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Kelly CL, Manning C, Frey C, Kaiser J, Gluschankoff N, Casciotti KL. Pyisotopomer: A Python package for obtaining intramolecular isotope ratio differences from mass spectrometric analysis of nitrous oxide isotopocules. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9513. [PMID: 36971184 DOI: 10.1002/rcm.9513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 05/16/2023]
Abstract
RATIONALE Obtaining nitrous oxide isotopocule measurements with isotope ratio mass spectrometry (IRMS) involves analyzing the ion current ratios of the nitrous oxide parent ion (N2 O+ ) as well as those of the NO+ fragment ion. The data analysis requires correcting for "scrambling" in the ion source, whereby the NO+ fragment ion obtains the outer N atom from the N2 O molecule. While descriptions exist for this correction, and interlaboratory intercalibration efforts have been made, there has yet to be published a package of code for implementing isotopomer calibrations. METHODS We developed a user-friendly Python package (pyisotopomer) to determine two coefficients (γ and κ) that describe scrambling in the IRMS ion source, and then used this calibration to obtain intramolecular isotope deltas in N2 O samples. RESULTS With two appropriate reference materials, γ and κ can be determined robustly and accurately for a given IRMS system. An additional third reference material is needed to define the zero-point of the delta scale. We show that IRMS scrambling behavior can vary with time, necessitating regular calibrations. Finally, we present an intercalibration between two IRMS laboratories, using pyisotopomer to calculate γ and κ, and to obtain intramolecular N2 O isotope deltas in lake water unknowns. CONCLUSIONS Given these considerations, we discuss how to use pyisotopomer to obtain high-quality N2 O isotopocule data from IRMS systems, including the use of appropriate reference materials and frequency of calibration.
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Affiliation(s)
- Colette L Kelly
- Department of Earth System Science, Stanford University, Stanford, CA, USA
| | - Cara Manning
- Department of Marine Sciences, University of Connecticut, Groton, CT, USA
| | - Claudia Frey
- Department of Environmental Science, University of Basel, Basel, Switzerland
| | - Jan Kaiser
- Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, UK
| | - Noah Gluschankoff
- Department of Earth System Science, Stanford University, Stanford, CA, USA
| | - Karen L Casciotti
- Department of Earth System Science, Stanford University, Stanford, CA, USA
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2
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Mohn J, Biasi C, Bodé S, Boeckx P, Brewer PJ, Eggleston S, Geilmann H, Guillevic M, Kaiser J, Kantnerová K, Moossen H, Müller J, Nakagawa M, Pearce R, von Rein I, Steger D, Toyoda S, Wanek W, Wexler SK, Yoshida N, Yu L. Isotopically characterised N 2 O reference materials for use as community standards. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2022; 36:e9296. [PMID: 35289456 PMCID: PMC9286586 DOI: 10.1002/rcm.9296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 05/28/2023]
Abstract
RATIONALE Information on the isotopic composition of nitrous oxide (N2 O) at natural abundance supports the identification of its source and sink processes. In recent years, a number of mass spectrometric and laser spectroscopic techniques have been developed and are increasingly used by the research community. Advances in this active research area, however, critically depend on the availability of suitable N2 O isotope Reference Materials (RMs). METHODS Within the project Metrology for Stable Isotope Reference Standards (SIRS), seven pure N2 O isotope RMs have been developed and their 15 N/14 N, 18 O/16 O, 17 O/16 O ratios and 15 N site preference (SP) have been analysed by specialised laboratories against isotope reference materials. A particular focus was on the 15 N site-specific isotopic composition, as this measurand is both highly diagnostic for source appointment and challenging to analyse and link to existing scales. RESULTS The established N2 O isotope RMs offer a wide spread in delta (δ) values: δ15 N: 0 to +104‰, δ18 O: +39 to +155‰, and δ15 NSP : -4 to +20‰. Conversion and uncertainty propagation of δ15 N and δ18 O to the Air-N2 and VSMOW scales, respectively, provides robust estimates for δ15 N(N2 O) and δ18 O(N2 O), with overall uncertainties of about 0.05‰ and 0.15‰, respectively. For δ15 NSP , an offset of >1.5‰ compared with earlier calibration approaches was detected, which should be revisited in the future. CONCLUSIONS A set of seven N2 O isotope RMs anchored to the international isotope-ratio scales was developed that will promote the implementation of the recommended two-point calibration approach. Particularly, the availability of δ17 O data for N2 O RMs is expected to improve data quality/correction algorithms with respect to δ15 NSP and δ15 N analysis by mass spectrometry. We anticipate that the N2 O isotope RMs will enhance compatibility between laboratories and accelerate research progress in this emerging field.
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Affiliation(s)
- Joachim Mohn
- Laboratory for Air Pollution/Environmental TechnologyEmpaDübendorfSwitzerland
| | - Christina Biasi
- Department of Environmental and Biological SciencesUniversity of Eastern FinlandKuopioFinland
| | - Samuel Bodé
- Isotope Bioscience Laboratory – ISOFYS, Department of Green Chemistry and Technology, Faculty of Bioscience EngineeringGhent UniversityGhentBelgium
| | - Pascal Boeckx
- Isotope Bioscience Laboratory – ISOFYS, Department of Green Chemistry and Technology, Faculty of Bioscience EngineeringGhent UniversityGhentBelgium
| | | | - Sarah Eggleston
- Laboratory for Air Pollution/Environmental TechnologyEmpaDübendorfSwitzerland
- PAGES International Project OfficeBernSwitzerland
| | - Heike Geilmann
- Beutenberg CampusMax‐Planck‐Institute for BiogeochemistryJenaGermany
| | - Myriam Guillevic
- Laboratory for Air Pollution/Environmental TechnologyEmpaDübendorfSwitzerland
- Air Pollution Control and Chemicals DivisionFederal Office for the EnvironmentBernSwitzerland
| | - Jan Kaiser
- Centre for Ocean and Atmospheric Sciences, School of Environmental SciencesUniversity of East AngliaNorwichUK
| | - Kristýna Kantnerová
- Laboratory for Air Pollution/Environmental TechnologyEmpaDübendorfSwitzerland
- Thermo Fisher ScientificBremenGermany
| | - Heiko Moossen
- Beutenberg CampusMax‐Planck‐Institute for BiogeochemistryJenaGermany
| | - Joanna Müller
- Laboratory for Air Pollution/Environmental TechnologyEmpaDübendorfSwitzerland
- Plant Protection ChemistryAgroscopeWädenswilSwitzerland
| | - Mayuko Nakagawa
- Earth‐Life Science InstituteTokyo Institute of TechnologyTokyoJapan
| | | | - Isabell von Rein
- Beutenberg CampusMax‐Planck‐Institute for BiogeochemistryJenaGermany
| | - David Steger
- Laboratory for Air Pollution/Environmental TechnologyEmpaDübendorfSwitzerland
| | - Sakae Toyoda
- Department of Chemical Science and Engineering, School of Materials and Chemical TechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Wolfgang Wanek
- Terrestrial Ecosystem Research, Centre for Microbiology and Environmental Systems ScienceUniversity of ViennaViennaAustria
| | - Sarah K. Wexler
- Centre for Ocean and Atmospheric Sciences, School of Environmental SciencesUniversity of East AngliaNorwichUK
| | - Naohiro Yoshida
- Earth‐Life Science InstituteTokyo Institute of TechnologyTokyoJapan
- Department of Chemical Science and Engineering, School of Materials and Chemical TechnologyTokyo Institute of TechnologyYokohamaJapan
| | - Longfei Yu
- Laboratory for Air Pollution/Environmental TechnologyEmpaDübendorfSwitzerland
- Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School (SIGS)Tsinghua UniversityShenzhenChina
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3
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Gallarotti N, Barthel M, Verhoeven E, Pereira EIP, Bauters M, Baumgartner S, Drake TW, Boeckx P, Mohn J, Longepierre M, Mugula JK, Makelele IA, Ntaboba LC, Six J. In-depth analysis of N 2O fluxes in tropical forest soils of the Congo Basin combining isotope and functional gene analysis. THE ISME JOURNAL 2021; 15:3357-3374. [PMID: 34035444 PMCID: PMC8528805 DOI: 10.1038/s41396-021-01004-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 04/14/2021] [Accepted: 04/30/2021] [Indexed: 02/04/2023]
Abstract
Primary tropical forests generally exhibit large gaseous nitrogen (N) losses, occurring as nitric oxide (NO), nitrous oxide (N2O) or elemental nitrogen (N2). The release of N2O is of particular concern due to its high global warming potential and destruction of stratospheric ozone. Tropical forest soils are predicted to be among the largest natural sources of N2O; however, despite being the world's second-largest rainforest, measurements of gaseous N-losses from forest soils of the Congo Basin are scarce. In addition, long-term studies investigating N2O fluxes from different forest ecosystem types (lowland and montane forests) are scarce. In this study we show that fluxes measured in the Congo Basin were lower than fluxes measured in the Neotropics, and in the tropical forests of Australia and South East Asia. In addition, we show that despite different climatic conditions, average annual N2O fluxes in the Congo Basin's lowland forests (0.97 ± 0.53 kg N ha-1 year-1) were comparable to those in its montane forest (0.88 ± 0.97 kg N ha-1 year-1). Measurements of soil pore air N2O isotope data at multiple depths suggests that a microbial reduction of N2O to N2 within the soil may account for the observed low surface N2O fluxes and low soil pore N2O concentrations. The potential for microbial reduction is corroborated by a significant abundance and expression of the gene nosZ in soil samples from both study sites. Although isotopic and functional gene analyses indicate an enzymatic potential for complete denitrification, combined gaseous N-losses (N2O, N2) are unlikely to account for the missing N-sink in these forests. Other N-losses such as NO, N2 via Feammox or hydrological particulate organic nitrogen export could play an important role in soils of the Congo Basin and should be the focus of future research.
