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Expanding Compound-Specific Isotope Analysis Towards Polar Organic Micropollutants and Chlorine Isotopes

English title Expanding Compound-Specific Isotope Analysis Towards Polar Organic Micropollutants and Chlorine Isotopes
Applicant Hofstetter Thomas
Number 139111
Funding scheme R'EQUIP
Research institution Eawag
Institution of higher education Swiss Federal Institute of Aquatic Science and Technology - EAWAG
Main discipline Other disciplines of Environmental Sciences
Start/End 01.09.2012 - 31.08.2013
Approved amount 240'000.00
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All Disciplines (2)

Discipline
Other disciplines of Environmental Sciences
Other disciplines of Earth Sciences

Keywords (8)

stable isotopes; compound-specific isotope analyis; organic micropollutant; biodegradation; isotope fractionation; isotope ratio mass spectrometry; contaminated site; aquatic system

Lay Summary (English)

Lead
Lay summary

Compound-specific isotope analysis is one of the key techniques for the identification of contaminant sources and assessment of formation and degradation processes of organic micropollutants. While conservative stable isotope ratios measured in individual compounds allow one to infer their precursor materials and (bio)synthesis pathways, stable isotope fractionation is indicative for the reaction mechanisms and extent of contaminant transformation. CSIA therefore contributes to a profound understanding of the reactive processes determining the fate of chemicals and thus to a proper assessment of the temporal and spatial variability of chemical pollution. Applications of CSIA have been particularly successful if isotope ratios were evaluated for two or more isotopic elements simultaneously. However, instrumental restrictions of the most widespread devices for CSIA, gas chromatography coupled to isotope ratio mass spectrometry (GC/IRMS), largely confine the use of CSIA to the elements C, N, H, and O as well as to compounds amenable to gas chromatography. As a consequence, more comprehensive applications that include more polar and ionic micropollutants and halogen isotopes are currently lacking.

With a multifunctional isotope ratio mass spectrometer, a team of environmental chemists and microbiologists will pursue new avenues for the coupling of liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS) and for the analysis of chlorine isotope fractionation in volatile organic contaminants. The LC/IRMS option will be used for the isotopic analysis of polar organic micropollutants and their transformation products as well as for the exploration of isotope fractionation during oxidative transformations of pharmaceuticals and biocides. Chlorine isotope analysis with the dual-inlet IRMS option will enable us to generate reference materials for establishing new procedures of Cl isotope analysis by non-specialized benchtop quadrupol mass spectrometers. The latter will expand our abilities to carry out isotopic analyses beyond the capacity of the requested equipment. To this end, we will investigate the enzymatic mechanisms of isomer-specific hexachlorocyclohexane dechlorination pathways on the basis of C and Cl isotope fractionation analysis. The same isotopic elements will also enable us to use isotope effect as probes for precursor materials and mechanisms responsible for the formation of toxic chlorinated organic disinfection by-products during drinking water treatment.

With the requested instrumentation we will be able to make innovative contributions to emerging applications of CSIA. Moreover, our activities will provide a diverse group of researchers with access to stable-isotope based methods and help to establish new national and international collaborations.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Publications

Publication
Isotope fractionation associated with the simultaneous biodegradation of multiple nitrophenol isomers by Pseudomonas putida B2
Wijker Reto S., Zeyer Josef, Hofstetter Thomas B. (2017), Isotope fractionation associated with the simultaneous biodegradation of multiple nitrophenol isomers by Pseudomonas putida B2, in Environ. Sci.: Processes Impacts, 19(5), 775-784.
Characterization of Substrate, Cosubstrate, and Product Isotope Effects Associated With Enzymatic Oxygenations of Organic Compounds Based on Compound- Specific Isotope Analysis
Pati Sarah G., Kohler Hans-Peter E., Hofstetter Thomas B., Characterization of Substrate, Cosubstrate, and Product Isotope Effects Associated With Enzymatic Oxygenations of Organic Compounds Based on Compound- Specific Isotope Analysis, in Harris Michael, Anderson Vernon (ed.), Elsevier, Amsterdam.

