chemistry and environmental sciences. While the measurement of \documentclass[12pt]{minimal}
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\begin{document}$$\mathrm {O}_{2}$$\end{document}O2 in gaseous samples can be carried out conveniently and from extracting moderately small aqueous samples for analyses by continuous-flow isotope ratio mass spectrometry (CF-IRMS), oxygen isotope signatures, \documentclass[12pt]{minimal}
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\begin{document}$$\permille$$\end{document}‱ because of interferences from argon in air. Here, we systematically evaluated the extent of such Ar interferences on \documentclass[12pt]{minimal}
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\begin{document}$$^{16}$$\end{document}16O ratios of \documentclass[12pt]{minimal}
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\begin{document}$$\mathrm {O}_{2}$$\end{document}O2 for measurements by gas chromatography/IRMS and GasBench/IRMS and propose simple instrumental modifications for improved Ar and \documentclass[12pt]{minimal}
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\begin{document}$$\mathrm {O}_{2}$$\end{document}O2 separation as well as post-measurement correction procedures for obtaining accurate \documentclass[12pt]{minimal}
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\begin{document}$$\updelta ^{18}$$\end{document}δ18O. We subsequently evaluated the consequences of Ar interferences for the quantification of O isotope fractionation in terms of isotope enrichment factors, \documentclass[12pt]{minimal}
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\begin{document}$$^{18}$$\end{document}18O kinetic isotope effects (\documentclass[12pt]{minimal}
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\begin{document}$$^{18}$$\end{document}18O KIEs) in samples where \documentclass[12pt]{minimal}
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\begin{document}$$\mathrm {O}_{2}$$\end{document}O2 is consumed and Ar:\documentclass[12pt]{minimal}
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\begin{document}$$\mathrm {O}_{2}$$\end{document}O2 ratios increase steadily and substantially over the course of a reaction. We show that the extent of O isotope fractionation is overestimated only slightly and that this effect is typically smaller than uncertainties originating from the precision of \documentclass[12pt]{minimal}
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\begin{document}$$\updelta ^{18}$$\end{document}δ18O measurements and experimental variability. Ar interferences can become more relevant and bias \documentclass[12pt]{minimal}
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\begin{document}$$\upepsilon _{\mathrm {O}}$$\end{document}ϵO values by more than \documentclass[12pt]{minimal}
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\begin{document}$$\mathrm {O}_{2}$$\end{document}O2 conversion exceeds 90%. Practically, however, such samples would typically contain less than 25 \documentclass[12pt]{minimal}
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\begin{document}$$^{16}$$\end{document}16O ratio measurement by CF-IRMS. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1007/s00216-022-04184-3.
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Stable Carbon Isotope Analysis of Hexachlorocyclohexanes by Liquid–Liquid Extraction Gas Chromatography Isotope Ratio Mass Spectrometry: Method Evaluation and Applications. Molecules 2022; 27:molecules27092874. [PMID: 35566221 PMCID: PMC9102580 DOI: 10.3390/molecules27092874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/24/2022] [Accepted: 04/28/2022] [Indexed: 11/17/2022] Open
Abstract
Compound specific isotope analysis (CSIA) and enantiomer specific isotope analysis (ESIA) are powerful tools for assessing the fate of hexachlorocyclohexanes (HCHs) in the environment. However, there is no systematic study on the CSIA and ESIA analysis test methods of the carbon isotopes of HCHs in water and soil environments, in particular the isotope fractionation in the pre-concentration process. We endeavored to test the compatibility of CSIA and ESIA with the liquid–liquid extraction method of HCHs in water. The results showed that there were negligible changes in the δ13C of HCHs after extraction, indicating that liquid–liquid extraction can be used as a pre-concentration method for the determination of δ13C of HCHs in water. The optimized method was validated and then applied to differentiate three HCHs from different manufacturers, to identify in situ degradation of HCHs of groundwater from a contaminated site and to resolve the carbon isotope fractionation occurring in the α-HCH oxidation by CaO2/Fe(II) Fenton system. The results showed that the same reagents from different manufacturers have different carbon isotope compositions, and different isomers from the same manufacturer also have different isotope compositions, showing useful evidence in identifying the source of HCHs. The more enriched δ13C in the down-gradient wells indicated that HCHs have undergone biodegradation or/and chemical reactions in the groundwater system of the site. Carbon isotopic enrichment factors (εC) of −1.90 ± 0.10‰ were obtained in the oxidation process. Hence, the method validated in this study has great potential as a method for identifying the degradation of HCHs in a water environment.
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10
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Compound-specific carbon isotope analysis of volatile organic compounds in complex soil extracts using purge and trap concentration coupled to heart-cutting two-dimensional gas chromatography-isotope ratio mass spectrometry. J Chromatogr A 2021; 1655:462480. [PMID: 34479096 DOI: 10.1016/j.chroma.2021.462480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/22/2021] [Accepted: 08/14/2021] [Indexed: 11/20/2022]
Abstract
Compound-specific carbon isotope analysis (CSIA) is a powerful tool to track the origin and fate of organic subsurface contaminants including petroleum and chlorinated hydrocarbons and is typically applied to water samples. However, soil can form a significant contaminant reservoir. In soil samples, it can be challenging to recover sufficient amounts of volatile organic compounds (VOC) to perform CSIA. Soil samples often contain complex contaminant mixtures and gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) is highly dependent on good chromatographic separation due to the conversion to a single analyte. To extend the applicability of CSIA to complex volatile organic compound mixtures in soil samples, and to recover sufficient amounts of target compounds for carbon CSIA, we compared two soil extraction solvents, tetraglyme (TGDE) and methanol, and developed a heart-cutting two-dimensional GC-GC-C-IRMS method. We used purge & trap concentration of solvent-water mixtures to increase the amount of analyte delivered to the column and thus lower method detection limits. We optimized purge & trap and chromatographic parameters for twelve target compounds, including one suffering from poor purge efficiency. By using a 30 m thick-film non-polar column in the first and a 15 m polar column in the second dimension, we achieved good chromatographic separation for the target compounds in difficult matrices and high accuracy (trueness and precision) for carbon isotopic analysis. Tetraglyme extraction was shown to offer advantages over methanol for purge & trap concentration, leading to lower target compound method detection limits for CSIA of soil samples. The applicability of the developed method was demonstrated for a case study on soil extracts from a former manufacturing facility. Our approach extends the applicability of CSIA to an important matrix that often controls the long-term fate of contaminants in the subsurface.
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11
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Tong Y, Berens MJ, Ulrich BA, Bolotin J, Strehlau JH, Hofstetter TB, Arnold WA. Exploring the Utility of Compound-Specific Isotope Analysis for Assessing Ferrous Iron-Mediated Reduction of RDX in the Subsurface. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6752-6763. [PMID: 33900746 DOI: 10.1021/acs.est.0c08420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Subsurface contamination with the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) at ordnance production and testing sites is a problem because of the persistence, mobility, and toxicity of RDX and the formation of toxic products under anoxic conditions. While the utility of compound-specific isotope analysis for inferring natural attenuation pathways from stable isotope ratios has been demonstrated, the stable isotope fractionation for RDX reduction by iron-bearing minerals remains unknown. Here, we evaluated N and C isotope fractionation of RDX during reduction by Fe(II) associated with Fe minerals and natural sediments and applied N isotope ratios to the assessment of mineral-catalyzed RDX reduction in a contaminant plume and in sediment columns treated by in situ chemical reduction. Laboratory studies revealed that RDX was reduced to nitroso compounds without denitration and the concomitant ring cleavage. Fe(II)/iron oxide mineral-catalyzed reactions exhibited N isotope enrichment factors, εN, between -6.3±0.3‰ and -8.2±0.2‰, corresponding to an apparent 15N kinetic isotope effect of 1.04-1.05. The observed variations of the δ15N of ∼15‰ in RDX from groundwater samples suggested an extent of reductive transformation of 85% at an ammunition plant. Conversely, we observed masking of N isotope fractionation after RDX reduction in laboratory flow-through systems, which was presumably due to limited accessibility to reactive Fe(II).
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Affiliation(s)
- Yiran Tong
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, United States
| | - Matthew J Berens
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, United States
| | - Bridget A Ulrich
- Department of Environmental Chemistry, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland
| | - Jakov Bolotin
- Department of Environmental Chemistry, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland
| | - Jennifer H Strehlau
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, United States
| | - Thomas B Hofstetter
- Department of Environmental Chemistry, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland
| | - William A Arnold
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, United States
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Droz B, Drouin G, Maurer L, Villette C, Payraudeau S, Imfeld G. Phase Transfer and Biodegradation of Pesticides in Water-Sediment Systems Explored by Compound-Specific Isotope Analysis and Conceptual Modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:4720-4728. [PMID: 33761249 DOI: 10.1021/acs.est.0c06283] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Current approaches are often limited to evaluating the contribution of pesticide dissipation processes in water-sediment systems as both degradation and phase transfer, that is, sorption-desorption, contribute to the apparent decrease of pesticide concentration. Here, the dissipation of widely used herbicides acetochlor and S-metolachlor was examined in laboratory by water-sediment microcosm experiments under oxic and anoxic conditions. Compound-specific isotope analysis (CSIA) emphasized insignificant carbon isotope fractionation in the sediment, indicating prevailing pesticide degradation in the water phase. Conceptual modeling accounting for phase transfer and biodegradation indicated that biodegradation may be underestimated when phase transfer is not included. Phase transfer does not affect carbon isotope fractionation for a wide spectrum of molecules and environmental conditions, underscoring the potential of pesticide CSIA as a robust approach to evaluate degradation in water-sediment systems. CSIA coupled with the identification of transformation products by high-resolution tandem mass spectrometry suggests the degradation of acetochlor and S-metolachlor to occur via nucleophilic substitution and the predominance of oxalinic acids as transformation products under both anoxic and oxic conditions. Altogether, combining the pesticide CSIA, the identification of transformation products, and the use of conceptual phase-transfer models improves the interpretation of pesticide dissipation in water-sediment systems.