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Affiliation(s)
- Nora Gallarotti
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Matti Barthel
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Elizabeth Verhoeven
- grid.4391.f0000 0001 2112 1969College of Agricultural Sciences, Oregon State University, Corvallis, OR USA
| | - Engil Isadora Pujol Pereira
- grid.449717.80000 0004 5374 269XSchool of Earth, Environmental, and Marine Sciences, University of Texas Rio Grande Valley, Edinburg, TX USA
| | - Marijn Bauters
- grid.5342.00000 0001 2069 7798Isotope Bioscience Laboratory, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium ,grid.5342.00000 0001 2069 7798Computational and Applied Vegetation Ecology Lab, Department of Environment, Ghent University, Ghent, Belgium
| | - Simon Baumgartner
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland ,grid.7942.80000 0001 2294 713XEarth and Life Institute, Université Catholique de Louvain, Louvain, Belgium
| | - Travis W. Drake
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - Pascal Boeckx
- grid.5342.00000 0001 2069 7798Isotope Bioscience Laboratory, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Joachim Mohn
- grid.7354.50000 0001 2331 3059Laboratory for Air Pollution/Environmental Technology, Swiss Federal Laboratories of Materials Science and Technology, Empa Dubendorf, Switzerland
| | - Manon Longepierre
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
| | - John Kalume Mugula
- grid.442836.f0000 0004 7477 7760Département de Biologie, Université Officielle de Bukavu, Bukavu, Democratic Republic of Congo
| | - Isaac Ahanamungu Makelele
- grid.442836.f0000 0004 7477 7760Département de Biologie, Université Officielle de Bukavu, Bukavu, Democratic Republic of Congo ,grid.5342.00000 0001 2069 7798Department of Green Chemistry and Technology, Ghent University, Ghent, Belgium
| | - Landry Cizungu Ntaboba
- grid.442834.d0000 0004 6011 4325Département d’ Agronomie, Université Catholique de Bukavu, Bukavu, Democratic Republic of Congo
| | - Johan Six
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland
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Kantnerová K, Yu L, Zindel D, Zahniser MS, Nelson DD, Tuzson B, Nakagawa M, Toyoda S, Yoshida N, Emmenegger L, Bernasconi SM, Mohn J. First investigation and absolute calibration of clumped isotopes in N 2 O by mid-infrared laser spectroscopy. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8836. [PMID: 32430945 DOI: 10.1002/rcm.8836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE Unravelling the biogeochemical cycle of the potent greenhouse gas nitrous oxide (N2 O) is an underdetermined problem in environmental sciences due to the multiple source and sink processes involved, which complicate mitigation of its emissions. Measuring the doubly isotopically substituted molecules (isotopocules) of N2 O can add new opportunities to fingerprint and constrain its cycle. METHODS We present a laser spectroscopic technique to selectively and simultaneously measure the eight most abundant isotopocules of N2 O, including three doubly substituted species - so called "clumped isotopes". For the absolute quantification of individual isotopocule abundances, we propose a new calibration scheme that combines thermal equilibration of a working standard gas with a direct mole fraction-based approach. RESULTS The method is validated for a large range of isotopic composition values by comparison with other established methods (laser spectroscopy using conventional isotopic scale and isotope ratio mass spectrometry). Direct intercomparison with recently developed ultrahigh-resolution mass spectrometry shows clearly the advantages of the new laser technique, especially with respect to site specificity of isotopic substitution in the N2 O molecule. CONCLUSIONS Our study represents a new methodological basis for the measurements of both singly substituted and clumped N2 O isotopes. It has a high potential to stimulate future research in the N2 O community by establishing a new class of reservoir-insensitive tracers and molecular-scale insights.
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Affiliation(s)
- Kristýna Kantnerová
- Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, 8600, Switzerland
- ETH Zürich, Department of Earth Sciences, Zürich, 8092, Switzerland
| | - Longfei Yu
- Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, 8600, Switzerland
| | - Daniel Zindel
- ETH Zurich, Laboratory of Physical Chemistry, Zürich, 8093, Switzerland
| | - Mark S Zahniser
- Aerodyne Research Inc., Center for Atmospheric and Environmental Chemistry, Billerica, MA, 01821, USA
| | - David D Nelson
- Aerodyne Research Inc., Center for Atmospheric and Environmental Chemistry, Billerica, MA, 01821, USA
| | - Béla Tuzson
- Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, 8600, Switzerland
| | - Mayuko Nakagawa
- Tokyo Institute of Technology, Earth-Life Science Institute (ELSI), Tokyo, 152-8550, Japan
| | - Sakae Toyoda
- Tokyo Institute of Technology, Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Yokohama, 226-8503, Japan
| | - Naohiro Yoshida
- Tokyo Institute of Technology, Earth-Life Science Institute (ELSI), Tokyo, 152-8550, Japan
- Tokyo Institute of Technology, Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Yokohama, 226-8503, Japan
| | - Lukas Emmenegger
- Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, 8600, Switzerland
| | | | - Joachim Mohn
- Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, 8600, Switzerland
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5
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Adnew GA, Hofmann ME, Paul D, Laskar A, Surma J, Albrecht N, Pack A, Schwieters J, Koren G, Peters W, Röckmann T. Determination of the triple oxygen and carbon isotopic composition of CO 2 from atomic ion fragments formed in the ion source of the 253 Ultra high-resolution isotope ratio mass spectrometer. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:1363-1380. [PMID: 31063233 PMCID: PMC6771542 DOI: 10.1002/rcm.8478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/18/2019] [Accepted: 04/21/2019] [Indexed: 06/09/2023]
Abstract
RATIONALE Determination of δ17 O values directly from CO2 with traditional gas source isotope ratio mass spectrometry is not possible due to isobaric interference of 13 C16 O16 O on 12 C17 O16 O. The methods developed so far use either chemical conversion or isotope equilibration to determine the δ17 O value of CO2 . In addition, δ13 C measurements require correction for the interference from 12 C17 O16 O on 13 C16 O16 O since it is not possible to resolve the two isotopologues. METHODS We present a technique to determine the δ17 O, δ18 O and δ13 C values of CO2 from the fragment ions that are formed upon electron ionization in the ion source of the Thermo Scientific 253 Ultra high-resolution isotope ratio mass spectrometer (hereafter 253 Ultra). The new technique is compared with the CO2 -O2 exchange method and the 17 O-correction algorithm for δ17 O and δ13 C values, respectively. RESULTS The scale contractions for δ13 C and δ18 O values are slightly larger for fragment ion measurements than for molecular ion measurements. The δ17 O and Δ17 O values of CO2 can be measured on the 17 O+ fragment with an internal error that is a factor 1-2 above the counting statistics limit. The ultimate precision depends on the signal intensity and on the total time that the 17 O+ beam is monitored; a precision of 14 ppm (parts per million) (standard error of the mean) was achieved in 20 hours at the University of Göttingen. The Δ17 O measurements with the O-fragment method agree with the CO2 -O2 exchange method over a range of Δ17 O values of -0.3 to +0.7‰. CONCLUSIONS Isotope measurements on atom fragment ions of CO2 can be used as an alternative method to determine the carbon and oxygen isotopic composition of CO2 without chemical processing or corrections for mass interferences.
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Affiliation(s)
- Getachew A. Adnew
- Institute for Marine and Atmospheric research Utrecht (IMAU)Utrecht UniversityThe Netherlands
| | - Magdalena E.G. Hofmann
- Institute for Marine and Atmospheric research Utrecht (IMAU)Utrecht UniversityThe Netherlands
| | - Dipayan Paul
- Institute for Marine and Atmospheric research Utrecht (IMAU)Utrecht UniversityThe Netherlands
- Centre for Isotope ResearchUniversity of GroningenThe Netherlands
| | - Amzad Laskar
- Institute for Marine and Atmospheric research Utrecht (IMAU)Utrecht UniversityThe Netherlands
| | - Jakub Surma
- Geoscience Center GöttingenGeorg‐August‐University GöttingenGermany
| | - Nina Albrecht
- Geoscience Center GöttingenGeorg‐August‐University GöttingenGermany
| | - Andreas Pack
- Geoscience Center GöttingenGeorg‐August‐University GöttingenGermany
| | | | - Gerbrand Koren
- Department of Meteorology and Air QualityWageningen UniversityThe Netherlands
| | - Wouter Peters
- Centre for Isotope ResearchUniversity of GroningenThe Netherlands
- Department of Meteorology and Air QualityWageningen UniversityThe Netherlands
| | - Thomas Röckmann
- Institute for Marine and Atmospheric research Utrecht (IMAU)Utrecht UniversityThe Netherlands
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Castellano‐Hinojosa A, Loick N, Dixon E, Matthews GP, Lewicka‐Szczebak D, Well R, Bol R, Charteris A, Cardenas L. Improved isotopic model based on 15 N tracing and Rayleigh-type isotope fractionation for simulating differential sources of N 2 O emissions in a clay grassland soil. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:449-460. [PMID: 30561863 PMCID: PMC6492082 DOI: 10.1002/rcm.8374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/12/2018] [Accepted: 12/12/2018] [Indexed: 06/09/2023]
Abstract
RATIONALE Isotopic signatures of N2 O can help distinguish between two sources (fertiliser N or endogenous soil N) of N2 O emissions. The contribution of each source to N2 O emissions after N-application is difficult to determine. Here, isotopologue signatures of emitted N2 O are used in an improved isotopic model based on Rayleigh-type equations. METHODS The effects of a partial (33% of surface area, treatment 1c) or total (100% of surface area, treatment 3c) dispersal of N and C on gaseous emissions from denitrification were measured in a laboratory incubation system (DENIS) allowing simultaneous measurements of NO, N2 O, N2 and CO2 over a 12-day incubation period. To determine the source of N2 O emissions those results were combined with both the isotope ratio mass spectrometry analysis of the isotopocules of emitted N2 O and those from the 15 N-tracing technique. RESULTS The spatial dispersal of N and C significantly affected the quantity, but not the timing, of gas fluxes. Cumulative emissions are larger for treatment 3c than treatment 1c. The 15 N-enrichment analysis shows that initially ~70% of the emitted N2 O derived from the applied amendment followed by a constant decrease. The decrease in contribution of the fertiliser N-pool after an initial increase is sooner and larger for treatment 1c. The Rayleigh-type model applied to N2 O isotopocules data (δ15 Nbulk -N2 O values) shows poor agreement with the measurements for the original one-pool model for treatment 1c; the two-pool models gives better results when using a third-order polynomial equation. In contrast, in treatment 3c little difference is observed between the two modelling approaches. CONCLUSIONS The importance of N2 O emissions from different N-pools in soil for the interpretation of N2 O isotopocules data was demonstrated using a Rayleigh-type model. Earlier statements concerning exponential increase in native soil nitrate pool activity highlighted in previous studies should be replaced with a polynomial increase with dependency on both N-pool sizes.
