Singly and doubly substituted isotopocules of nitrous oxide and their application
in environmental studies
Kristýna Kantnerová
Overview
2
introduction about N2O
QCLAS method
applications in our lab with singly substituted isotopologues
development for doubly substituted isotopologues
Introduction important trace gas
contribution by 6 % to global warming
depletion of stratospheric ozone
increasing atmospheric concentration, 328 ppb (2015)
3
anthropogenic sourcesnatural sources
4
NO2-NH3 NH2OH NO3
-
N2O
NO3- NO2
- NO N2O N2
ammonia-oxidizing bacteria (AOB)ammonia-oxidizing archaea (AOA) denitrifying bacteria
5
Aerobic environment
6
Anaerobic environment
Isotopic studies of N2O
αβ
isotopologue label abundance14N14N16O 446 9.903 x 10-1 the most abundant one14N15N16O 456 3.641 x 10-3
singly substituted15N14N16O 546 3.641 x 10-3
14N14N18O 448 1.986 x 10-3
14N14N17O 447 3.762 x 10-4
15N15N16O 556 1.339 x 10-5
multiply substituted
“clumped isotopes”
14N15N18O 458 7.300 x 10-6
15N14N18O 548 7.300 x 10-6
14N15N17O 457 1.383 x 10-6
15N14N17O 547 1.383 x 10-6
15N15N18O 558 2.684 x 10-8
15N15N17O 557 5.085 x 10-9
7
SP 446
446
1
15N site preference
Isotopic studies of N2O
8
Keeling plots
9
IRMS tradition
Molecular spectroscopy
10
laser
detector
HCl
figure adaptedfrom Jana Jágerská
mid-IR light
HCl
spectrum
Isotopes in molecular spectroscopy
11
H35ClH37Cl 35Cl : 37Cl = 3 : 1
line strengths from HITRAN2012, spectrum simulated using program from http://faculty.evansville.edu/bl22/simul.html
reduced mass
N2O ro-vibrational spectra
12 446 and singly substituted – HITRAN2012clumped – simulations in PGOPHER based on spectroscopic constants from Amiot 1976, Toth 1991, Wang et al. 2009 and Jun-he Du et al. 2011
99.03 %
0.364 %
0.364 %
0.198 %
0.37 ‰
13.2 permeg
7.2 permeg
7.2 permeg
Analytical technique (TREX-QCLAS)
13
Singly substituted isotopocules
14
laser
Field study #1 – southern Germany
15
Fendt
PhD project – Erkan Ibraim
Field study #1 – southern Germany
16
June – August 2016 intensively managed grassland research site local N2O fluxes, meteo and wind observation
mobile lab2 m sampleinlet
PhD project – Erkan Ibraim
Field study #2 – central Switzerland
17
Beromünster
PhD project – Erkan Ibraim
Field study #2 – central Switzerland
18
September – December 2017 in central Switzerland intensively managed grassland research site TREX-QCLAS using flux chambers
PhD project – Erkan Ibraim
Study #3 – high-altitude station Jungfraujoch
19
Jungfraujoch
Eliza Harris & Longfei Yu
Study #3 – high-altitude station Jungfraujoch
20
identification of seasonal variability since April 2014, ongoing stratosphere-troposhere exchange observable
Eliza Harris & Longfei Yu
Clumped isotopes in N2O
21
clumping thermodynamically favored
isotopologue label abundance14N14N16O 446 9.903 x 10-1
14N15N16O 456 3.641 x 10-3
15N14N16O 546 3.641 x 10-3
14N14N18O 448 1.986 x 10-3
14N14N17O 447 3.762 x 10-4
15N15N16O 556 1.339 x 10-5
14N15N18O 458 7.300 x 10-6
15N14N18O 548 7.300 x 10-6
reproduced using data and information from Wang et al. 2004, for population having ratio of isotopes equal to reference standards AIR-N2 and VSMOW
Clumped isotopes in N2O – IRMS
22
Thermo Scientific™ 253 Ultra™
nominal mass isotopologue label abundance
4614N14N18O 448 1.986 x 10-3
15N15N16O 556 1.339 x 10-5
4714N15N18O 458 7.3 x 10-6
15N14N18O 548 7.3 x 10-6
23
Clumped isotopes in N2O
99.03 %
0.364 %
0.364 %
0.198 %
0.37 ‰
13.2 permeg
7.2 permeg
7.2 permeg
446 and singly substituted – HITRAN2012clumped – simulations in PGOPHER based on spectroscopic constants from Amiot 1976, Toth 1991, Wang et al. 2009 and Jun-he Du et al. 2011
New reference scale for clumped N2O
24
equilibration of N2O – driving into stochastic (random) distribution
different temperatures – different equilibrium composition, calculated using statistical thermodynamics predictions
1 ∙ 1000 ‰) reference – stochastic (random) distribution
reproduced using data and information from Wang et al. 2004, for population having ratio of isotopes equal to reference standards AIR-N2 and VSMOW
Summary
25
TREX-QCLAS for singly substituted isotopologues
selective and precise analysis of clumped isotopes
a new reference isotopic scale has been developed
Outlook
applications for clumped N2O isotopic signatures from pure microbial cultures
NO2-NH3 NH2OH NO3
-
N2O
NO2- NO
N2O
N2
nitrification denitrification- bacterial- fungal
Acknowledgement
26
Joachim Mohn – supervisor at Empa Dübendorf
Stefano Bernasconi – supervisor at ETH Zürich
lab people – Kerstin Zeyer, Sarah Eggleston, Erkan Ibraim, Longfei Yu, Béla Tuzson, Lukas Emmenegger
27
Thank you for the attention!
Used figures
28
https://www.roboticsbusinessreview.com/wp-content/uploads/2014/05/agriculture-robot.jpg
http://www.motherearthnews.com/-/media/Images/MEN/Editorial/Articles/Magazine-Articles/2016/04-01/The-Benefits-of-Earthworms-and-How-to-Attract-Them/soil-and-worm-jpg.jpg
https://images.designtrends.com/wp-content/uploads/2016/02/24090853/Ocean-Wave-Dolphins-Wallpaper.jpg
https://www.kullabs.com/uploads/industry.jpg
http://constantine.typepad.com/.a/6a0120a7fc3be9970b01a73d8a8038970d-pi
https://www.kwl.ca/sites/default/files/03_0.jpg
http://www2.ess.ucla.edu/~schauble/MoleculeHTML/N2O_html/N2O_nu3.gif
https://www.philpoteducation.com/pluginfile.php/1363/mod_book/chapter/1333/14.2.6b.jpg