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Affiliation(s)
- Boris Droz
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg/EOST/ENGEES, CNRS UMR 7063, 5 rue Descartes, F-67084 Strasbourg, France
| | - Guillaume Drouin
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg/EOST/ENGEES, CNRS UMR 7063, 5 rue Descartes, F-67084 Strasbourg, France
| | - Loïc Maurer
- Plant Imaging and Mass Spectrometry (PIMS), Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, CNRS, 12 rue du Général Zimmer, 67084 Strasbourg, France
- Département Mécanique, ICube Laboratoire des Sciences de l'ingénieur, de l'informatique et de l'imagerie, Université de Strasbourg/ENGEES, INSA, CNRS, 2 rue Boussingault, 67000 Strasbourg, France
| | - Claire Villette
- Plant Imaging and Mass Spectrometry (PIMS), Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, CNRS, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Sylvain Payraudeau
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg/EOST/ENGEES, CNRS UMR 7063, 5 rue Descartes, F-67084 Strasbourg, France
| | - Gwenaël Imfeld
- Institut Terre et Environnement de Strasbourg (ITES), Université de Strasbourg/EOST/ENGEES, CNRS UMR 7063, 5 rue Descartes, F-67084 Strasbourg, France
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Limon AW, Moingt M, Widory D. The carbon stable isotope compositions of glyphosate and aminomethylphosphonic acid (AMPA): Improved analytical sensitivity and first application to environmental water matrices. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9017. [PMID: 33270272 DOI: 10.1002/rcm.9017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
RATIONALE The presence of glyphosate and its degradation product aminomethylphosphonic acid (AMPA) in the environment has adverse effects on environmental quality, raising the need to better constrain their fates, in particular the processes that control their production and degradation. Our aim was to improve the sensitivity of their δ13 C analysis and demonstrate the feasibility of measuring them in natural surface water. METHODS The δ13 C values of dissolved glyphosate and AMPA were determined using isotope ratio mass spectrometry (IRMS) (Delta V Plus instrument) coupled to a high-performance liquid chromatography (HPLC) unit, where glyphosate and AMPA were separated on a Hypercarb column. RESULTS We demonstrated an improved sensitivity of the δ13 C analysis for glyphosate and AMPA by LC/IRMS compared with previous studies. For waters from the carbonate and silicate hydrofacies, while no pretreatment was required for the isotope analysis of glyphosate, removal by H3 PO4 acidification of dissolved inorganic carbon, that co-elutes with AMPA, was required prior to its analysis. We successfully tested a freeze-drying pre-concentration method showing no associated isotope fractionation up to concentration factors of 500 and 50 for glyphosate and AMPA, respectively. CONCLUSIONS We demonstrated, for the first time, the feasibility of measuring the δ13 C values of glyphosate and AMPA in natural surface waters with contrasted hydrofacies (calcium carbonate and silicate types). This opens new fields in pesticide research, especially on the characterization of processes that control their degradation and the production of their secondary byproducts.
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Affiliation(s)
- A Williams Limon
- GEOTOP/Université du Québec à Montréal, case postale 8888, , Montréal, QC, H3C 3P8, Canada
| | - Matthieu Moingt
- GEOTOP/Université du Québec à Montréal, case postale 8888, , Montréal, QC, H3C 3P8, Canada
| | - David Widory
- GEOTOP/Université du Québec à Montréal, case postale 8888, , Montréal, QC, H3C 3P8, Canada
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Asfaw BA, Sakaguchi-Söder K, Bernstein A, Siebner H, Schüth C. Optimization of compound-specific chlorine stable isotope analysis of chloroform using the Taguchi design of experiments. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8922. [PMID: 32770575 DOI: 10.1002/rcm.8922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/28/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE Chloroform, a probable human carcinogen, is commonly detected in various concentration levels in many surface water and groundwater sources. Compound-specific chlorine stable isotope analysis (Cl-CSIA) is significant in investigating the fate of chlorinated contaminants in the environment. Analytical conditions should, however, be thoroughly examined for any isotopic fractionation. In this study, we simultaneously optimize three analytical parameters for a robust online Cl-CSIA of chloroform using the Taguchi design of experiments. METHODS For Cl-CSIA, a purge-and-trap autosampler coupled to a gas chromatograph in tandem with a quadrupole mass spectrometer, with electron ionization in selected ion monitoring (SIM) mode, was used. Using the Taguchi method, the dominant parameter affecting the results of Cl-CSIA for chloroform was identified through concurrent investigation of the signal-to-noise ratios (S/N) of three parameters, each at three levels: purging time (5, 10, 15 min), transfer time (80, 120, 160 s), and dwell time (20, 60, 100 ms). Moreover, the optimum combination of the levels was identified. RESULTS The purging time, with a maximum S/N, resulted in the highest influence on the isotope ratios determined. It was further refined through additional experiments to sufficiently extract chloroform from the aqueous phase. Accordingly, 8 min of purging time, 120 s transfer time and 100 ms dwell time were the optimum conditions for Cl-CSIA of chloroform. Post-optimization, a precision of ±0.28 ‰ was achieved for 8.4 nmol of chloroform (equivalent to 0.89 μg or approx. 25 nmol Cl-mass on column). CONCLUSIONS A simple online method for Cl-CSIA of chloroform was optimized with the Taguchi design of experiments. The Taguchi method was very useful for the optimization of the analytical conditions. However, the purging conditions should be fine-tuned and selected so that sufficient extraction of a target compound is confirmed to acquire a stable and higher precision of the method.
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Affiliation(s)
- Berhane Abrha Asfaw
- Institute of Applied Geosciences, Technische Universität Darmstadt, Schnittspahn Straße 9, Darmstadt, 64287, Germany
| | - Kaori Sakaguchi-Söder
- Institute of Applied Geosciences, Technische Universität Darmstadt, Schnittspahn Straße 9, Darmstadt, 64287, Germany
- Institut IWAR, Technische Universität Darmstadt, Franziska-Braun Straße 7, Darmstadt, 64287, Germany
| | - Anat Bernstein
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, Ben-Gurion University of the Negev, Sde Boker Campus, Beer-Sheva, 84990, Israel
| | - Hagar Siebner
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, Ben-Gurion University of the Negev, Sde Boker Campus, Beer-Sheva, 84990, Israel
| | - Christoph Schüth
- Institute of Applied Geosciences, Technische Universität Darmstadt, Schnittspahn Straße 9, Darmstadt, 64287, Germany
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Zimmermann J, Halloran LJS, Hunkeler D. Tracking chlorinated contaminants in the subsurface using compound-specific chlorine isotope analysis: A review of principles, current challenges and applications. CHEMOSPHERE 2020; 244:125476. [PMID: 31830644 DOI: 10.1016/j.chemosphere.2019.125476] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 11/20/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Many chlorinated hydrocarbons have gained notoriety as persistent organic pollutants in the environment. Engineered and natural remediation efforts require a monitoring tool to track the progress of degradation processes. Compound-specific isotope analysis (CSIA) is a robust method to evaluate the origin and fate of contaminants in the environment and does not rely on concentration measurements. While carbon CSIA has established itself in the routine assessment of contaminated sites, studies incorporating chlorine isotopes have only recently become more common. Although some aspects of chlorine isotope analysis are more challenging than carbon isotope analysis, having additional isotopic data yields valuable information for contaminated site management. This review provides an overview of chlorine isotope fractionation of chlorinated contaminants in the subsurface by different processes and presents analytical techniques and unresolved challenges in chlorine isotope analysis. A summary of successful field applications illustrates the potential of using chlorine isotope data. Finally, approaches in modelling chlorine isotope fractionation due to degradation, diffusion, and sorption processes are discussed.
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Affiliation(s)
- Jeremy Zimmermann
- Centre for Hydrogeology and Geothermics, University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland.
| | - Landon J S Halloran
- Centre for Hydrogeology and Geothermics, University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics, University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland
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16
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Martin PR, Buchner D, Jochmann MA, Haderlein SB. Stable carbon isotope analysis of polyphosphonate complexing agents by anion chromatography coupled to isotope ratio mass spectrometry: method development and application. Anal Bioanal Chem 2019; 412:4827-4835. [PMID: 31813019 DOI: 10.1007/s00216-019-02251-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/23/2019] [Accepted: 10/29/2019] [Indexed: 11/30/2022]
Abstract
Compound-specific carbon isotope analysis (carbon CSIA) by liquid chromatography/isotope ratio mass spectrometry (LC-IRMS) is a novel and promising tool to elucidate the environmental fate of polar organic compounds such as polyphosphonates, strong complexing agents for di- and trivalent cations with growing commercial importance over the last decades. Here, we present a LC-IRMS method for the three widely used polyphosphonates 1-hydroxyethane 1,1-diphosphonate (HEDP), amino tris(methylenephosphonate) (ATMP), and ethylenediamine tetra(methylenephosphonate) (EDTMP). Separation of the analytes, as well as ATMP and its degradation products, was carried out on an anion exchange column under acidic conditions. Quantitative wet chemical oxidation inside the LC-IRMS interface to CO2 was achieved for all three investigated polyphosphonates at a comparatively low sodium persulfate concentration despite the described resilience of HEDP towards oxidative breakdown. The developed method has proven to be suitable for the determination of carbon isotope fractionation of ATMP transformation due to manganese-catalyzed reaction with molecular oxygen, as well as for equilibrium sorption of ATMP to goethite. A kinetic isotope effect was associated with the investigated reaction pathway, whereas no detectable isotope fractionation could be observed during sorption. Thus, CSIA is an appropriate technique to distinguish between sorption and degradation processes that contribute to a concentration decrease of ATMP in laboratory batch experiments. Our study highlights the potential of carbon CSIA by LC-IRMS to gain a process-based understanding of the fate of polyphosphonate complexing agents in environmental as well as technical systems.