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Affiliation(s)
- Antonio Castellano‐Hinojosa
- Department of Microbiology, Faculty of PharmacyUniversity of Granada. Campus Cartuja18071GranadaSpain
- Department of Soil Microbiology and Symbiotic SystemsEstación Experimental del Zaidín18080GranadaSpain
| | - Nadine Loick
- Rothamsted Research, North WykeOkehamptonEX20 2SBUK
| | | | - G. Peter Matthews
- School of Geography, Earth and Environmental SciencesUniversity of PlymouthDavy Building, Drake CircusPlymouthPL4 8AAUK
| | | | - Reinhard Well
- Thünen Institute of Climate‐Smart AgricultureBundesallee 6538116BraunschweigGermany
| | - Roland Bol
- Agrosphere (IBG‐3)Institute of Bio‐ and GeosciencesForschungszentrum Jülich52428JülichGermany
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7
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Hyodo A, Malghani S, Zhou Y, Mushinski RM, Toyoda S, Yoshida N, Boutton TW, West JB. Biochar amendment suppresses N 2 O emissions but has no impact on 15 N site preference in an anaerobic soil. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:165-175. [PMID: 30304571 DOI: 10.1002/rcm.8305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE Biochar amendments often decrease N2 O gas production from soil, but the mechanisms and magnitudes are still not well characterized since N2 O can be produced via several different microbial pathways. We evaluated the influence of biochar amendment on N2 O emissions and N2 O isotopic composition, including 15 N site preference (SP) under anaerobic conditions. METHODS An agricultural soil was incubated with differing levels of biochar. Incubations were conducted under anaerobic conditions for 10 days with and without acetylene, which inhibits N2 O reduction to N2 . The N2 O concentrations were measured every 2 days, the SPs were determined after 5 days of incubation, and the inorganic nitrogen concentrations were measured after the incubation. RESULTS The SP values with acetylene were consistent with N2 O production by bacterial denitrification and those without acetylene were consistent with bacterial denitrification that included N2 O reduction to N2 . There was no effect of biochar on N2 O production in the presence of acetylene between day 3 and day 10. However, in the absence of acetylene, soils incubated with 4% biochar produced less N2 O than soils with no biochar addition. Different amounts of biochar amendment did not change the SP values. CONCLUSIONS Our study used N2 O emission rates and SP values to understand biochar amendment mechanisms and demonstrated that biochar amendment reduces N2 O emissions by stimulating the last step of denitrification. It also suggested a possible shift in N2 O-reducing microbial taxa in 4% biochar samples.
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Affiliation(s)
- Ayumi Hyodo
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, 77843, USA
| | - Saadatullah Malghani
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, 77843, USA
- School of Civil and Environmental Engineering, Yonsei University, Yonsei-ro 50 Saedaemun-gu, Seoul, 03722, South Korea
| | - Yong Zhou
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, 77843, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06511, USA
| | - Ryan M Mushinski
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, 77843, USA
- School of Public and Environmental Affairs, Indiana University, Bloomington, IN, 47405, USA
| | - Sakae Toyoda
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Naohiro Yoshida
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Thomas W Boutton
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, 77843, USA
| | - Jason B West
- Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, 77843, USA
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8
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Buchen C, Lewicka-Szczebak D, Flessa H, Well R. Estimating N 2 O processes during grassland renewal and grassland conversion to maize cropping using N 2 O isotopocules. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:1053-1067. [PMID: 29603803 DOI: 10.1002/rcm.8132] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/21/2018] [Accepted: 03/21/2018] [Indexed: 05/27/2023]
Abstract
RATIONALE Enhanced nitrous oxide (N2 O) emissions can occur following grassland break-up for renewal or conversion to maize cropping, but knowledge about N2 O production pathways and N2 O reduction to N2 is very limited. A promising tool to address this is the combination of mass spectrometric analysis of N2 O isotopocules and an enhanced approach for data interpretation. METHODS The isotopocule mapping approach was applied to field data using a δ15 NspN2O and δ18 ON2O map to simultaneously determine N2 O production pathways contribution and N2 O reduction for the first time. Based on the isotopic composition of N2 O produced and literature values for specific N2 O pathways, it was possible to distinguish: (i) heterotrophic bacterial denitrification and/or nitrifier denitrification and (ii) nitrification and/or fungal denitrification and the contribution of N2 O reduction. RESULTS The isotopic composition of soil-emitted N2 O largely resembled the known end-member values for bacterial denitrification. The isotopocule mapping approach indicated different effects of N2 O reduction on the isotopic composition of soil-emitted N2 O for the two soils under study. Differing N2 O production pathways in different seasons were not observed, but management events and soil conditions had a significant impact on pathway contribution and N2 O reduction. N2 O reduction data were compared with a parallel 15 N-labelling experiment. CONCLUSIONS The field application of the isotopocule mapping approach opens up new prospects for studying N2 O production and consumption of N2 O in soil simultaneously based on mass spectrometric analysis of natural abundance N2 O. However, further studies are needed in order to properly validate the isotopocule mapping approach.
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Affiliation(s)
- Caroline Buchen
- Thünen-Institute of Climate-Smart Agriculture, Bundesallee 50, 38116, Braunschweig, Germany
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374, Muencheberg, Germany
| | | | - Heinz Flessa
- Thünen-Institute of Climate-Smart Agriculture, Bundesallee 50, 38116, Braunschweig, Germany
| | - Reinhard Well
- Thünen-Institute of Climate-Smart Agriculture, Bundesallee 50, 38116, Braunschweig, Germany
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9
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Ibraim E, Harris E, Eyer S, Tuzson B, Emmenegger L, Six J, Mohn J. Development of a field-deployable method for simultaneous, real-time measurements of the four most abundant N 2O isotopocules. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2018; 54:1-15. [PMID: 28681639 DOI: 10.1080/10256016.2017.1345902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 04/25/2017] [Indexed: 05/21/2023]
Abstract
Understanding and quantifying the biogeochemical cycle of N2O is essential to develop effective N2O emission mitigation strategies. This study presents a novel, fully automated measurement technique that allows simultaneous, high-precision quantification of the four main N2O isotopocules (14N14N16O, 14N15N16O, 15N14N16O and 14N14N18O) in ambient air. The instrumentation consists of a trace gas extractor (TREX) coupled to a quantum cascade laser absorption spectrometer, designed for autonomous operation at remote measurement sites. The main advantages this system has over its predecessors are a compact spectrometer design with improved temperature control and a more compact and powerful TREX device. The adopted TREX device enhances the flexibility of the preconcentration technique for higher adsorption volumes to target rare isotope species and lower adsorption temperatures for highly volatile substances. All system components have been integrated into a standardized instrument rack to improve portability and accessibility for maintenance. With an average sampling frequency of approximately 1 h-1, this instrumentation achieves a repeatability of 0.09, 0.13, 0.17 and 0.12 ‰ for δ15Nα, δ15Nβ, δ18O and site preference of N2O, respectively, for pressurized ambient air. The repeatability for N2O mole fraction measurements is better than 1 ppb (parts per billion, 10-9 moles per mole of dry air).
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Affiliation(s)
- Erkan Ibraim
- a Laboratory for Air Pollution/Environmental Technology , Empa - Swiss Federal Laboratories for Materials Science and Technology , Dübendorf , Switzerland
- b Department of Environmental Systems Science , ETH-Zürich, Swiss Federal Institute of Technology , Zürich , Switzerland
| | - Eliza Harris
- a Laboratory for Air Pollution/Environmental Technology , Empa - Swiss Federal Laboratories for Materials Science and Technology , Dübendorf , Switzerland
| | - Simon Eyer
- a Laboratory for Air Pollution/Environmental Technology , Empa - Swiss Federal Laboratories for Materials Science and Technology , Dübendorf , Switzerland
| | - Béla Tuzson
- a Laboratory for Air Pollution/Environmental Technology , Empa - Swiss Federal Laboratories for Materials Science and Technology , Dübendorf , Switzerland
| | - Lukas Emmenegger
- a Laboratory for Air Pollution/Environmental Technology , Empa - Swiss Federal Laboratories for Materials Science and Technology , Dübendorf , Switzerland
| | - Johan Six
- b Department of Environmental Systems Science , ETH-Zürich, Swiss Federal Institute of Technology , Zürich , Switzerland
| | - Joachim Mohn
- a Laboratory for Air Pollution/Environmental Technology , Empa - Swiss Federal Laboratories for Materials Science and Technology , Dübendorf , Switzerland
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10
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Duan H, Ye L, Erler D, Ni BJ, Yuan Z. Quantifying nitrous oxide production pathways in wastewater treatment systems using isotope technology - A critical review. WATER RESEARCH 2017; 122:96-113. [PMID: 28595125 DOI: 10.1016/j.watres.2017.05.054] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/01/2017] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
Nitrous oxide (N2O) is an important greenhouse gas and an ozone-depleting substance which can be emitted from wastewater treatment systems (WWTS) causing significant environmental impacts. Understanding the N2O production pathways and their contribution to total emissions is the key to effective mitigation. Isotope technology is a promising method that has been applied to WWTS for quantifying the N2O production pathways. Within the scope of WWTS, this article reviews the current status of different isotope approaches, including both natural abundance and labelled isotope approaches, to N2O production pathways quantification. It identifies the limitations and potential problems with these approaches, as well as improvement opportunities. We conclude that, while the capabilities of isotope technology have been largely recognized, the quantification of N2O production pathways with isotope technology in WWTS require further improvement, particularly in relation to its accuracy and reliability.
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Affiliation(s)
- Haoran Duan
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Dirk Erler
- Centre for Coastal Biogeochemistry, School of Environmental Science and Engineering, Southern Cross University, Lismore, NSW 2480 Australia
| | - Bing-Jie Ni
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
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11
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Toyoda S, Yoshida N, Koba K. Isotopocule analysis of biologically produced nitrous oxide in various environments. MASS SPECTROMETRY REVIEWS 2017; 36:135-160. [PMID: 25869149 DOI: 10.1002/mas.21459] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 01/13/2015] [Accepted: 01/13/2015] [Indexed: 06/04/2023]
Abstract
Natural abundance ratios of isotopocules, molecules that have the same chemical constitution and configuration, but that only differ in isotope substitution, retain a record of a compound's origin and reactions. A method to measure isotopocule ratios of nitrous oxide (N2 O) has been established by using mass analysis of molecular ions and fragment ions. The method has been applied widely to environmental samples from the atmosphere, ocean, fresh water, soils, and laboratory-simulation experiments. Results show that isotopocule ratios, particularly the 15 N-site preference (difference between isotopocule ratios 14 N15 N16 O/14 N14 N16 O and 15 N14 N16 O/14 N14 N16 O), have a wide range that depends on their production and consumption processes. Observational and laboratory studies of N2 O related to biological processes are reviewed and discussed to elucidate complex material cycles of this trace gas, which causes global warming and stratospheric ozone depletion. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:135-160, 2017.