Collaboration

Group / person Country
Types of collaboration
University of Neuchâtel / Daniel Hunkeler Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
Lodz University of Technology / Piotr Paneth Poland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Exchange of personnel
Stockholm University / Örjan Gustafsson, Henry Holmstrand Sweden (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Exchange of personnel
Helmholtz Zentrum München / Martin Elsner Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
University of California Davis / Rebakka Parles United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Isotopes 2013 - Isotope Effects Across Disciplines Talk given at a conference Compound-Specific Isotope Analysis of the Oxidative Degradation of Nitroaromatic Contaminants by Nitrobenzene Dioxygenase 16.06.2013 Sopot, Poland Hofstetter Thomas; Kohler Hans-Peter;


Communication with the public

Communication Title Media Place Year
Print (books, brochures, leaflets) International Innovation International 2013

Awards

Title Year
Best poster award, Isotopes 2013 conference 2013

Associated projects

Number Title Start Funding scheme
104965 Isotope effects in abiotic reduction reactions of chlorinated groundwater contaminants 01.10.2004 Fellowships for advanced researchers
141805 Assessment of micropollutant degradation using multi-element compound-specific isotope analysis 01.07.2013 Sinergia
134720 Using nitrogen isotope fractionation to assess redox reactions of organic contaminants 01.04.2011 Project funding (Div. I-III)
172950 Biodegradation of organic pollutants by mono- and dioxygenation: Insights into rates and mechanisms from isotope effects of oxygen activation and substrate oxygenation 01.03.2018 Project funding (Div. I-III)
153534 Tracking biotransformation of hexachlorocyclohexane isomers by compound specific isotope analysis 01.07.2014 Project funding (Div. I-III)

Abstract

Compound-specific isotope analysis is one of the key techniques for the identification of contam-inant sources and assessment of formation and degradation processes of organic micropollu-tants. While conservative stable isotope ratios measured in individual compounds allow one to infer their precursor materials and (bio)synthesis pathways, stable isotope fractionation is indic-ative for the reaction mechanisms and extent of contaminant (trans)formation. CSIA therefore contributes to a profound understanding of the reactive processes determining the fate of chem-icals and thus to a proper assessment of the temporal and spatial variability of chemical pollu-tion. Applications of CSIA have been particularly successful if isotope ratios were evaluated for two or more isotopic elements simultaneously. However, instrumental restrictions of the most widespread devices for CSIA, gas chromatography coupled to isotope ratio mass spectrometry (GC/IRMS), largely confine the use of CSIA to the elements C, N, H, and O as well as to com-pounds amenable to gas chromatography. As a consequence, more comprehensive applications that include more polar and ionic micropollutants and halogen isotopes are currently lacking.We request funding for a multifunctional isotope ratio mass spectrometer that enables a team of environmental chemists and microbiologists to overcome these instrumental limitations and pursue new avenues for the coupling of liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS) and for the analysis of chlorine isotope fractionation in volatile organic contaminants. Our strategy for the use of the requested instrumentation is based on the devel-opment of new analytical methods and their application in new projects. The LC/IRMS option will be used for the isotopic analysis of polar organic micropollutants and their transformation products as well as for the exploration of isotope fractionation during oxidative transformations of pharmaceuticals and biocides. Chlorine isotope analysis with the dual-inlet IRMS option will enable us to generate reference materials for establishing new procedures of Cl isotope analysis by non-specialized benchtop quadrupol mass spectrometers. The latter will expand our abilities to carry out isotopic analyses beyond the capacity of the requested equipment. To this end, we will investigate the enzymatic mechanisms of isomer-specific hexachlorocyclohexane dechlorin-ation pathways on the basis of C and Cl isotope fractionation analysis. The same isotopic ele-ments will also enable us to use isotope effect as probes for precursor materials and mechanisms responsible for the formation of toxic chlorinated organic disinfection by-products during drink-ing water treatment.With the requested instrumentation we will be able to make innovative contributions to emerging applications of CSIA. Moreover, our activities will provide a diverse group of re-searchers with access to stable-isotope based methods and help to establish new national and international collaborations.
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