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Affiliation(s)
- Philipp R Martin
- Center for Applied Geoscience (ZAG), Eberhard Karls University Tübingen, Hölderlinstr. 12, 72074, Tübingen, Germany
| | - Daniel Buchner
- Center for Applied Geoscience (ZAG), Eberhard Karls University Tübingen, Hölderlinstr. 12, 72074, Tübingen, Germany.
| | - Maik A Jochmann
- Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstr. 5, 45141, Essen, Germany
| | - Stefan B Haderlein
- Center for Applied Geoscience (ZAG), Eberhard Karls University Tübingen, Hölderlinstr. 12, 72074, Tübingen, Germany
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Ponsin V, Torrentó C, Lihl C, Elsner M, Hunkeler D. Compound-Specific Chlorine Isotope Analysis of the Herbicides Atrazine, Acetochlor, and Metolachlor. Anal Chem 2019; 91:14290-14298. [DOI: 10.1021/acs.analchem.9b02497] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Violaine Ponsin
- Centre of Hydrogeology and Geothermics (CHYN), University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Clara Torrentó
- Centre of Hydrogeology and Geothermics (CHYN), University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Christina Lihl
- Institute of Groundwater Ecology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich, 81377 Munich, Germany
| | - Daniel Hunkeler
- Centre of Hydrogeology and Geothermics (CHYN), University of Neuchâtel, 2000 Neuchâtel, Switzerland
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Torrentó C, Bakkour R, Glauser G, Melsbach A, Ponsin V, Hofstetter TB, Elsner M, Hunkeler D. Solid-phase extraction method for stable isotope analysis of pesticides from large volume environmental water samples. Analyst 2019; 144:2898-2908. [PMID: 30896686 DOI: 10.1039/c9an00160c] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Compound-specific isotope analysis (CSIA) is a valuable tool for assessing the fate of organic pollutants in the environment. However, the requirement of sufficient analyte mass for precise isotope ratio mass spectrometry combined with prevailing low environmental concentrations currently limits comprehensive applications to many micropollutants. Here, we evaluate the upscaling of solid-phase extraction (SPE) approaches for routine CSIA of herbicides. To cover a wide range of polarity, a SPE method with two sorbents (a hydrophobic hypercrosslinked sorbent and a hydrophilic sorbent) was developed. Extraction conditions, including the nature and volume of the elution solvent, the amount of sorbent and the solution pH, were optimized. Extractions of up to 10 L of agricultural drainage water (corresponding to up to 200 000-fold pre-concentration) were successfully performed for precise and sensitive carbon and nitrogen CSIA of the target herbicides atrazine, acetochlor, metolachlor and chloridazon, and metabolites desethylatrazine, desphenylchloridazon and 2,6-dichlorobenzamide in the sub-μg L-1-range. 13C/12C and 15N/14N ratios were measured by gas chromatography-isotope ratio mass spectrometry (GC/IRMS), except for desphenylchloridazon, for which liquid chromatography (LC/IRMS) and derivatization-GC/IRMS were used, respectively. The method validated in this study is an important step towards analyzing isotope ratios of pesticide mixtures in aquatic systems and holds great potential for multi-element CSIA applications to trace pesticide degradation in complex environments.
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Affiliation(s)
- Clara Torrentó
- Centre for Hydrogeology and Geothermics (CHYN), University of Neuchâtel, 2000 Neuchâtel, Switzerland.
| | - Rani Bakkour
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Gaétan Glauser
- Neuchâtel Platform of Analytical Chemistry (NPAC), University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - 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.
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Martin Elsner
- Helmholtz Zentrum München, Institute of Groundwater Ecology, 85764 Neuherberg, Germany and Technical University of Munich, Chair of Analytical Chemistry and Water Chemistry, 81377 Munich, Germany
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics (CHYN), University of Neuchâtel, 2000 Neuchâtel, Switzerland.
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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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Tobias HJ, Jones A, Spanjers C, Bowers L, Brenna JT. Low Temperature Catalytic Combustion Reactors for High Precision Carbon Isotope Measurements in Gas Chromatography Combustion Isotope Ratio Mass Spectrometry. Anal Chem 2019; 91:2901-2907. [DOI: 10.1021/acs.analchem.8b05043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Herbert J. Tobias
- Dell Pediatric Research Institute, Dell Medical School, University of Texas at Austin, 1400 Barbara Jordan Boulevard, Austin, Texas 78723, United States
| | - Andrew Jones
- Activated Research Company, 7561 Corporate Way, Eden Prairie, Minnesota 55344, United States
| | - Charlie Spanjers
- Activated Research Company, 7561 Corporate Way, Eden Prairie, Minnesota 55344, United States
| | - Larry Bowers
- LDBowers, LLC, Southern Pines, North Carolina 28387, United States
| | - J. Thomas Brenna
- Dell Pediatric Research Institute, Dell Medical School, University of Texas at Austin, 1400 Barbara Jordan Boulevard, Austin, Texas 78723, United States
- Department of Chemistry, College of Natural Sciences, University of Texas at Austin, Austin, Texas 78712-1224, United States
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21
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Leitner S, Reichenauer TG, Watzinger A. Impact of sorption processes on PCE concentrations in organohalide-respiring aquifer sediment samples. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 615:1061-1069. [PMID: 29751409 DOI: 10.1016/j.scitotenv.2017.09.225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 06/08/2023]
Abstract
The evaluation of groundwater contaminant e.g. tetrachloroethene (PCE) degradation processes requires complete quantification of and pathway analysis of the groundwater contaminant under investigation. For example the reduction of PCE concentrations in the groundwater by unknown dissolution and/or sorption processes will impede interpretation of the fate and behaviour of such contaminants. In the present study PCE dissolution and sorption processes during anaerobic microbial degradation of chlorinated ethenes were investigated. For this purpose, microcosms were prepared using sediment samples from a PCE-contaminated aquifer, which in previous studies had demonstrated anaerobic organohalide respiration of PCE. Solid/water distribution coefficients (kd) of PCE were determined and validated by loss-on-ignition (LOI) and PCE sorption experiments. The determined kd magnitudes indicated methodological congruency, yielding values for sediment samples within a range of 1.15±0.02 to 5.93±0.34L·kg-1. The microcosm experiment showed lower PCE concentrations than expected, based on spiked PCE and observed anaerobic microbial degradation processes. Nevertheless the amount of PCE spike added was completely recovered albeit in the form of lower chlorinated metabolites. A delay due to dissolution processes was not responsible for this phenomenon. Sorption to sediments could only partially explain the reduction of PCE in the water phase. Accordingly, the results point to reversible sorption processes of PCE, possibly onto bacterial cell compartments and/or exopolymeric substances.
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Affiliation(s)
- Simon Leitner
- AIT Austrian Institute of Technology GmbH, Center for Energy, Environmental Resources and Technologies, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
| | - Thomas G Reichenauer
- AIT Austrian Institute of Technology GmbH, Center for Energy, Environmental Resources and Technologies, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
| | - Andrea Watzinger
- AIT Austrian Institute of Technology GmbH, Center for Energy, Environmental Resources and Technologies, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria.
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22
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Willach S, Lutze HV, Eckey K, Löppenberg K, Lüling M, Wolbert JB, Kujawinski DM, Jochmann MA, Karst U, Schmidt TC. Direct Photolysis of Sulfamethoxazole Using Various Irradiation Sources and Wavelength Ranges-Insights from Degradation Product Analysis and Compound-Specific Stable Isotope Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:1225-1233. [PMID: 29303258 DOI: 10.1021/acs.est.7b04744] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The environmental micropollutant sulfamethoxazole (SMX) is susceptible to phototransformation by sunlight and UV-C light which is used for water disinfection. Depending on the environmental pH conditions SMX may be present as neutral or anionic species. This study systematically investigates the phototransformation of these two relevant SMX species using four different irradiation scenarios, i.e., a low, medium, and high pressure Hg lamp and simulated sunlight. The observed phototransformation kinetics are complemented by data from compound-specific stable isotope and transformation product analysis using isotope-ratio and high-resolution mass spectrometry (HRMS). Observed phototransformation kinetics were faster for the neutral than for the anionic SMX species (from 3.4 (LP lamp) up to 6.6 (HP lamp) times). Furthermore, four phototransformation products (with m/z 189, 202, 242, and 260) were detected by HRMS that have not yet been described for direct photolysis of SMX. Isotopic fractionation occurred only if UV-B and UV-A wavelengths prevailed in the emitted irradiation and was most pronounced for the neutral species with simulated sunlight (εC = -4.8 ± 0.1 ‰). Phototransformation of SMX with UV-C light did not cause significant isotopic fractionation. Consequently, it was possible to differentiate sunlight and UV-C light induced phototransformation of SMX. Thus, CSIA might be implemented to trace back wastewater point sources or to assess natural attenuation of SMX by sunlight photolysis. In contrast to the wavelength range, pH-dependent speciation of SMX hardly impacted isotopic fractionation.