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Affiliation(s)
- Sakae Toyoda
- Department of Environmental Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
| | - Naohiro Yoshida
- Department of Environmental Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
- Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Keisuke Koba
- Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-City, Tokyo 183-8509, Japan
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12
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Mohn J, Gutjahr W, Toyoda S, Harris E, Ibraim E, Geilmann H, Schleppi P, Kuhn T, Lehmann MF, Decock C, Werner RA, Yoshida N, Brand WA. Reassessment of the NH 4 NO 3 thermal decomposition technique for calibration of the N 2 O isotopic composition. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:2487-2496. [PMID: 27605461 DOI: 10.1002/rcm.7736] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/22/2016] [Accepted: 09/05/2016] [Indexed: 05/21/2023]
Abstract
RATIONALE In the last few years, the study of N2 O site-specific nitrogen isotope composition has been established as a powerful technique to disentangle N2 O emission pathways. This trend has been accelerated by significant analytical progress in the field of isotope ratio mass spectrometry (IRMS) and more recently quantum cascade laser absorption spectroscopy (QCLAS). METHODS The ammonium nitrate (NH4 NO3 ) decomposition technique provides a strategy to scale the 15 N site-specific (SP ≡ δ15 Nα - δ15 Nβ ) and bulk (δ15 Nbulk = (δ15 Nα + δ15 Nβ )/2) isotopic composition of N2 O against the international standard for the 15 N/14 N isotope ratio (AIR-N2 ). Within the current project 15 N fractionation effects during thermal decomposition of NH4 NO3 on the N2 O site preference were studied using static and dynamic decomposition techniques. RESULTS The validity of the NH4 NO3 decomposition technique to link NH4+ and NO3- moiety-specific δ15 N analysis by IRMS to the site-specific nitrogen isotopic composition of N2 O was confirmed. However, the accuracy of this approach for the calibration of δ15 Nα and δ15 Nβ values was found to be limited by non-quantitative NH4 NO3 decomposition in combination with substantially different isotope enrichment factors for the conversion of the NO3- or NH4+ nitrogen atom into the α or β position of the N2 O molecule. CONCLUSIONS The study reveals that the completeness and reproducibility of the NH4 NO3 decomposition reaction currently confine the anchoring of N2 O site-specific isotopic composition to the international isotope ratio scale AIR-N2 . The authors suggest establishing a set of N2 O isotope reference materials with appropriate site-specific isotopic composition, as community standards, to improve inter-laboratory compatibility. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Joachim Mohn
- Laboratory for Air Pollution & Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstr. 129,, CH-8600, Dübendorf, Switzerland
| | - Wilhelm Gutjahr
- Laboratory for Air Pollution & Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstr. 129,, CH-8600, Dübendorf, Switzerland
| | - Sakae Toyoda
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8502, Japan
| | - Eliza Harris
- Laboratory for Air Pollution & Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstr. 129,, CH-8600, Dübendorf, Switzerland
| | - Erkan Ibraim
- Laboratory for Air Pollution & Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstr. 129,, CH-8600, Dübendorf, Switzerland
| | - Heike Geilmann
- Stable Isotope Laboratory (IsoLab), Max-Planck-Institute for Biogeochemistry (MPI-BGC), Hans-Knöll-Str. 10,, D-07745, Jena, Germany
| | - Patrick Schleppi
- Forest Soils and Biogeochemistry, WSL, Zürcherstrasse 111,, CH-8903, Birmensdorf, Switzerland
| | - Thomas Kuhn
- Biogeochemistry, University of Basel, Bernoullistrasse 30,, CH-4056, Basel, Switzerland
| | - Moritz F Lehmann
- Biogeochemistry, University of Basel, Bernoullistrasse 30,, CH-4056, Basel, Switzerland
| | - Charlotte Decock
- Sustainable Agroecosystems, ETH Zürich, Tannenstrasse 1,, CH-8092, Zürich, Switzerland
| | - Roland A Werner
- Institute of Agricultural Sciences, ETH Zürich, Universitätstrasse 2, CH-8092, Zürich, Switzerland
| | - Naohiro Yoshida
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8502, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Willi A Brand
- Stable Isotope Laboratory (IsoLab), Max-Planck-Institute for Biogeochemistry (MPI-BGC), Hans-Knöll-Str. 10,, D-07745, Jena, Germany
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13
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Magyar PM, Orphan VJ, Eiler JM. Measurement of rare isotopologues of nitrous oxide by high-resolution multi-collector mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1923-1940. [PMID: 27501428 DOI: 10.1002/rcm.7671] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/16/2016] [Accepted: 06/18/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE Bulk and position-specific stable isotope characterization of nitrous oxide represents one of the most powerful tools for identifying its environmental sources and sinks. Constraining (14) N(15) N(18) O and (15) N(14) N(18) O will add two new dimensions to our ability to uniquely fingerprint N2 O sources. METHODS We describe a technique to measure six singly and doubly substituted isotopic variants of N2 O, constraining the values of δ(15) N, δ(18) O, ∆(17) O, (15) N site preference, and the clumped isotopomers (14) N(15) N(18) O and (15) N(14) N(18) O. The technique uses a Thermo MAT 253 Ultra, a high-resolution multi-collector gas source isotope ratio mass spectrometer. It requires 8-10 hours per sample and ~10 micromoles or more of pure N2 O. RESULTS We demonstrate the precision and accuracy of these measurements by analyzing N2 O brought to equilibrium in its position-specific and clumped isotopic composition by heating in the presence of a catalyst. Finally, an illustrative analysis of biogenic N2 O from a denitrifying bacterium suggests that its clumped isotopic composition is controlled by kinetic isotope effects in N2 O production. CONCLUSIONS We developed a method for measuring six isotopic variants of N2 O and tested it with analyses of biogenic N2 O. The added isotopic constraints provided by these measurements will enhance our ability to apportion N2 O sources.
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Affiliation(s)
- Paul M Magyar
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - John M Eiler
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
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14
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Abstract
High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules.
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15
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Lewicka-Szczebak D, Well R, Bol R, Gregory AS, Matthews GP, Misselbrook T, Whalley WR, Cardenas LM. Isotope fractionation factors controlling isotopocule signatures of soil-emitted N₂O produced by denitrification processes of various rates. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:269-282. [PMID: 26411625 DOI: 10.1002/rcm.7102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 11/14/2014] [Accepted: 11/17/2014] [Indexed: 06/05/2023]
Abstract
RATIONALE This study aimed (i) to determine the isotopic fractionation factors associated with N2O production and reduction during soil denitrification and (ii) to help specify the factors controlling the magnitude of the isotope effects. For the first time the isotope effects of denitrification were determined in an experiment under oxic atmosphere and using a novel approach where N2O production and reduction occurred simultaneously. METHODS Soil incubations were performed under a He/O2 atmosphere and the denitrification product ratio [N2O/(N2 + N2O)] was determined by direct measurement of N2 and N2O fluxes. N2O isotopocules were analyzed by mass spectrometry to determine δ(18)O, δ(15)N and (15)N site preference within the linear N2O molecule (SP). An isotopic model was applied for the simultaneous determination of net isotope effects (η) of both N2O production and reduction, taking into account emissions from two distinct soil pools. RESULTS A clear relationship was observed between (15)N and (18)O isotope effects during N2O production and denitrification rates. For N2O reduction, diverse isotope effects were observed for the two distinct soil pools characterized by different product ratios. For moderate product ratios (from 0.1 to 1.0) the range of isotope effects given by previous studies was confirmed and refined, whereas for very low product ratios (below 0.1) the net isotope effects were much smaller. CONCLUSIONS The fractionation factors associated with denitrification, determined under oxic incubation, are similar to the factors previously determined under anoxic conditions, hence potentially applicable for field studies. However, it was shown that the η(18)O/η(15)N ratios, previously accepted as typical for N2O reduction processes (i.e., higher than 2), are not valid for all conditions.
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Affiliation(s)
- Dominika Lewicka-Szczebak
- Thünen Institute of Climate-Smart Agriculture, Federal Research Institute for Rural Areas, Forestry and Fisheries, Bundesallee 50, D-38116, Braunschweig, Germany
- Institute of Geological Sciences, University of Wrocław, Cybulskiego 30, PL-50-205, Wroclaw, Poland
| | - Reinhard Well
- Thünen Institute of Climate-Smart Agriculture, Federal Research Institute for Rural Areas, Forestry and Fisheries, Bundesallee 50, D-38116, Braunschweig, Germany
| | - Roland Bol
- Forschungszentrum Jülich IBG-3, Wilhelm-Johnen-Straße, 52428, Jülich, Germany
| | | | - G Peter Matthews
- Faculty of Science & Environment, University of Plymouth, Plymouth, PL4 8AA, UK
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16
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Li J, Zhang L, Yu B. Site-selective nitrogen isotopic ratio measurement of nitrous oxide using a TE-cooled CW-RT-QCL based spectrometer. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 133:489-494. [PMID: 24973790 DOI: 10.1016/j.saa.2014.06.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/16/2014] [Accepted: 06/05/2014] [Indexed: 06/03/2023]
Abstract
The feasibility of laser spectroscopic isotopic composition measurements of atmospheric N2O was demonstrated, although making them useful will require further improvements. The system relies on a thermoelectrically (TE) cooled continuous-wave (CW) room temperature (RT) quantum cascade laser source emitting wavelength of around 4.6μm, where strong fundamental absorption bands occur for the considered specie and its isotopomers. The analysis technique is based on wavelength modulation spectroscopy with second-harmonic detection and the combination of long-path absorption cell. Primary laboratory tests have been performed to estimate the achievable detection limits and the signal reproducibility levels in view of possible measurements of (15)N/(14)N and (18)O/(16)O isotope ratios. The experiment results showed that the site-selective (15)N/(14)N ratio can be measured with a precision of 3‰ with 90s averaging time using natural-abundance N2O sample of 12.7ppm.
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Affiliation(s)
- Jingsong Li
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, China.
| | - Lizhu Zhang
- School of Science, Tianjin University of Technology and Education, Tianjin, China
| | - Benli Yu
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, China
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17
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O’Sullivan D, McLaughlin RP, Clemitshaw KC, Sodeau JR. Cold-Surface Photochemistry of Selected Organic Nitrates. J Phys Chem A 2014; 118:9890-900. [DOI: 10.1021/jp5065424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Ryan P. McLaughlin
- Department
of Chemistry, Seattle University, 901 12th Avenue, Seattle, Washington 98122, United States
| | - Kevin C. Clemitshaw
- Department
of Earth Sciences, Royal Holloway, University of London Egham, Surrey TW20 0EX, U.K
| | - John R. Sodeau
- Department
of Chemistry, Centre for Research into Atmospheric Chemistry, University College, Cork, Ireland
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18
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Mohn J, Wolf B, Toyoda S, Lin CT, Liang MC, Brüggemann N, Wissel H, Steiker AE, Dyckmans J, Szwec L, Ostrom NE, Casciotti KL, Forbes M, Giesemann A, Well R, Doucett RR, Yarnes CT, Ridley AR, Kaiser J, Yoshida N. Interlaboratory assessment of nitrous oxide isotopomer analysis by isotope ratio mass spectrometry and laser spectroscopy: current status and perspectives. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:1995-2007. [PMID: 25132300 DOI: 10.1002/rcm.6982] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/09/2014] [Accepted: 07/11/2014] [Indexed: 06/03/2023]
Abstract
RATIONALE In recent years, research and applications of the N2O site-specific nitrogen isotope composition have advanced, reflecting awareness of the contribution of N2O to the anthropogenic greenhouse effect, and leading to significant progress in instrument development. Further dissemination of N2O isotopomer analysis, however, is hampered by a lack of internationally agreed gaseous N2O reference materials and an uncertain compatibility of different laboratories and analytical techniques. METHODS In a first comparison approach, eleven laboratories were each provided with N2O at tropospheric mole fractions (target gas T) and two reference gases (REF1 and REF2). The laboratories analysed all gases, applying their specific analytical routines. Compatibility of laboratories was assessed based on N2O isotopocule data for T, REF1 and REF2. Results for T were then standardised using REF1 and REF2 to evaluate the potential of N2O reference materials for improving compatibility between laboratories. RESULTS Compatibility between laboratories depended on the analytical technique: isotope ratio mass spectrometry (IRMS) results showed better compatibility for δ(15)N values, while the performance of laser spectroscopy was superior with respect to N2O site preference. This comparison, however, is restricted by the small number of participating laboratories applying laser spectroscopy. Offset and two-point calibration correction of the N2O isotopomer data significantly improved the consistency of position-dependent nitrogen isotope data while the effect on δ(15)N values was only minor. CONCLUSIONS The study reveals that for future research on N2O isotopocules, standardisation against N2O reference material is essential to improve interlaboratory compatibility. For atmospheric monitoring activities, we suggest N2O in whole air as a unifying scale anchor.
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Affiliation(s)
- Joachim Mohn
- Laboratory for Air Pollution & Environmental Technology, Empa, Überlandstr. 129, CH-8600, Dübendorf, Switzerland
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19
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Thuss SJ, Venkiteswaran JJ, Schiff SL. Proper interpretation of dissolved nitrous oxide isotopes, production pathways, and emissions requires a modelling approach. PLoS One 2014; 9:e90641. [PMID: 24608915 PMCID: PMC3946536 DOI: 10.1371/journal.pone.0090641] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 02/03/2014] [Indexed: 11/18/2022] Open
Abstract
Stable isotopes ([Formula: see text]15N and [Formula: see text]18O) of the greenhouse gas N2O provide information about the sources and processes leading to N2O production and emission from aquatic ecosystems to the atmosphere. In turn, this describes the fate of nitrogen in the aquatic environment since N2O is an obligate intermediate of denitrification and can be a by-product of nitrification. However, due to exchange with the atmosphere, the [Formula: see text] values at typical concentrations in aquatic ecosystems differ significantly from both the source of N2O and the N2O emitted to the atmosphere. A dynamic model, SIDNO, was developed to explore the relationship between the isotopic ratios of N2O, N2O source, and the emitted N2O. If the N2O production rate or isotopic ratios vary, then the N2O concentration and isotopic ratios may vary or be constant, not necessarily concomitantly, depending on the synchronicity of production rate and source isotopic ratios. Thus prima facie interpretation of patterns in dissolved N2O concentrations and isotopic ratios is difficult. The dynamic model may be used to correctly interpret diel field data and allows for the estimation of the gas exchange coefficient, N2O production rate, and the production-weighted [Formula: see text] values of the N2O source in aquatic ecosystems. Combining field data with these modelling efforts allows this critical piece of nitrogen cycling and N2O flux to the atmosphere to be assessed.
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Affiliation(s)
- Simon J. Thuss
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Jason J. Venkiteswaran
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada
- * E-mail:
| | - Sherry L. Schiff
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario, Canada
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21
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Harris E, Nelson DD, Olszewski W, Zahniser M, Potter KE, McManus BJ, Whitehill A, Prinn RG, Ono S. Development of a Spectroscopic Technique for Continuous Online Monitoring of Oxygen and Site-Specific Nitrogen Isotopic Composition of Atmospheric Nitrous Oxide. Anal Chem 2014; 86:1726-34. [DOI: 10.1021/ac403606u] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eliza Harris
- Department
of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139 United States
- Laboratory
for Air Pollution and Environmental Technology, Swiss Federal Institute for Materials Science and Technology (EMPA), Überlandstrasse 129, 8600 Dübendorf, Switzerland
| | - David D. Nelson
- Atmospheric
and Environmental Chemistry, Aerodyne Research Inc., 45 Manning Road, Billerica, Massachusetts, 01821 United States
| | - William Olszewski
- Department
of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139 United States
| | - Mark Zahniser
- Atmospheric
and Environmental Chemistry, Aerodyne Research Inc., 45 Manning Road, Billerica, Massachusetts, 01821 United States
| | - Katherine E. Potter
- Department
of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139 United States
| | - Barry J. McManus
- Atmospheric
and Environmental Chemistry, Aerodyne Research Inc., 45 Manning Road, Billerica, Massachusetts, 01821 United States
| | - Andrew Whitehill
- Department
of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139 United States
| | - Ronald G. Prinn
- Department
of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139 United States
| | - Shuhei Ono
- Department
of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139 United States
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22
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Potter KE, Ono S, Prinn RG. Fully automated, high-precision instrumentation for the isotopic analysis of tropospheric N2O using continuous flow isotope ratio mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:1723-1738. [PMID: 23821566 DOI: 10.1002/rcm.6623] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE Measurements of the isotopic composition of nitrous oxide in the troposphere have the potential to bring new information about the uncertain N2O budget, which mole fraction data alone have not been able to resolve. Characterizing the expected subtle variations in tropospheric N2O isotopic composition demands high-precision and high-frequency measurements. To enable useful observations of N2O isotopic composition in tropospheric air to reduce N2O source and sink uncertainty, it was necessary to develop a high-precision measurement system with fully automated capabilities for autonomous deployment at remote research stations. METHODS A fully automated pre-concentration system for high-precision measurements of N2O isotopic composition (δ(15)N(β) , δ(15)N(α), δ(18)O) in tropospheric air has been developed which combines a custom liquid-cryogen-free cryo-trapping system and gas chromatograph interfaced to a continuous flow isotope ratio mass spectrometry (IRMS) system. A quadrupole mass spectrometer was coupled in parallel to the IRMS system during development to evaluate peak interference. Multi-port inlet and fully-automated capabilities allow streamlined analyses between in situ air inlet, air standards, flask air sample, or other gas source in exactly replicated analysis sequences. RESULTS The system has the highest precision to date for (15)N site-specific composition results (δ(15) N(α) ±0.11‰, δ(15)N(β) ±0.14‰ (1σ)), attributed mostly to uniformity of analytical cycles and particular attention to fluorocarbon interference noted for (15)N site-specific measurements by IRMS. Air measurements demonstrated the fully automated capacity and performance. CONCLUSIONS The system makes substantial headway in measurement precision, possibly defining the limits of IRMS measurement capabilities in low concentration N2O air samples, with fully automated capabilities to enable high-frequency in situ measurements.
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Affiliation(s)
- Katherine E Potter
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
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Wunderlin P, Lehmann MF, Siegrist H, Tuzson B, Joss A, Emmenegger L, Mohn J. Isotope signatures of N₂O in a mixed microbial population system: constraints on N₂O producing pathways in wastewater treatment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:1339-48. [PMID: 23249174 DOI: 10.1021/es303174x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We present measurements of site preference (SP) and bulk (15)N/(14)N ratios (δ(15)N(bulk)(N2O)) of nitrous oxide (N(2)O) by quantum cascade laser absorption spectroscopy (QCLAS) as a powerful tool to investigate N(2)O production pathways in biological wastewater treatment. QCLAS enables high-precision N(2)O isotopomer analysis in real time. This allowed us to trace short-term fluctuations in SP and δ(15)N(bulk)(N2O) and, hence, microbial transformation pathways during individual batch experiments with activated sludge from a pilot-scale facility treating municipal wastewater. On the basis of previous work with microbial pure cultures, we demonstrate that N(2)O emitted during ammonia (NH(4)(+)) oxidation with a SP of -5.8 to 5.6 ‰ derives mostly from nitrite (NO(2)(-)) reduction (e.g., nitrifier denitrification), with a minor contribution from hydroxylamine (NH(2)OH) oxidation at the beginning of the experiments. SP of N(2)O produced under anoxic conditions was always positive (1.2 to 26.1 ‰), and SP values at the high end of this spectrum (24.9 to 26.1 ‰) are indicative of N(2)O reductase activity. The measured δ(15)N(bulk)(N2O) at the initiation of the NH(4)(+) oxidation experiments ranged between -42.3 and -57.6 ‰ (corresponding to a nitrogen isotope effect Δδ(15)N = δ(15)N(substrate) - δ(15)N(bulk)(N2O) of 43.5 to 58.8 ‰), which is considerably higher than under denitrifying conditions (δ(15)N(bulk)(N2O) 2.4 to -17 ‰; Δδ(15)N = 0.1 to 19.5 ‰). During the course of all NH(4)(+) oxidation and nitrate (NO(3)(-)) reduction experiments, δ(15)N(bulk)(N2O) increased significantly, indicating net (15)N enrichment in the dissolved inorganic nitrogen substrates (NH(4)(+), NO(3)(-)) and transfer into the N(2)O pool. The decrease in δ(15)N(bulk)(N2O) during NO(2)(-) and NH(2)OH oxidation experiments is best explained by inverse fractionation during the oxidation of NO(2)(-) to NO(3)(-).
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Affiliation(s)
- Pascal Wunderlin
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, P.O. Box 611, 8600 Duebendorf, Switzerland.