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Affiliation(s)
- Sarah Willach
- University of Duisburg-Essen , Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
| | - Holger V Lutze
- University of Duisburg-Essen , Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
- IWW Water Centre , Moritzstraße 26, D-45476 Muelheim an der Ruhr, Germany
- University of Duisburg-Essen , Centre for Water and Environmental Research (ZWU), Universitaetsstraße 5 D-45141 Essen, Germany
| | - Kevin Eckey
- University of Muenster , Institute of Inorganic and Analytical Chemistry, Corrensstraße 28-30 D-48149, Muenster, Germany
| | - Katja Löppenberg
- University of Duisburg-Essen , Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
| | - Michelle Lüling
- University of Duisburg-Essen , Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
| | - Jens-Benjamin Wolbert
- University of Duisburg-Essen , Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
| | - Dorothea M Kujawinski
- University of Duisburg-Essen , Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
| | - Maik A Jochmann
- University of Duisburg-Essen , Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
- University of Duisburg-Essen , Centre for Water and Environmental Research (ZWU), Universitaetsstraße 5 D-45141 Essen, Germany
| | - Uwe Karst
- University of Muenster , Institute of Inorganic and Analytical Chemistry, Corrensstraße 28-30 D-48149, Muenster, Germany
| | - Torsten C Schmidt
- University of Duisburg-Essen , Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
- IWW Water Centre , Moritzstraße 26, D-45476 Muelheim an der Ruhr, Germany
- University of Duisburg-Essen , Centre for Water and Environmental Research (ZWU), Universitaetsstraße 5 D-45141 Essen, Germany
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23
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Spahr S, von Gunten U, Hofstetter TB. Carbon, Hydrogen, and Nitrogen Isotope Fractionation Trends in N-Nitrosodimethylamine Reflect the Formation Pathway during Chloramination of Tertiary Amines. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:13170-13179. [PMID: 29032675 DOI: 10.1021/acs.est.7b03919] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Assessing the precursors and reactions leading to the carcinogenic N-nitrosodimethylamine (NDMA) during drinking water disinfection is a major challenge. Here, we investigate whether changes of 13C/12C, 2H/1H, and 15N/14N ratios of NDMA give rise to isotope fractionation trends that can be used to infer NDMA formation pathways. We carried out compound-specific isotope analysis (CSIA) of NDMA during chloramination of four tertiary amines that produce NDMA at high yields, namely ranitidine, 5-(dimethylaminomethyl)furfuryl alcohol, N,N-dimethylthiophene-2-methylamine, and N,N-dimethylbenzylamine. Carbon and hydrogen isotope ratios of NDMA function as fingerprints of the N(CH3)2 moiety and exhibit only minor isotope fractionation during the disinfection process. Nitrogen isotope ratios showed that NH2Cl is the source of the N atom of the nitroso group. The large enrichment of 15N in NDMA was indicative of the isotope effects pertinent to bond-cleavage and bond-formation reactions during chloramination of the tertiary amines. Correlation of δ15N versus δ13C values of NDMA resulted in trend lines that were not affected by the type of tertiary amine and treatment conditions, suggesting that the observed C and N isotope fractionation in NDMA may be diagnostic for NDMA precursors and formation pathways during chloramination.
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Affiliation(s)
- Stephanie Spahr
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Federale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Federale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich , CH-8092 Zürich, Switzerland
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich , CH-8092 Zürich, Switzerland
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24
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Leitner S, Berger H, Gorfer M, Reichenauer TG, Watzinger A. Isotopic effects of PCE induced by organohalide-respiring bacteria. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:24803-24815. [PMID: 28913587 DOI: 10.1007/s11356-017-0075-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Reductive dechlorination performed by organohalide-respiring bacteria (OHRB) enables the complete detoxification of certain emerging groundwater pollutants such as perchloroethene (PCE). Environmental samples from a contaminated site incubated in a lab-scale microcosm (MC) study enable documentation of such reductive dechlorination processes. As compound-specific isotope analysis is used to monitor PCE degradation processes, nucleic acid analysis-like 16S-rDNA analysis-can be used to determine the key OHRB that are present. This study applied both methods to laboratory MCs prepared from environmental samples to investigate OHRB-specific isotope enrichment at PCE dechlorination. This method linkage can enhance the understanding of isotope enrichment patterns of distinct OHRB, which further contribute to more accurate evaluation, characterisation and prospection of natural attenuation processes. Results identified three known OHRB genera (Dehalogenimonas, Desulfuromonas, Geobacter) in diverse abundance within MCs. One species of Dehalogenimonas was potentially involved in complete reductive dechlorination of PCE to ethene. Furthermore, the isotopic effects of PCE degradation were clustered and two isotope enrichment factors (ε) (- 11.6‰, - 1.7‰) were obtained. Notably, ε values were independent of degradation rates and kinetics, but did reflect the genera of the dechlorinating OHRB.
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Affiliation(s)
- Simon Leitner
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Harald Berger
- AIT Austrian Institute of Technology GmbH, Health & Environment Department, Bioresources, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Markus Gorfer
- AIT Austrian Institute of Technology GmbH, Health & Environment Department, Bioresources, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Thomas G Reichenauer
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Andrea Watzinger
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria.
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Schulte M, Jochmann MA, Gehrke T, Thom A, Ricken T, Denecke M, Schmidt TC. Characterization of methane oxidation in a simulated landfill cover system by comparing molecular and stable isotope mass balances. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 69:281-288. [PMID: 28811145 DOI: 10.1016/j.wasman.2017.07.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
Biological methane oxidation may be regarded as a method of aftercare treatment for landfills to reduce climate relevant methane emissions. It is of social and economic interest to estimate the behavior of bacterial methane oxidation in aged landfill covers due to an adequate long-term treatment of the gas emissions. Different approaches assessing methane oxidation in laboratory column studies have been investigated by other authors recently. However, this work represents the first study in which three independent approaches, ((i) mass balance, (ii) stable isotope analysis, and (iii) stoichiometric balance of product (CO2) and reactant (CH4) by CO2/CH4-ratio) have been compared for the estimation of the biodegradation by a robust statistical validation on a rectangular, wide soil column. Additionally, an evaluation by thermal imaging as a potential technique for the localization of the active zone of bacterial methane oxidation has been addressed in connection with stable isotope analysis and CO2/CH4-ratios. Although landfills can be considered as open systems the results for stable isotope analysis based on a closed system correlated better with the mass balance than calculations based on an open system. CO2/CH4-ratios were also in good agreement with mass balance. In general, highest values for biodegradation were determined from mass balance, followed by CO2/CH4-ratio, and stable isotope analysis. The investigated topsoil proved to be very suitable as a potential cover layer by removing up to 99% of methane for CH4 loads of 35-65gm-2d-1 that are typical in the aftercare phase of landfills. Finally, data from stable isotope analysis and the CO2/CH4-ratios were used to trace microbial activity within the reactor system. It was shown that methane consumption and temperature increase, as a cause of high microbial activity, correlated very well.
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Affiliation(s)
- Marcel Schulte
- Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - Maik A Jochmann
- Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany.
| | - Tobias Gehrke
- Department of Water and Waste Management, University of Duisburg-Essen, Universitätsstr. 15, 45141 Essen, Germany
| | - Andrea Thom
- Chair of Mechanics, Structural Analysis, Dynamics, Dortmund Technical University, August-Schmidt-Str. 6, 44227 Dortmund, Germany
| | - Tim Ricken
- Chair of Mechanics, Structural Analysis, Dynamics, Dortmund Technical University, August-Schmidt-Str. 6, 44227 Dortmund, Germany
| | - Martin Denecke
- Department of Water and Waste Management, University of Duisburg-Essen, Universitätsstr. 15, 45141 Essen, Germany
| | - Torsten C Schmidt
- Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
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26
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Leitner S, Reichenauer TG, Watzinger A. Determination of carbon isotope enrichment factors of cis-dichloroethene after precursor amendment. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1699-1708. [PMID: 28805260 DOI: 10.1002/rcm.7957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/26/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Bacterial reductive dechlorination of the groundwater contaminant tetrachloroethene (PCE) involves the formation of lower chlorinated metabolites. Metabolites can be instantaneously formed and consumed in this sequential process; quantification and validation of their isotopic effects conventionally rely on separate laboratory microcosm studies. Here, we present an evaluation method enabling the determination of the carbon isotope enrichment factor (ε) for the intermediate cis-dichloroethene (cis-DCE) by a single laboratory microcosm study initially amending the precursor PCE only. METHODS Environmental samples harboring organohalide-respiring bacteria were incubated under anaerobic conditions and then successively and repeatedly amended with PCE and cis-DCE in two separate laboratory microcosm studies. Reductive dechlorination was monitored by analyzing liquid samples using Purge-and-Trap gas chromatography isotope ratio mass spectrometry GC/MS-C/IRMS. The prerequisites of the presented evaluation method are mass and δ-value balancing. The evaluation method was validated by agglomerative hierarchical classification of Rayleigh plot data points. RESULTS The sample-sensitive range of εcis-DCE extended from -10.6 ± 0.2‰ to -26.8 ± 0.6‰ (R2 ≥98%). The maximum standard deviations of εcis-DCE were ±1.8‰ for single microcosms, ±1.8‰ for replicates and ±1.0‰ for the compiled replicate data of PCE and cis-DCE amendments. A linear regression of the εcis-DCE for replicates obtained by each amendment study showed a slope of 95% (5 of the 7 data points are within a 95% confidence interval), demonstrating factor congruency and the practicability of the evaluation method. CONCLUSIONS We found metabolite degradation and formation to be sequential but also stepwise during bacterial reductive dechlorination. The stepwise phases of the degradation of the intermediate eliminate the impact of instantaneous precursor degradation. These stepwise sections were used to determine εcis-DCE -values. Our results showed the validity of εcis-DCE -values over a wide range at initial precursor degradation (PCE). The presented evaluation method could substantially decrease lab costs for microcosm studies designed for εcis-DCE determinations. Moreover, the results indicated that the evaluation method can be applied to other PCE-metabolites.