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Köster JR, Well R, Tuzson B, Bol R, Dittert K, Giesemann A, Emmenegger L, Manninen A, Cárdenas L, Mohn J. Novel laser spectroscopic technique for continuous analysis of N2O isotopomers--application and intercomparison with isotope ratio mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:216-222. [PMID: 23239336 DOI: 10.1002/rcm.6434] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 10/03/2012] [Accepted: 10/08/2012] [Indexed: 06/01/2023]
Abstract
RATIONALE Nitrous oxide (N(2)O), a highly climate-relevant trace gas, is mainly derived from microbial denitrification and nitrification processes in soils. Apportioning N(2)O to these source processes is a challenging task, but better understanding of the processes is required to improve mitigation strategies. The N(2)O site-specific (15)N signatures from denitrification and nitrification have been shown to be clearly different, making this signature a potential tool for N(2)O source identification. We have applied for the first time quantum cascade laser absorption spectroscopy (QCLAS) for the continuous analysis of the intramolecular (15)N distribution of soil-derived N(2)O and compared this with state-of-the-art isotope ratio mass spectrometry (IRMS). METHODS Soil was amended with nitrate and sucrose and incubated in a laboratory setup. The N(2)O release was quantified by FTIR spectroscopy, while the N(2)O intramolecular (15)N distribution was continuously analyzed by online QCLAS at 1 Hz resolution. The QCLAS results on time-integrating flask samples were compared with those from the IRMS analysis. RESULTS The analytical precision (2σ) of QCLAS was around 0.3‰ for the δ(15)N(bulk) and the (15)N site preference (SP) for 1-min average values. Comparing the two techniques on flask samples, excellent agreement (R(2)= 0.99; offset of 1.2‰) was observed for the δ(15)N(bulk) values while for the SP values the correlation was less good (R(2 )= 0.76; offset of 0.9‰), presumably due to the lower precision of the IRMS SP measurements. CONCLUSIONS These findings validate QCLAS as a viable alternative technique with even higher precision than state-of-the-art IRMS. Thus, laser spectroscopy has the potential to contribute significantly to a better understanding of N turnover in soils, which is crucial for advancing strategies to mitigate emissions of this efficient greenhouse gas.
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Affiliation(s)
- Jan Reent Köster
- Institute of Plant Nutrition and Soil Science, Kiel University, Hermann-Rodewald-Str. 2, D-24118, Kiel, Germany.
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Schreiber F, Wunderlin P, Udert KM, Wells GF. Nitric oxide and nitrous oxide turnover in natural and engineered microbial communities: biological pathways, chemical reactions, and novel technologies. Front Microbiol 2012; 3:372. [PMID: 23109930 PMCID: PMC3478589 DOI: 10.3389/fmicb.2012.00372] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 09/28/2012] [Indexed: 12/20/2022] Open
Abstract
Nitrous oxide (N(2)O) is an environmentally important atmospheric trace gas because it is an effective greenhouse gas and it leads to ozone depletion through photo-chemical nitric oxide (NO) production in the stratosphere. Mitigating its steady increase in atmospheric concentration requires an understanding of the mechanisms that lead to its formation in natural and engineered microbial communities. N(2)O is formed biologically from the oxidation of hydroxylamine (NH(2)OH) or the reduction of nitrite (NO(-) (2)) to NO and further to N(2)O. Our review of the biological pathways for N(2)O production shows that apparently all organisms and pathways known to be involved in the catabolic branch of microbial N-cycle have the potential to catalyze the reduction of NO(-) (2) to NO and the further reduction of NO to N(2)O, while N(2)O formation from NH(2)OH is only performed by ammonia oxidizing bacteria (AOB). In addition to biological pathways, we review important chemical reactions that can lead to NO and N(2)O formation due to the reactivity of NO(-) (2), NH(2)OH, and nitroxyl (HNO). Moreover, biological N(2)O formation is highly dynamic in response to N-imbalance imposed on a system. Thus, understanding NO formation and capturing the dynamics of NO and N(2)O build-up are key to understand mechanisms of N(2)O release. Here, we discuss novel technologies that allow experiments on NO and N(2)O formation at high temporal resolution, namely NO and N(2)O microelectrodes and the dynamic analysis of the isotopic signature of N(2)O with quantum cascade laser absorption spectroscopy (QCLAS). In addition, we introduce other techniques that use the isotopic composition of N(2)O to distinguish production pathways and findings that were made with emerging molecular techniques in complex environments. Finally, we discuss how a combination of the presented tools might help to address important open questions on pathways and controls of nitrogen flow through complex microbial communities that eventually lead to N(2)O build-up.
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Affiliation(s)
- Frank Schreiber
- Department of Environmental Microbiology, Eawag - Swiss Federal Institute of Aquatic Science and Technology Dübendorf, Switzerland ; Department of Environmental Systems Sciences, Eidgenössische Technische Hochschule Zurich, Switzerland
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The Isotopomers of Nitrous Oxide: Analytical Considerations and Application to Resolution of Microbial Production Pathways. ADVANCES IN ISOTOPE GEOCHEMISTRY 2012. [DOI: 10.1007/978-3-642-10637-8_23] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Well R, Flessa H. Isotopologue enrichment factors of N(2)O reduction in soils. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:2996-3002. [PMID: 19681096 DOI: 10.1002/rcm.4216] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Isotopic signatures can be used to study sink and source processes of N(2)O, but the success of this approach is limited by insufficient knowledge on the isotope fractionation factors of the various reaction pathways. We investigated isotope enrichment factors of the N(2)O-to-N(2) step of denitrification (epsilon) in two arable soils, a silt-loam Haplic Luvisol and a sandy Gleyic Podzol. In addition to the epsilon of (18)O (epsilon(18O)) and of average (15)N (epsilon(bulk)), the epsilon of the (15)N site preference within the linear N(2)O molecule (epsilon(SP)) was also determined. Soils were anaerobically incubated in gas-tight bottles with N(2)O added to the headspace to induce N(2)O reduction. Pre-treatment included the removal of NO(3) (-) to prevent N(2)O production. Gas samples were collected regularly to determine the dynamics of N(2)O reduction, the time course of the isotopic signatures of residual N(2)O, and the associated isotope enrichment factors. To vary reduction rates and associated fractionation factors, several treatments were established including two levels of initial N(2)O concentration and anaerobic pre-incubation with or without addition of N(2)O. N(2)O reduction rates were affected by the soil type and initial N(2)O concentration. The epsilon(18O) and epsilon(bulk) ranged between -13 and -20 per thousand, and between -5 and -9 per thousand, respectively. Both quantities were more negative in the Gleyic Podzol. The epsilon of the central N position (epsilon(alpha)) was always larger than that of the peripheral N-position (epsilon(beta)), giving epsilon(SP) of -4 to -8 per thousand. The ranges and variation patterns of epsilon were comparable with those from previous static incubation studies with soils. Moreover, we found a relatively constant ratio between epsilon(18O) and epsilon(bulk) which is close to the default ratio of 2.5 that had been previously suggested. The fact that different soils exhibited comparable epsilon under certain conditions suggests that these values could serve to identify N(2)O reduction from the isotopic fingerprints of N(2)O emitted from any soil.
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Affiliation(s)
- R Well
- Johann Heinrich von Thünen-Institut, Federal Research Institute for Rural Areas, Forestry and Fisheries, Institute of Agricultural Climate Research, Bundesallee 50, 38116 Braunschweig, Germany.
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Well R, Flessa H. Isotopologue signatures of N2O produced by denitrification in soils. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jg000804] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- R. Well
- Büsgen Institute; Universität Göttingen; Göttingen Germany
| | - H. Flessa
- Institute of Agricultural Climate Research; Johann Heinrich von Thünen-Institut; Braunschweig Germany
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Griffith DWT, Parkes SD, Haverd V, Paton-Walsh C, Wilson SR. Absolute Calibration of the Intramolecular Site Preference of 15N Fractionation in Tropospheric N2O by FT-IR Spectroscopy. Anal Chem 2009; 81:2227-34. [DOI: 10.1021/ac802371c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David W. T. Griffith
- School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Stephen D. Parkes
- School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Vanessa Haverd
- School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Clare Paton-Walsh
- School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Stephen R. Wilson
- School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
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Kaiser J, Röckmann T. Correction of mass spectrometric isotope ratio measurements for isobaric isotopologues of O2, CO, CO2, N2O and SO2. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:3997-4008. [PMID: 19016255 DOI: 10.1002/rcm.3821] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Gas isotope ratio mass spectrometers usually measure ion current ratios of molecules, not atoms. Often several isotopologues contribute to an ion current at a particular mass-to-charge ratio (m/z). Therefore, corrections have to be applied to derive the desired isotope ratios. These corrections are usually formulated in terms of isotope ratios (R), but this does not reflect the practice of measuring the ion current ratios of the sample relative to those of a reference material. Correspondingly, the relative ion current ratio differences (expressed as delta values) are first converted into isotopologue ratios, then into isotope ratios and finally back into elemental delta values. Here, we present a reformulation of this data reduction procedure entirely in terms of delta values and the 'absolute' isotope ratios of the reference material. This also shows that not the absolute isotope ratios of the reference material themselves, but only product and ratio combinations of them, are required for the data reduction. These combinations can be and, for carbon and oxygen have been, measured by conventional isotope ratio mass spectrometers. The frequently implied use of absolute isotope ratios measured by specially calibrated instruments is actually unnecessary. Following related work on CO2, we here derive data reduction equations for the species O2, CO, N2O and SO2. We also suggest experiments to measure the required absolute ratio combinations for N2O, SO2 and O2. As a prelude, we summarise historic and recent measurements of absolute isotope ratios in international isotope reference materials.
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Affiliation(s)
- Jan Kaiser
- School of Environmental Sciences, University of East Anglia, Norwich, UK.
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31
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Well R, Flessa H. Isotope fractionation factors of N2O diffusion. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:2621-2628. [PMID: 18666201 DOI: 10.1002/rcm.3656] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Isotopic signatures of N2O are increasingly used to constrain the total global flux and the relative contribution of nitrification and denitrification to N2O emissions. Interpretation of isotopic signatures of soil-emitted N2O can be complicated by the isotopic effects of gas diffusion. The aim of our study was to measure the isotopic fractionation factors of diffusion for the isotopologues of N2O and to estimate the potential effect of diffusive fractionation during N2O fluxes from soils using simple simulations. Diffusion experiments were conducted to monitor isotopic signatures of N2O in reservoirs that lost N2O by defined diffusive fluxes. Two different mathematical approaches were used to derive diffusive isotope fractionation factors for 18O (epsilon18O), average 15N (epsilonbulk) and 15N of the central (alpha(-)) and peripheral (beta(-)) position within the linear N2O molecule (epsilon15Nalpha, epsilon15Nbeta). The measured epsilon18O was -7.79 +/- 0.27 per thousand and thus higher than the theoretical value of -8.7 per thousand. Conversely, the measured epsilonbulk (-5.23 +/- 0.27 per thousand) was lower than the theoretical value (-4.4 per thousand). The measured site-specific 15N fractionation factors were not equal, giving a difference between epsilon15Nalpha and epsilon15Nbeta (epsilonSP) of 1.55 +/- 0.28 per thousand. Diffusive fluxes of the N2O isotopologues from the soil pore space to the atmosphere were simulated, showing that isotopic signatures of N2O source pools and emitted N2O can be substantially different during periods of non-steady state fluxes. Our results show that diffusive isotope fractionation should be taken into account when interpreting natural abundance isotopic signatures of N2O fluxes from soils.