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Affiliation(s)
- Simon Leitner
- Center for Energy, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria
| | - Thomas G Reichenauer
- Center for Energy, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria
| | - Andrea Watzinger
- Center for Energy, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria
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27
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Willach S, Lutze HV, Eckey K, Löppenberg K, Lüling M, Terhalle J, Wolbert JB, Jochmann MA, Karst U, Schmidt TC. Degradation of sulfamethoxazole using ozone and chlorine dioxide - Compound-specific stable isotope analysis, transformation product analysis and mechanistic aspects. WATER RESEARCH 2017; 122:280-289. [PMID: 28609731 DOI: 10.1016/j.watres.2017.06.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/29/2017] [Accepted: 06/01/2017] [Indexed: 06/07/2023]
Abstract
The sulfonamide antibiotic sulfamethoxazole (SMX) is a widely detected micropollutant in surface and groundwaters. Oxidative treatment with e.g. ozone or chlorine dioxide is regularly applied for disinfection purposes at the same time exhibiting a high potential for removal of micropollutants. Especially for nitrogen containing compounds such as SMX, the related reaction mechanisms are largely unknown. In this study, we systematically investigated reaction stoichiometry, product formation and reaction mechanisms in reactions of SMX with ozone and chlorine dioxide. To this end, the neutral and anionic SMX species, which may occur at typical pH-values of water treatment were studied. Two moles of chlorine dioxide and approximately three moles of ozone were consumed per mole SMX degraded. Oxidation of SMX with ozone and chlorine dioxide leads in both cases to six major transformation products (TPs) as revealed by high-resolution mass spectrometry (HRMS). Tentatively formulated TP structures from other studies could partly be confirmed by compound-specific stable isotope analysis (CSIA). However, for one TP, a hydroxylated SMX, it was not possible by HRMS alone to identify whether hydroxylation occurred at the aromatic ring, as suggested in literature before, or at the anilinic nitrogen. By means of CSIA and an analytical standard it was possible to identify sulfamethoxazole hydroxylamine unequivocally as one of the TPs of the reaction of SMX with ozone as well as with chlorine dioxide. H-abstraction and electron transfer at the anilinic nitrogen are suggested as likely initial reactions of ozone and chlorine dioxide, respectively, leading to its formation. Oxidation of anionic SMX with ozone did not show any significant isotopic fractionation whereas the other reactions studied resulted in a significant carbon isotope fractionation.
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Affiliation(s)
- Sarah Willach
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstr. 5, D-45141 Essen, Germany
| | - Holger V Lutze
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstr. 5, D-45141 Essen, Germany; IWW Water Centre, Moritzstr. 26, D-45476 Muelheim an der Ruhr, Germany; Centre for Water and Environmental Research (ZWU), Universitaetsstr. 5, D-45141 Essen, Germany
| | - Kevin Eckey
- University of Muenster, Institute of Inorganic and Analytical Chemistry, Corrensstr. 30, D-48149 Muenster, Germany
| | - Katja Löppenberg
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstr. 5, D-45141 Essen, Germany
| | - Michelle Lüling
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstr. 5, D-45141 Essen, Germany
| | - Jens Terhalle
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstr. 5, D-45141 Essen, Germany
| | - Jens-Benjamin Wolbert
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstr. 5, D-45141 Essen, Germany
| | - Maik A Jochmann
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstr. 5, D-45141 Essen, Germany; Centre for Water and Environmental Research (ZWU), Universitaetsstr. 5, D-45141 Essen, Germany
| | - Uwe Karst
- University of Muenster, Institute of Inorganic and Analytical Chemistry, Corrensstr. 30, D-48149 Muenster, Germany
| | - Torsten C Schmidt
- University of Duisburg-Essen, Faculty of Chemistry, Instrumental Analytical Chemistry, Universitaetsstr. 5, D-45141 Essen, Germany; IWW Water Centre, Moritzstr. 26, D-45476 Muelheim an der Ruhr, Germany; Centre for Water and Environmental Research (ZWU), Universitaetsstr. 5, D-45141 Essen, Germany.
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28
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Optimization of the solvent-based dissolution method to sample volatile organic compound vapors for compound-specific isotope analysis. J Chromatogr A 2017; 1520:23-34. [DOI: 10.1016/j.chroma.2017.08.059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 06/27/2017] [Accepted: 08/20/2017] [Indexed: 11/22/2022]
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29
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Pati SG, Kohler HPE, Hofstetter TB. Characterization of Substrate, Cosubstrate, and Product Isotope Effects Associated With Enzymatic Oxygenations of Organic Compounds Based on Compound-Specific Isotope Analysis. Methods Enzymol 2017; 596:291-329. [PMID: 28911775 DOI: 10.1016/bs.mie.2017.06.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Enzymatic oxygenations are among the most important biodegradation and detoxification reactions of organic pollutants. In the environment, however, such natural attenuation processes are extremely difficult to monitor. Changes of stable isotope ratios of aromatic pollutants at natural isotopic abundances serve as proxies for isotope effects associated with oxygenation reactions. Such isotope fractionations offer new avenues for revealing the pathway and extent of pollutant transformation and provide new insights into the mechanisms of catalysis by Rieske non-heme ferrous iron oxygenases. Based on compound-specific C, H, N, and O isotope analysis, we present a comprehensive methodology with which isotope effects can be derived from the isotope fractionation measured in substrates, the cosubstrate O2, and organic oxygenation products. We use dioxygenation of nitrobenzene and 2-nitrotoluene by nitrobenzene dioxygenase as illustrative examples to introduce different mathematical procedures for deriving apparent substrate and product isotope effects. We present two experimental approaches to control reactant and product turnover for isotope fractionation analysis in experimental systems containing purified enzymes, E. coli clones, and pure strains of environmental microorganisms. Finally, we present instrumental procedures and sample treatment instructions for analysis of C, H, and N isotope analysis in organic compounds and O isotope analysis in aqueous O2 by gas and liquid chromatography coupled to isotope ratio mass spectrometry.
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Affiliation(s)
- Sarah G Pati
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, Zürich, Switzerland
| | - Hans-Peter E Kohler
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, Zürich, Switzerland.
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30
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Wijker RS, Zeyer J, Hofstetter TB. Isotope fractionation associated with the simultaneous biodegradation of multiple nitrophenol isomers by Pseudomonas putida B2. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2017; 19:775-784. [PMID: 28470308 DOI: 10.1039/c6em00668j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Quantifying the extent of biodegradation of nitroaromatic compounds (NACs) in contaminated soils and sediments is challenging because of competing oxidative and reductive reaction pathways. We have previously shown that the stable isotope fractionation of NACs reveals the routes of degradation even if it is simultaneously caused by different bacteria. However, it is unclear whether compound-specific isotope analysis (CSIA) can be applied in situations where multiple pollutants are biodegraded by only one microorganism under multi-substrate conditions. Here we examined the C and N isotope fractionation of 2-nitrophenol (2-NP) and 3-nitrophenol (3-NP) during biodegradation by Pseudomonas putida B2 through monooxygenation and partial reductive pathways, respectively, in the presence of single substrates vs. binary substrate mixtures. Laboratory experiments showed that the reduction of 3-NP by Pseudomonas putida B2 is associated with large N and minor C isotope fractionation with C and N isotope enrichment factors, εC and εN, of -0.3 ± 0.1‰ and -22 ± 0.2‰, respectively. The opposite isotope fractionation trends were found for 2-NP monooxygenation. In the simultaneous presence of 2-NP and 3-NP, 2-NP is biodegraded at identical rate constants and εC and εN values (-1.0 ± 0.1‰ and -1.3 ± 0.2‰) to those found for the monooxygenation of 2-NP in single substrate experiments. While the pathway and N isotope fractionation of 3-NP reduction (εN = -24 ± 1.1‰) are independent of the presence of 2-NP, intermediates of 2-NP monooxygenation interfere with 3-NP reduction. Because neither pH, substrate uptake, nor aromatic substituents affected the kinetic isotope effects of nitrophenol biodegradation, our study illustrates that CSIA provides robust scientific evidence for the assessment of natural attenuation processes.
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Affiliation(s)
- Reto S Wijker
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, Zürich, Switzerland.
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Xu BS, Lollar BS, Passeport E, Sleep BE. Diffusion related isotopic fractionation effects with one-dimensional advective-dispersive transport. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 550:200-208. [PMID: 26815297 DOI: 10.1016/j.scitotenv.2016.01.114] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 01/18/2016] [Accepted: 01/18/2016] [Indexed: 06/05/2023]
Abstract
Aqueous phase diffusion-related isotope fractionation (DRIF) for carbon isotopes was investigated for common groundwater contaminants in systems in which transport could be considered to be one-dimensional. This paper focuses not only on theoretically observable DRIF effects in these systems but introduces the important concept of constraining "observable" DRIF based on constraints imposed by the scale of measurements in the field, and on standard limits of detection and analytical uncertainty. Specifically, constraints for the detection of DRIF were determined in terms of the diffusive fractionation factor, the initial concentration of contaminants (C0), the method detection limit (MDL) for isotopic analysis, the transport time, and the ratio of the longitudinal mechanical dispersion coefficient to effective molecular diffusion coefficient (Dmech/Deff). The results allow a determination of field conditions under which DRIF may be an important factor in the use of stable carbon isotope measurements for evaluation of contaminant transport and transformation for one-dimensional advective-dispersive transport. This study demonstrates that for diffusion-dominated transport of BTEX, MTBE, and chlorinated ethenes, DRIF effects are only detectable for the smaller molar mass compounds such as vinyl chloride for C0/MDL ratios of 50 or higher. Much larger C0/MDL ratios, corresponding to higher source concentrations or lower detection limits, are necessary for DRIF to be detectable for the higher molar mass compounds. The distance over which DRIF is observable for VC is small (less than 1m) for a relatively young diffusive plume (<100years), and DRIF will not easily be detected by using the conventional sampling approach with "typical" well spacing (at least several meters). With contaminant transport by advection, mechanical dispersion, and molecular diffusion this study suggests that in field sites where Dmech/Deff is larger than 10, DRIF effects will likely not be observable for common groundwater contaminants. Importantly, under most field conditions, Dmech/Deff≥10 is usually satisfied in the longitudinal direction, suggesting that DRIF is not likely to be observable in most groundwater systems in which contaminant transport is predominantly one-dimensional. Given the importance in the MDL it is recommended that MDL should always be explicitly reported in both modeling and field studies.
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Affiliation(s)
- Bruce S Xu
- Civil Engineering Department, University of Toronto, 35 St George Street, Toronto, ON M5S 1A4, Canada
| | - Barbara Sherwood Lollar
- Earth Sciences Department, University of Toronto, 22 Russell Street, Toronto, ON M5S 3B1, Canada
| | - Elodie Passeport
- Civil Engineering Department, University of Toronto, 35 St George Street, Toronto, ON M5S 1A4, Canada; Chemical Engineering and Applied Chemistry Department, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada
| | - Brent E Sleep
- Civil Engineering Department, University of Toronto, 35 St George Street, Toronto, ON M5S 1A4, Canada.
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Wei X, Gilevska T, Wetzig F, Dorer C, Richnow HH, Vogt C. Characterization of phenol and cresol biodegradation by compound-specific stable isotope analysis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 210:166-73. [PMID: 26716730 DOI: 10.1016/j.envpol.2015.11.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/21/2015] [Accepted: 11/02/2015] [Indexed: 05/06/2023]
Abstract
Microbial degradation of phenol and cresols can occur under oxic and anoxic conditions by different degradation pathways. One recent technique to take insight into reaction mechanisms is compound-specific isotope analysis (CSIA). While enzymes and reaction mechanisms of several degradation pathways have been characterized in (bio)chemical studies, associated isotope fractionation patterns have been rarely reported, possibly due to constraints in current analytical methods. In this study, carbon enrichment factors and apparent kinetic isotope effects (AKIEc) of the initial steps of different aerobic and anaerobic phenol and cresols degradation pathways were analyzed by isotope ratio mass spectrometry connected with liquid chromatography (LC-IRMS). Significant isotope fractionation was detected for aerobic ring hydroxylation, anoxic side chain hydroxylation, and anoxic fumarate addition, while anoxic carboxylation reactions produced small and inconsistent fractionation. The results suggest that several microbial degradation pathways of phenol and cresols are detectable in the environment by CSIA.
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Affiliation(s)
- Xi Wei
- Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany; Friedrich Schiller University Jena, Institute for Microbiology, Department of Applied and Ecological Microbiology, Jena, Germany
| | - Tetyana Gilevska
- Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany
| | - Felix Wetzig
- Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany; Friedrich Schiller University Jena, Faculty of Chemistry and Earth Science, Jena, Germany
| | - Conrad Dorer
- Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany; University of Freiburg, Faculty of Biology, Schänzlestrasse 1, Freiburg, Germany
| | - Hans-Hermann Richnow
- Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany
| | - Carsten Vogt
- Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany.
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33
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Blessing M, Jochmann MA, Haderlein SB, Schmidt TC. Optimization of a large-volume injection method for compound-specific isotope analysis of polycyclic aromatic compounds at trace concentrations. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:2349-2360. [PMID: 26563706 DOI: 10.1002/rcm.7389] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/02/2015] [Accepted: 09/07/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE Compound-specific isotope analysis (CSIA) of persistent organic contaminants can be used for source apportioning in the environment if appropriate sensitivity can be achieved. This paper describes the optimization and validation of a sensitive analytical approach for the determination of the carbon isotope composition of semi-volatile organic compounds, such as polycyclic aromatic hydrocarbons (PAHs). METHODS Analyses are based on the introduction of up to 150 μL of organic extracts by means of programmed temperature vaporization-large-volume injection combined with gas chromatography coupled to isotope ratio mass spectrometry (PTV-LVI-GC/IRMS). To allow for the analysis of more volatile, low-molecular-weight PAHs, the PTV injector was equipped with a sub-ambient/cryogenic cooling. Accuracy, precision, linearity and determination limits for application in isotope analysis were evaluated for a set of individual PAHs ranging from two- to five-ring molecular structures. The method was exemplified by determining the δ(13) C values of individual PAHs in soil samples in a source apportionment study at a contaminated site. RESULTS The choice of PTV injection parameters is crucial to prevent isotope fractionation during injection and largely depends on the analytes to be determined. The observed isotope fractionation effect on semi-volatiles depends on the applied solvent and injection temperature and demonstrates the importance of performing appropriate tests with given PTV parameters for each of the compounds of interest. The proposed PTV-LVI-GC/IRMS method allows the carbon isotope ratio (δ(13) C value) of individual PAHs to be determined accurately and precisely at concentrations of 0.04-0.1 ng μL(-1) even for volatile PAHs such as naphthalene or acenaphthene. CONCLUSIONS LVI with PTV injector cooling allows for the isotopic analysis of volatile and semi-volatile PAHs at trace concentrations, thus considerably expanding the applicability of CSIA in environmental studies.
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Affiliation(s)
- Michaela Blessing
- BRGM, LAB/ISO, 3 avenue Claude Guillemin, BP 36009, F-45060, Orléans cedex 2, France
| | - Maik A Jochmann
- Instrumental Analytical Chemistry, University Duisburg-Essen, Universitätsstr. 5, D-45141, Essen, Germany
| | - Stefan B Haderlein
- Center for Applied Geoscience (ZAG), Eberhard Karls University Tübingen, Hölderlinstr. 12, D-72076, Tübingen, Germany
| | - Torsten C Schmidt
- Instrumental Analytical Chemistry, University Duisburg-Essen, Universitätsstr. 5, D-45141, Essen, Germany
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34
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Ratti M, Canonica S, McNeill K, Bolotin J, Hofstetter TB. Isotope Fractionation Associated with the Indirect Photolysis of Substituted Anilines in Aqueous Solution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:12766-12773. [PMID: 26418612 DOI: 10.1021/acs.est.5b03119] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Organic micropollutants containing aniline substructures are susceptible to different light-induced transformation processes in aquatic environments and water treatment operations. Here, we investigated the magnitude and variability of C and N isotope fractionation during the indirect phototransformation of four para-substituted anilines in aerated aqueous solutions. The model photosensitizers, namely 9,10-anthraquinone-1,5-disulfonate and methylene blue, were used as surrogates for dissolved organic matter chromophores generating excited triplet states in sunlit surface waters. The transformation of aniline, 4-CH3-, 4-OCH3-, and 4-Cl-aniline by excited triplet states of the photosensitizers was associated with inverse and normal N isotope fractionation, whereas C isotope fractionation was negligible. The apparent 15N kinetic isotope effects (AKIE) were almost identical for both photosensitizers, increased from 0.9958±0.0013 for 4-OCH3-aniline to 1.0035±0.0006 for 4-Cl-aniline, and correlated well with the electron donating properties of the substituent. N isotope fractionation is pH-dependent in that H+ exchange reactions dominate below and N atom oxidation processes above the pKa value of the substituted aniline's conjugate acid. Correlations of C and N isotope fractionation for indirect phototransformation were different from those determined previously for the direct photolysis of chloroanilines and offer new opportunities to distinguish between abiotic degradation pathways.