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Affiliation(s)
- Reinhard Well
- Soil Science of Temperate and Boreal Ecosystems, Buesgeninstitute, University of Göttingen, Büsgenweg 2, 37077 Göttingen, Germany.
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Baggs EM. A review of stable isotope techniques for N2O source partitioning in soils: recent progress, remaining challenges and future considerations. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:1664-1672. [PMID: 18435506 DOI: 10.1002/rcm.3456] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Nitrous oxide is produced in soil during several processes, which may occur simultaneously within different micro-sites of the same soil. Stable isotope techniques have a crucial role to play in the attribution of N(2)O emissions to different microbial processes, through estimation (natural abundance, site preference) or quantification (enrichment) of processes based on the (15)N and (18)O signatures of N(2)O determined by isotope ratio mass spectrometry. These approaches have the potential to become even more powerful when linked with recent developments in secondary isotope mass spectrometry, with microbial ecology, and with modelling approaches, enabling sources of N(2)O to be considered at a wide range of scales and related to the underlying microbiology. Such source partitioning of N(2)O is inherently challenging, but is vital to close the N(2)O budget and to better understand controls on the different processes, with a view to developing appropriate management practices for mitigation of N(2)O. In this respect, it is essential that as many of the contributing processes as possible are considered in any study aimed at source attribution, as mitigation strategies for one process may not be appropriate for another. To aid such an approach, here the current state of the art is critically examined, remaining challenges are highlighted, and recommendations are made for future direction.
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Affiliation(s)
- E M Baggs
- School of Biological Sciences (Plant & Soil Science), University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK.
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Yamagishi H, Westley MB, Popp BN, Toyoda S, Yoshida N, Watanabe S, Koba K, Yamanaka Y. Role of nitrification and denitrification on the nitrous oxide cycle in the eastern tropical North Pacific and Gulf of California. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jg000227] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ostrom NE, Pitt A, Sutka R, Ostrom PH, Grandy AS, Huizinga KM, Robertson GP. Isotopologue effects during N2O reduction in soils and in pure cultures of denitrifiers. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jg000287] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Westley MB, Popp BN, Rust TM. The calibration of the intramolecular nitrogen isotope distribution in nitrous oxide measured by isotope ratio mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:391-405. [PMID: 17216596 DOI: 10.1002/rcm.2828] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Two alternative approaches for the calibration of the intramolecular nitrogen isotope distribution in nitrous oxide using isotope ratio mass spectrometry have yielded a difference in the 15N site preference (defined as the difference between the delta15N of the central and end position nitrogen in NNO) of tropospheric N2O of almost 30 per thousand. One approach is based on adding small amounts of labeled 15N2O to the N2O reference gas and tracking the subsequent changes in m/z 30, 31, 44, 45 and 46, and this yields a 15N site preference of 46.3 +/- 1.4 per thousand for tropospheric N2O. The other involves the synthesis of N2O by thermal decomposition of isotopically characterized ammonium nitrate and yields a 15N site preference of 18.7 +/- 2.2 per thousand for tropospheric N2O. Both approaches neglect to fully account for isotope effects associated with the formation of NO+ fragment ions from the different isotopic species of N2O in the ion source of a mass spectrometer. These effects vary with conditions in the ion source and make it impossible to reproduce a calibration based on the addition of isotopically enriched N2O on mass spectrometers with different ion source configurations. These effects have a much smaller impact on the comparison of a laboratory reference gas with N2O synthesized from isotopically characterized ammonium nitrate. This second approach was successfully replicated and leads us to advocate the acceptance of the site preference value 18.7 +/- 2.2 per thousand for tropospheric N2O as the provisional community standard until further independent calibrations are developed and validated. We present a technique for evaluating the isotope effects associated with fragment ion formation and revised equations for converting ion signal ratios into isotopomer ratios.
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Affiliation(s)
- Marian B Westley
- Department of Oceanography, University of Hawaii, Honolulu, HI, USA
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Sutka RL, Ostrom NE, Ostrom PH, Breznak JA, Gandhi H, Pitt AJ, Li F. Distinguishing nitrous oxide production from nitrification and denitrification on the basis of isotopomer abundances. Appl Environ Microbiol 2006; 72:638-44. [PMID: 16391101 PMCID: PMC1352222 DOI: 10.1128/aem.72.1.638-644.2006] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intramolecular distribution of nitrogen isotopes in N2O is an emerging tool for defining the relative importance of microbial sources of this greenhouse gas. The application of intramolecular isotopic distributions to evaluate the origins of N2O, however, requires a foundation in laboratory experiments in which individual production pathways can be isolated. Here we evaluate the site preferences of N2O produced during hydroxylamine oxidation by ammonia oxidizers and by a methanotroph, ammonia oxidation by a nitrifier, nitrite reduction during nitrifier denitrification, and nitrate and nitrite reduction by denitrifiers. The site preferences produced during hydroxylamine oxidation were 33.5 +/- 1.2 per thousand, 32.5 +/- 0.6 per thousand, and 35.6 +/- 1.4 per thousand for Nitrosomonas europaea, Nitrosospira multiformis, and Methylosinus trichosporium, respectively, indicating similar site preferences for methane and ammonia oxidizers. The site preference of N2O from ammonia oxidation by N. europaea (31.4 +/- 4.2 per thousand) was similar to that produced during hydroxylamine oxidation (33.5 +/- 1.2 per thousand) and distinct from that produced during nitrifier denitrification by N. multiformis (0.1 +/- 1.7 per thousand), indicating that isotopomers differentiate between nitrification and nitrifier denitrification. The site preferences of N2O produced during nitrite reduction by the denitrifiers Pseudomonas chlororaphis and Pseudomonas aureofaciens (-0.6 +/- 1.9 per thousand and -0.5 +/- 1.9 per thousand, respectively) were similar to those during nitrate reduction (-0.5 +/- 1.9 per thousand and -0.5 +/- 0.6 per thousand, respectively), indicating no influence of either substrate on site preference. Site preferences of approximately 33 per thousand and approximately 0 per thousand are characteristic of nitrification and denitrification, respectively, and provide a basis to quantitatively apportion N2O.
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Affiliation(s)
- R L Sutka
- Department of Zoology, Michigan State University, East Lansing, Michigan, USA.
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37
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Distinguishing nitrous oxide production from nitrification and denitrification on the basis of isotopomer abundances. Appl Environ Microbiol 2006. [PMID: 16391101 DOI: 10.1128/aem.72.1.638?644.2006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intramolecular distribution of nitrogen isotopes in N2O is an emerging tool for defining the relative importance of microbial sources of this greenhouse gas. The application of intramolecular isotopic distributions to evaluate the origins of N2O, however, requires a foundation in laboratory experiments in which individual production pathways can be isolated. Here we evaluate the site preferences of N2O produced during hydroxylamine oxidation by ammonia oxidizers and by a methanotroph, ammonia oxidation by a nitrifier, nitrite reduction during nitrifier denitrification, and nitrate and nitrite reduction by denitrifiers. The site preferences produced during hydroxylamine oxidation were 33.5 +/- 1.2 per thousand, 32.5 +/- 0.6 per thousand, and 35.6 +/- 1.4 per thousand for Nitrosomonas europaea, Nitrosospira multiformis, and Methylosinus trichosporium, respectively, indicating similar site preferences for methane and ammonia oxidizers. The site preference of N2O from ammonia oxidation by N. europaea (31.4 +/- 4.2 per thousand) was similar to that produced during hydroxylamine oxidation (33.5 +/- 1.2 per thousand) and distinct from that produced during nitrifier denitrification by N. multiformis (0.1 +/- 1.7 per thousand), indicating that isotopomers differentiate between nitrification and nitrifier denitrification. The site preferences of N2O produced during nitrite reduction by the denitrifiers Pseudomonas chlororaphis and Pseudomonas aureofaciens (-0.6 +/- 1.9 per thousand and -0.5 +/- 1.9 per thousand, respectively) were similar to those during nitrate reduction (-0.5 +/- 1.9 per thousand and -0.5 +/- 0.6 per thousand, respectively), indicating no influence of either substrate on site preference. Site preferences of approximately 33 per thousand and approximately 0 per thousand are characteristic of nitrification and denitrification, respectively, and provide a basis to quantitatively apportion N2O.
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Distinguishing nitrous oxide production from nitrification and denitrification on the basis of isotopomer abundances. Appl Environ Microbiol 2006. [PMID: 16391101 DOI: 10.1128/aem.72.1.638‐644.2006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intramolecular distribution of nitrogen isotopes in N2O is an emerging tool for defining the relative importance of microbial sources of this greenhouse gas. The application of intramolecular isotopic distributions to evaluate the origins of N2O, however, requires a foundation in laboratory experiments in which individual production pathways can be isolated. Here we evaluate the site preferences of N2O produced during hydroxylamine oxidation by ammonia oxidizers and by a methanotroph, ammonia oxidation by a nitrifier, nitrite reduction during nitrifier denitrification, and nitrate and nitrite reduction by denitrifiers. The site preferences produced during hydroxylamine oxidation were 33.5 +/- 1.2 per thousand, 32.5 +/- 0.6 per thousand, and 35.6 +/- 1.4 per thousand for Nitrosomonas europaea, Nitrosospira multiformis, and Methylosinus trichosporium, respectively, indicating similar site preferences for methane and ammonia oxidizers. The site preference of N2O from ammonia oxidation by N. europaea (31.4 +/- 4.2 per thousand) was similar to that produced during hydroxylamine oxidation (33.5 +/- 1.2 per thousand) and distinct from that produced during nitrifier denitrification by N. multiformis (0.1 +/- 1.7 per thousand), indicating that isotopomers differentiate between nitrification and nitrifier denitrification. The site preferences of N2O produced during nitrite reduction by the denitrifiers Pseudomonas chlororaphis and Pseudomonas aureofaciens (-0.6 +/- 1.9 per thousand and -0.5 +/- 1.9 per thousand, respectively) were similar to those during nitrate reduction (-0.5 +/- 1.9 per thousand and -0.5 +/- 0.6 per thousand, respectively), indicating no influence of either substrate on site preference. Site preferences of approximately 33 per thousand and approximately 0 per thousand are characteristic of nitrification and denitrification, respectively, and provide a basis to quantitatively apportion N2O.