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Affiliation(s)
- Marco Ratti
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
| | - Silvio Canonica
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
| | - Kristopher McNeill
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
| | - Jakov Bolotin
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich , CH-8092 Zürich, Switzerland
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35
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Ratti M, Canonica S, McNeill K, Erickson PR, Bolotin J, Hofstetter TB. Isotope fractionation associated with the direct photolysis of 4-chloroaniline. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:4263-4273. [PMID: 25719866 DOI: 10.1021/es505784a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Compound-specific isotope analysis is a useful approach to track transformations of many organic soil and water pollutants. Applications of CSIA to characterize photochemical processes, however, have hardly been explored. In this work, we systematically studied C and N isotope fractionation associated with the direct photolysis of 4-Cl-aniline used as a model compound for organic micropollutants that are known to degrade via photochemical processes. Laboratory experiments were carried out at an irradiation wavelength of 254 nm over the pH range 2.0 to 9.0 as well as in the presence of Cs(+) as a quencher of excited singlet 4-Cl-aniline at pH 7.0 and 9.0. We observed considerable variation of C and N isotope enrichment factors, ϵC and ϵN, between -1.2 ± 0.2‰ to -2.7 ± 0.2‰ for C and -0.6 ± 0.2‰ to -9.1 ± 1.6‰ for N, respectively, which could not be explained by the speciation of 4-Cl-aniline alone. In the presence of 1 M Cs(+), we found a marked increase of apparent (13)C-kinetic isotope effects ((13)C-AKIE) and decrease of 4-Cl-aniline fluorescence lifetimes. Our data suggest that variations of C and N isotope fractionation originate from heterolytic dechlorination of excited triplet and singlet states of 4-Cl-aniline. Linear correlations of (13)C-AKIE vs (15)N-AKIE were distinctly different for these two reaction pathways and may be explored further for the identification of photolytic aromatic dechlorination reactions.
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Affiliation(s)
- Marco Ratti
- †Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
- ‡Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, CH-8092 Zürich, Switzerland
| | - Silvio Canonica
- †Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Kristopher McNeill
- ‡Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, CH-8092 Zürich, Switzerland
| | - Paul R Erickson
- ‡Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, CH-8092 Zürich, Switzerland
| | - Jakov Bolotin
- †Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Thomas B Hofstetter
- †Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
- ‡Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, CH-8092 Zürich, Switzerland
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36
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Spahr S, Bolotin J, Schleucher J, Ehlers I, von Gunten U, Hofstetter TB. Compound-Specific Carbon, Nitrogen, and Hydrogen Isotope Analysis of N-Nitrosodimethylamine in Aqueous Solutions. Anal Chem 2015; 87:2916-24. [DOI: 10.1021/ac5044169] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stephanie Spahr
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
- School
of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jakov Bolotin
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Jürgen Schleucher
- Umeå University, Department of Medical Biochemistry
and Biophysics, S-90187 Umeå, Sweden
| | - Ina Ehlers
- Umeå University, Department of Medical Biochemistry
and Biophysics, S-90187 Umeå, Sweden
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
- School
of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Institute
of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland
| | - Thomas B. Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
- Institute
of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092 Zürich, Switzerland
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Herrero-Martín S, Nijenhuis I, Richnow HH, Gehre M. Coupling of a Headspace Autosampler with a Programmed Temperature Vaporizer for Stable Carbon and Hydrogen Isotope Analysis of Volatile Organic Compounds at Microgram per Liter Concentrations. Anal Chem 2015; 87:951-9. [DOI: 10.1021/ac503229e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sara Herrero-Martín
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Hans H. Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Matthias Gehre
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
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Pati SG, Kohler HPE, Bolotin J, Parales RE, Hofstetter TB. Isotope effects of enzymatic dioxygenation of nitrobenzene and 2-nitrotoluene by nitrobenzene dioxygenase. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:10750-10759. [PMID: 25101486 DOI: 10.1021/es5028844] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Oxygenation of aromatic rings is a frequent initial step in the biodegradation of persistent contaminants, and the accompanying isotope fractionation is increasingly used to assess the extent of transformation in the environment. Here, we systematically investigated the dioxygenation of two nitroaromatic compounds (nitrobenzene and 2-nitrotoluene) by nitrobenzene dioxygenase (NBDO) to obtain insights into the factors governing its C, H, and N isotope fractionation. Experiments were carried out at different levels of biological complexity from whole bacterial cells to pure enzyme. C, H, and N isotope enrichment factors and kinetic isotope effects (KIEs) were derived from the compound-specific isotope analysis of nitroarenes, whereas C isotope fractionation was also quantified in the oxygenated reaction products. Dioxygenation of nitrobenzene to catechol and 2-nitrotoluene to 3-methylcatechol showed large C isotope enrichment factors, ϵC, of -4.1 ± 0.2‰ and -2.5 ± 0.2‰, respectively, and was observed consistently in the substrates and dioxygenation products. ϵH- and ϵN-values were smaller, that is -5.7 ± 1.3‰ and -1.0 ± 0.3‰, respectively. C isotope fractionation was also identical in experiments with whole bacterial cells and pure enzymes. The corresponding (13)C-KIEs for the dioxygenation of nitrobenzene and 2-nitrotoluene were 1.025 ± 0.001 and 1.018 ± 0.001 and suggest a moderate substrate specificity. Our study illustrates that dioxygenation of nitroaromatic contaminants exhibits a large C isotope fractionation, which is not masked by substrate transport and uptake processes and larger than dioxygenation of other aromatic hydrocarbons.
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Affiliation(s)
- Sarah G Pati
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
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Ivdra N, Herrero-Martín S, Fischer A. Validation of user- and environmentally friendly extraction and clean-up methods for compound-specific stable carbon isotope analysis of organochlorine pesticides and their metabolites in soils. J Chromatogr A 2014; 1355:36-45. [DOI: 10.1016/j.chroma.2014.06.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 06/02/2014] [Accepted: 06/03/2014] [Indexed: 11/28/2022]
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40
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Zhang L, Thevis M, Piper T, Jochmann MA, Wolbert JB, Kujawinski DM, Wiese S, Teutenberg T, Schmidt TC. Carbon Isotope Ratio Analysis of Steroids by High-Temperature Liquid Chromatography-Isotope Ratio Mass Spectrometry. Anal Chem 2014; 86:2297-302. [DOI: 10.1021/ac403353x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lijun Zhang
- Instrumental
Analytical Chemistry, University Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - Mario Thevis
- Institute
of Biochemistry,
Center for Preventive Doping Research, German Sport University Cologne, Am Sportpark
Muengersdorf 6, 50933 Cologne, Germany
| | - Thomas Piper
- Institute
of Biochemistry,
Center for Preventive Doping Research, German Sport University Cologne, Am Sportpark
Muengersdorf 6, 50933 Cologne, Germany
| | - Maik A. Jochmann
- Instrumental
Analytical Chemistry, University Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - J. Benjamin Wolbert
- Instrumental
Analytical Chemistry, University Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - Dorothea M. Kujawinski
- Instrumental
Analytical Chemistry, University Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - Steffen Wiese
- Institute of Energy and Environmental Technology e.V., (IUTA), Bliersheimer Strasse 60, 47229 Duisburg, Germany
| | - Thorsten Teutenberg
- Institute of Energy and Environmental Technology e.V., (IUTA), Bliersheimer Strasse 60, 47229 Duisburg, Germany
| | - Torsten C. Schmidt
- Instrumental
Analytical Chemistry, University Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
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Buczyńska AJ, Geypens B, Van Grieken R, De Wael K. Large-volume injection combined with gas chromatography/isotope ratio mass spectrometry for the analysis of polycyclic aromatic hydrocarbons. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:200-208. [PMID: 24338968 DOI: 10.1002/rcm.6769] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/01/2013] [Accepted: 10/18/2013] [Indexed: 06/03/2023]
Abstract
RATIONALE Compound-specific stable isotope analyses of carbon require relatively large amounts of sample for reliable analyses. Commonly applied injections of 1 μL may thus be insufficient for samples with low concentrations of pollutants (e.g. air particulate matter) or when the amount of a sample is limited. METHODS A Large-Volume Injection (LVI) method for carbon stable isotope ratio analysis of Polycyclic Aromatic Hydrocarbons (PAHs) was optimized in this study. Gas chromatography/combustion/isotope ratio mass spectrometry (GCCIRMS) and ion trap mass spectrometry (ITMS) were used for the determination of stable carbon isotope ratios and quantification of compounds, respectively. RESULTS The optimized method resulted in very good reproducibility, even for the most volatile PAH, naphthalene, when a small amount of higher boiling co-solvent was used. No significant fractionation of isotope ratios could be seen and the recoveries of analytes were similar to or better than that of a splitless cold injection. CONCLUSIONS Injection of 100 μL, instead of the commonly used 1 μL, increases the detection limit for PAHs significantly and/or simplifies the sample preparation step. Using our optimized method, stable carbon isotope ratios can be reliably measured in samples with concentrations of PAHs down to 0.05-0.1 ng μL(-1).
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Affiliation(s)
- Anna J Buczyńska
- Joint Research Centre - European Commission, Institute for Reference Materials and Measurements (IRMM), Retiesewg 111, B-2440, Geel, Belgium
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Bouchard D, Hunkeler D. Solvent-based dissolution method to sample gas-phase volatile organic compounds for compound-specific isotope analysis. J Chromatogr A 2014; 1325:16-22. [DOI: 10.1016/j.chroma.2013.11.055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 11/26/2013] [Accepted: 11/27/2013] [Indexed: 10/25/2022]
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Wijker RS, Bolotin J, Nishino SF, Spain JC, Hofstetter TB. Using compound-specific isotope analysis to assess biodegradation of nitroaromatic explosives in the subsurface. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6872-6883. [PMID: 23547531 DOI: 10.1021/es3051845] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Assessing the fate of nitroaromatic explosives in the subsurface is challenging because contaminants are present in different phases (e.g., bound to soil or sediment matrix or as solid-phase residues) and transformation takes place via several potentially competing pathways over time-scales of decades. We developed a procedure for compound-specific analysis of stable C, N, and H isotopes in nitroaromatic compounds (NACs) and characterized biodegradation of 2,4,6-trinitrotoluene (TNT) and two dinitrotoluene isomers (2,4-DNT and 2,6-DNT) in subsurface material of a contaminated site. The type and relative contribution of reductive and oxidative pathways to the degradation of the three contaminants was inferred from the combined evaluation of C, N, and H isotope fractionation. Indicative trends of Δδ(15)N vs Δδ(13)C and Δδ(2)H vs Δδ(13)C were obtained from laboratory model systems for biodegradation pathways initiated via (i) dioxygenation, (ii) reduction, and (iii) CH3-group oxidation. The combined evaluation of NAC isotope fractionation in subsurface materials and in laboratory experiments suggests that in the field, 86-89% of 2,4-DNT transformation was due to dioxygenation while TNT was mostly reduced and 2,6-DNT reacted via a combination of reduction and CH3-group oxidation. Based on historic information on site operation, our data imply biodegradation of 2,4-DNT with half-lives of up to 9-17 years compared to 18-34 years for cometabolic transformation of TNT and 2,6-DNT.
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Affiliation(s)
- Reto S Wijker
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland
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Lee X, Zhang L, Huang D, An N, Yang F, Jiang W, Fang B. Analysis of the stable carbon isotope composition of formic and acetic acids. Anal Biochem 2013; 436:178-86. [DOI: 10.1016/j.ab.2013.01.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 01/17/2013] [Accepted: 01/28/2013] [Indexed: 10/27/2022]
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45
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Kuder T, Philp P. Demonstration of compound-specific isotope analysis of hydrogen isotope ratios in chlorinated ethenes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:1461-1467. [PMID: 23294482 DOI: 10.1021/es303476v] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
High-temperature pyrolysis conversion of organic analytes to H(2) in hydrogen isotope ratio compound-specific isotope analysis (CSIA) is unsuitable for chlorinated compounds such as trichloroethene (TCE) and cis-1,2-dichloroethene (DCE), due to competition from HCl formation. For this reason, the information potential of hydrogen isotope ratios of chlorinated ethenes remains untapped. We present a demonstration of an alternative approach where chlorinated analytes reacted with chromium metal to form H(2) and minor amounts of HCl. The values of δ(2)H were obtained at satisfactory precision (± 10 to 15 per thousand), however the raw data required daily calibration by TCE and/or DCE standards to correct for analytical bias that varies over time. The chromium reactor has been incorporated into a purge and trap-CSIA method that is suitable for CSIA of aqueous environmental samples. A sample data set was obtained for six specimens of commercial product TCE. The resulting values of δ(2)H were between -184 and +682 ‰, which significantly widened the range of manufactured TCE δ(2)H signatures identified by past work. The implications of this finding to the assessment of TCE contamination are discussed.
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Affiliation(s)
- Tomasz Kuder
- School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd Street, SEC 710, Norman, Oklahoma 73019, United States.
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Wuerfel O, Greule M, Keppler F, Jochmann MA, Schmidt TC. Position-specific isotope analysis of the methyl group carbon in methylcobalamin for the investigation of biomethylation processes. Anal Bioanal Chem 2013; 405:2833-41. [PMID: 23325400 DOI: 10.1007/s00216-012-6635-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 11/29/2012] [Accepted: 12/06/2012] [Indexed: 12/18/2022]
Abstract
In the environment, the methylation of metal(loid)s is a widespread phenomenon, which enhances both biomobility as well as mostly the toxicity of the precursory metal(loid)s. Different reaction mechanisms have been proposed for arsenic, but not really proven yet. Here, carbon isotope analysis can foster our understanding of these processes, as the extent of the isotopic fractionation allows to differentiate between different types of reaction, such as concerted (SN2) or stepwise nucleophilic substitution (SN1) as well as to determine the origin of the methyl group. However, for the determination of the kinetic isotope effect the initial isotopic value of the transferred methyl group has to be determined. To that end, we used hydroiodic acid for abstraction of the methyl group from methylcobalamin (CH3Cob) or S-adenosyl methionine (SAM) and subsequent analysis of the formed methyl iodide by gas chromatography (GC) isotope ratio mass spectrometry (IRMS). In addition, three further independent methods have been investigated to determine the position-specific δ (13)C value of CH3Cob involving photolytic cleavage with different additives or thermolytic cleavage of the methyl-cobalt bonding and subsequent measurement of the formed methane by GC-IRMS. The thermolytic cleavage gave comparable results as the abstraction using HI. In contrast, photolysis led to an isotopic fractionation of about 7 to 9 ‰. Furthermore, we extended a recently developed method for the determination of carbon isotope ratios of organometal(loid)s in complex matrices using hydride generation for volatilization and matrix separation before heart-cut GC and IRMS to the analysis of the low boiling partly methylated arsenicals, which are formed in the course of arsenic methylation. Finally, we demonstrated the applicability of this methodology by investigation of carbon fractionation due to the methyl transfer from CH3Cob to arsenic induced by glutathione.
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Affiliation(s)
- Oliver Wuerfel
- Instrumental Analytical Chemistry, University of Duisburg-Essen, Essen, Germany
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Kujawinski DM, Wolbert JB, Zhang L, Jochmann MA, Widory D, Baran N, Schmidt TC. Carbon isotope ratio measurements of glyphosate and AMPA by liquid chromatography coupled to isotope ratio mass spectrometry. Anal Bioanal Chem 2013; 405:2869-78. [DOI: 10.1007/s00216-012-6669-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 12/06/2012] [Accepted: 12/17/2012] [Indexed: 11/28/2022]
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Schreglmann K, Hoeche M, Steinbeiss S, Reinnicke S, Elsner M. Carbon and nitrogen isotope analysis of atrazine and desethylatrazine at sub-microgram per liter concentrations in groundwater. Anal Bioanal Chem 2012; 405:2857-67. [PMID: 23274558 DOI: 10.1007/s00216-012-6616-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 11/26/2012] [Accepted: 11/28/2012] [Indexed: 11/27/2022]
Abstract
Environmental degradation of organic micropollutants is difficult to monitor due to their diffuse and ubiquitous input. Current approaches-concentration measurements over time, or daughter-to-parent compound ratios-may fall short, because they do not consider dilution, compound-specific sorption characteristics or alternative degradation pathways. Compound-specific isotope analysis (CSIA) offers an alternative approach based on evidence from isotope values. Until now, however, the relatively high limits for precise isotope analysis by gas chromatography-isotope ratio mass spectrometry (GC-IRMS) have impeded CSIA of sub-microgram-per-liter scale micropollutant concentrations in field samples. This study presents the first measurements of C and N isotope ratios of the herbicide atrazine and its metabolite desethylatrazine at concentrations of 100 to 1,000 ng/L in natural groundwater samples. Solid-phase extraction and preparative HPLC were tested and validated for preconcentration and cleanup of groundwater samples of up to 10 L without bias by isotope effects. Matrix interferences after solid-phase extraction could be greatly reduced by a preparative HPLC cleanup step prior to GC-IRMS analysis. Sensitivity was increased by a factor of 6 to 8 by changing the injection method from large-volume to cold-on-column injection on the GC-IRMS system. Carbon and nitrogen isotope values of field samples showed no obvious correlation with concentrations or desethylatrazine-to-atrazine ratios. Contrary to expectations, however, δ (13) C values of desethylatrazine were consistently less negative than those of atrazine from the same sites. Potentially, this line of evidence may contain information about further desethylatrazine degradation. In such a case, the common practice of using desethylatrazine-to-atrazine ratios would underestimate natural atrazine degradation.
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Affiliation(s)
- Kathrin Schreglmann
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Groundwater Ecology, Neuherberg, Germany
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Spahr S, Huntscha S, Bolotin J, Maier MP, Elsner M, Hollender J, Hofstetter TB. Compound-specific isotope analysis of benzotriazole and its derivatives. Anal Bioanal Chem 2012; 405:2843-56. [DOI: 10.1007/s00216-012-6526-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/19/2012] [Accepted: 10/24/2012] [Indexed: 10/27/2022]
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Kujawinski DM, Zhang L, Schmidt TC, Jochmann MA. When Other Separation Techniques Fail: Compound-Specific Carbon Isotope Ratio Analysis of Sulfonamide Containing Pharmaceuticals by High-Temperature-Liquid Chromatography-Isotope Ratio Mass Spectrometry. Anal Chem 2012; 84:7656-63. [DOI: 10.1021/ac300116w] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Lijun Zhang
- Instrumental
Analytical Chemistry, University of Duisburg-Essen, 45141 Essen, Germany
| | - Torsten C. Schmidt
- Instrumental
Analytical Chemistry, University of Duisburg-Essen, 45141 Essen, Germany
| | - Maik A. Jochmann
- Instrumental
Analytical Chemistry, University of Duisburg-Essen, 45141 Essen, Germany
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