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Assonov SS, Brenninkmeijer CAM. On the N2O correction used for mass spectrometric analysis of atmospheric CO2. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2006; 20:1809-19. [PMID: 16676323 DOI: 10.1002/rcm.2516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
To obtain accurate values of delta(13)C(CO(2)) and delta(18)O(CO(2)) on environmental CO(2) by mass spectrometry, the raw isotope data must be corrected for the isobaric N(2)O contribution. This is one of the analytical problems limiting inter-laboratory delta(13)C(CO(2)) data consistency. The key parameter, the N(2)O relative ionisation efficiency (E(N2O)), cannot be determined with sufficient accuracy by direct measurements of pure N(2)O. The determination of (E(N2O)) by analyses on N(2)O--CO(2) mixtures of known isotope composition and mixing proportions has been recently suggested. In this work we propose a new method of N(2)O correction which uses the m/z 30 signal as a measure of the N(2)O/CO(2) ratio, so that determinations of (E(N2O)) and N(2)O content are not required. The method uses the fact that fragment-ion spectra of N(2)O and CO(2) are very specific. The formalism of the correction is considered. Various tests demonstrate that the new method is robust, stable and easy to implement in practice. The effective value (E(N2O)) (the key parameter for the new correction) has to be calibrated on known N(2)O--CO(2) mixtures by measuring (30)R signals only. The method accuracy we presently achieved is around 2.5% and any error which appears to come mostly from our N(2)O--CO(2) mixture preparation. Based on our tests and error considerations, the error of the proposed method that may be achieved is as low as +/-1.5% (relative to the correction magnitude). For tropospheric CO(2) this means +/-0.003 per thousand and +/-0.005 per thousand for delta(13)C(CO(2)) and delta(18)O(CO(2)), respectively. The proposed method may be valuable for small samples where no separate N(2)O determinations are available (e.g. ice core samples and CF-IRMS measurements) as well as for determination of (E(N2O)) and testing the 'traditional' N(2)O correction based on mass balance calculations.
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Affiliation(s)
- S S Assonov
- Max Planck Institute for Chemistry, P. O. Box 3060, 55020 Mainz, Germany.
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Well R, Flessa H, Jaradat F, Toyoda S, Yoshida N. Measurement of isotopomer signatures of N2O in groundwater. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jg000044] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- R. Well
- Institute of Soil Science and Forest Nutrition; University of Göttingen; Gottingen Germany
| | - H. Flessa
- Institute of Soil Science and Forest Nutrition; University of Göttingen; Gottingen Germany
| | - F. Jaradat
- Institute of Soil Science; University of Göttingen; Gottingen Germany
| | - S. Toyoda
- Department of Environmental Chemistry and Engineering; Tokyo Institute of Technology; Tokyo Japan
| | - N. Yoshida
- Department of Environmental Chemistry and Engineering; Tokyo Institute of Technology; Tokyo Japan
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Ogawa M, Yoshida N. Intramolecular distribution of stable nitrogen and oxygen isotopes of nitrous oxide emitted during coal combustion. CHEMOSPHERE 2005; 61:877-87. [PMID: 15993467 DOI: 10.1016/j.chemosphere.2005.04.096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2004] [Revised: 04/17/2005] [Accepted: 04/18/2005] [Indexed: 05/03/2023]
Abstract
The intramolecular distribution of stable isotopes in nitrous oxide that is emitted during coal combustion was analyzed using an isotopic ratio mass spectrometer equipped with a modified ion collector system (IRMS). The coal was combusted in a test furnace fitted with a single burner and the flue gases were collected at the furnace exit following removal of SO(x), NO(x), and H2O in order to avoid the formation of artifact nitrous oxide. The nitrous oxide in the flue gases proved to be enriched in 15N relative to the fuel coal. In air-staged combustion experiments, the staged air ratio was controlled over a range of 0 (unstaged combustion), 20%, and 30%. As the staged air ratio increased, the delta15N and delta18O of the nitrous oxide in the flue gases became depleted. The central nitrogen of the nitrous oxide molecule, N(alpha), was enriched in 15N relative to that occupying the end position of the molecule, N(beta), but this preference, expressed as delta15N(alpha)-delta15N(beta), decreased with the increase in the staged air ratio. Thermal decomposition and hydrogen reduction experiments carried out using a tube reactor allowed qualitative estimates of the kinetic isotope effects that occurred during the decomposition of the nitrous oxide and quantitative estimates of the extent to which the nitrous oxide had decomposed. The site preference of nitrous oxide increased with the extent of the decomposition reactions. Assuming that no site preference exists in nitrous oxide before decomposition, the behavior of nitrous oxide in the test combustion furnace was analyzed using the Rayleigh equation based on a single distillation model. As a result, the extent of decomposition of nitrous oxide was estimated as 0.24-0.26 during the decomposition reaction governed by the thermal decomposition and as 0.35-0.38 during the decomposition reaction governed by the hydrogen reduction in staged combustion. The intramolecular distribution of nitrous oxide can be a valuable parameter to estimate the extent of decomposition reaction and to understand the reaction pathway of nitrous oxide at the high temperature.
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Affiliation(s)
- Mitsuteru Ogawa
- Department of Environmental Chemistry and Engineering, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
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Röckmann T, Levin I. High-precision determination of the changing isotopic composition of atmospheric N2O from 1990 to 2002. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jd006066] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Park S. Measurements of N2O isotopologues in the stratosphere: Influence of transport on the apparent enrichment factors and the isotopologue fluxes to the troposphere. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jd003731] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Goldstein AH, Shaw SL. Isotopes of Volatile Organic Compounds: An Emerging Approach for Studying Atmospheric Budgets and Chemistry. Chem Rev 2003; 103:5025-48. [PMID: 14664642 DOI: 10.1021/cr0206566] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Allen H Goldstein
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720, USA.
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Brenninkmeijer CAM, Janssen C, Kaiser J, Röckmann T, Rhee TS, Assonov SS. Isotope Effects in the Chemistry of Atmospheric Trace Compounds. Chem Rev 2003; 103:5125-62. [PMID: 14664646 DOI: 10.1021/cr020644k] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sutka RL, Ostrom NE, Ostrom PH, Gandhi H, Breznak JA. Nitrogen isotopomer site preference of N2O produced by Nitrosomonas europaea and Methylococcus capsulatus Bath. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2003; 17:738-745. [PMID: 12661029 DOI: 10.1002/rcm.968] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The relative importance of individual microbial pathways in nitrous oxide (N(2)O) production is not well known. The intramolecular distribution of (15)N in N(2)O provides a basis for distinguishing biological pathways. Concentrated cell suspensions of Methylococcus capsulatus Bath and Nitrosomonas europaea were used to investigate the site preference of N(2)O by microbial processes during nitrification. The average site preference of N(2)O formed during hydroxylamine oxidation by M. capsulatus Bath (5.5 +/- 3.5 per thousand) and N. europaea (-2.3 +/- 1.9 per thousand) and nitrite reduction by N. europaea (-8.3 +/- 3.6 per thousand) differed significantly (ANOVA, f((2,35)) = 247.9, p = 0). These results demonstrate that the mechanisms for hydroxylamine oxidation are distinct in M. capsulatus Bath and N. europaea. The average delta(18)O-N(2)O values of N(2)O formed during hydroxylamine oxidation for M. capsulatus Bath (53.1 +/- 2.9 per thousand) and N. europaea (-23.4 +/- 7.2 per thousand) and nitrite reduction by N. europaea (4.6 +/- 1.4 per thousand) were significantly different (ANOVA, f((2,35)) = 279.98, p = 0). Although the nitrogen isotope value of the substrate, hydroxylamine, was similar in both cultures, the observed fractionation (delta(15)N) associated with N(2)O production via hydroxylamine oxidation by M. capsulatus Bath and N. europaea (-2.3 and 26.0 per thousand, respectively) provided evidence that differences in isotopic fractionation were associated with these two organisms. The site preferences in this study are the first measured values for isolated microbial processes. The differences in site preference are significant and indicate that isotopomers provide a basis for apportioning biological processes producing N(2)O.
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Affiliation(s)
- R L Sutka
- Department of Geological Sciences, Michigan State University, East Lansing, MI 48824, USA.
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Kaiser J. Complete and accurate mass spectrometric isotope analysis of tropospheric nitrous oxide. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2003jd003613] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Röckmann T, Kaiser J, Brenninkmeijer CAM, Brand WA. Gas chromatography/isotope-ratio mass spectrometry method for high-precision position-dependent 15N and 18O measurements of atmospheric nitrous oxide. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2003; 17:1897-1908. [PMID: 12876691 DOI: 10.1002/rcm.1132] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We describe an automated gas chromatography/isotope-ratio mass spectrometry (GC/IRMS) method for the determination of the (18)O and position-resolved (15)N content of nitrous oxide at natural isotope abundance. The position information is obtained from successive measurement of the isotopic composition of the N(2)O(+) ion at m/z 44, 45, 46 and the NO(+) fragment ion at m/z 30, 31. The fragment ion analysis is complicated by a non-linearity in the mass spectrometer that has to be taken into account. Evaluation of the absolute peak areas allows for a simultaneous determination of the N(2)O mixing ratio for atmospheric samples. Samples with mixing ratios ranging from a few nmol/mol up to the percent level can be analyzed using different sample inlet systems. The high concentration inlet system provides an easy and quick method to carry out various diagnostic tests, in particular to perform realistic linearity tests. A gas chromatographic set-up with a split column and a backflush possibility improves analytical precision and excludes interferences by substances with long retention times from preceding runs. We also describe a new open split interface that uses only a single transfer capillary to the mass spectrometer for sample and reference gas.
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Affiliation(s)
- Thomas Röckmann
- Max-Planck-Institut für Kernphysik, Bereich Atmosphärenphysik, Heidelberg, Germany.
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Kaiser J, Röckmann T, Brenninkmeijer CAM. Temperature dependence of isotope fractionation in N2O photolysis. Phys Chem Chem Phys 2002. [DOI: 10.1039/b204837j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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