Dr. Axel Horst

Contact / Addess:

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Phone +49 (0) 341 235 1005
Fax +49 (0) 341 235 450822


Helmholtz Centre for Environmental Research - UFZ
Permoserstrasse 15
04318 Leipzig

Dr. Axel Horst

Current Project


The stratospheric ozone layer is an important shield to protect life on earth. Most of the short-waved UVB and all UVC radiation is absorbed which otherwise would cause skin cancer and genetic damage. Destruction of the ozone layer by halogen radicals was discovered in the 1970s and consequently production of many halogenated compounds was curtailed. Methyl chloride (CH3Cl) and methyl bromide (CH3Br), important contributors of halogens in the stratosphere, are emitted by both natural and anthropogenic sources but significant gaps remain in the calculated atmospheric budget due to uncertainties concerning formation mechanisms and/or overestimation of degradation processes. In this project a conceptual framework will be developed to apply multi-element isotope analysis (2H, 13C, 81Br, 37Cl) for delineating sources and sinks of methyl halides. The specific aim is to isotopically identify and characterize oxidation of methyl halides by hydroxyl radicals, the main degradation process, both to understand the fate of these important pollutants in the environment but foremost to resolve the impact on any future isotope based approach for source apportionment.

This project is funded by a Marie - Skłodowska - Curie postdoctoral fellowship (individual fellowship; 701315; H2020-MSCA-IF- 2015 DEMETROPIS)


Curriculum Vitae


present
2016
Postdoctoral Fellow
Helmholtz Centre for Environmental Research – UFZ
Department of Isotope Biogeochemistry
2016
2013
Postdoctoral Fellow
University of Toronto, Earth Sciences, Toronto, Canada
2013
2008
Doctoral degree (Ph.D.)
Deptartment of Applied Environmental Science (ITM), Stockholm University, Sweden
2008
2006
Research assistant
Centro de Estudios del Agua, Instituto Tecnológico y de Estudios Superiores Monterrey (ITESM), Monterrey, Mexico
2006
2000
Diplom (Master)
Technische Universität Bergakademie Freiberg, Germany

Publications

Horst A., Renpenning J., Richnow H.-H. and Gehre M. (2017), Compound specific stable chlorine isotope analysis of volatile aliphatic compounds using gas chromatography hyphenated with multiple collector inductively coupled plasma mass spectrometry, Analytical Chemistry, Vol 89 (17), pp 9131-9138, full text (open access)

Horst, A., Lacrampe-Couloume G. and Sherwood Lollar B. (2016): Vapor pressure isotope effects in halogenated organic compounds and alcohols dissolved in water, Analytical Chemistry, Vol 88 (24), pp 12066−12071                 

Thornton, B. F., Horst A., Carrizo D., Holmstrand H. (2016), Methyl chloride and methyl bromide emissions from baking: an unrecognized anthropogenic source, Science of the Total Environment, Vol 551-552:327-33

Horst, A., Lacrampe-Couloume G. and Sherwood Lollar B. (2015): Compound-specific stable carbon isotope analysis of chlorofluorocarbons in groundwater, Analytical Chemistry, Vol 87 (20), pp 10498–10504

Horst A., Andersson P., Thornton B. F., Holmstrand H., Wishkerman A., Keppler F., and Gustafsson O. (2014), Stable bromine isotopic composition of methyl bromide released from plant matter, Geochimica et Cosmochimica Acta, Vol 125, 186-195

Horst A., Thornton B. F., Holmstrand H., Andersson P., Crill P. M., and Gustafsson O. (2013), Stable bromine isotopic composition of atmospheric CH3Br, Tellus B, Vol 65, p. 1-8

Thornton, B. F., Horst A., Carrizo D., Holmstrand H., Andersson P., Crill P. M., and Gustafsson O. (2013), A high-volume cryosampler and sample purification system for halogen isotope studies of methyl halides, Journal of Atmospheric and Oceanic Technology Vol 30, Iss 9, p. 2095-2107

Horst A., Holmstrand H., Andersson P., Andersson A., Carrizo D., Thornton B. F., and Gustafsson O. (2011), Compound-specific bromine isotope analysis of methyl bromide using gas chromatography hyphenated with inductively coupled plasma multiple-collector mass spectrometry, Rapid Communications in Mass Spectrometry, Vol. 25(17), p. 2425–2432,

Horst A., Mahlknecht J., López-Zavala M.A., Mayer B. (2011): The origin of salinity and sulphate contamination of groundwater in the Colima State, Mexico, constrained by stable isotopes. Environmental Earth Sciences Vol 64 (7), p. 1931-1941.

Horst A., Mahlknecht J., Merkel B., Aravena R., Ramos-A. Y.R (2008): Evaluation of recharge processes and the impacts of irrigation on groundwater by using CFCs and radiogenic isotopes in the Silao-Romita basin, Mexico. Hydrogeology Journal Vol.16 (8), p.1601-1614

Mahlknecht J., Horst A., Hernandez-Limon L.G., Aravena R. (2008): Groundwater geochemistry of the Chihuahua City region in the Rio Conchos Basin (Northern Mexico). Hydrological Processes Vol 22 (24) p. 4736 - 4751

Horst A., Mahlknecht J., Merkel B. (2007): Estimating groundwater mixing and origin in an overexploited aquifer in Guanajuato, Mexico using stable isotopes (strontium-87, carbon-13, deuterium, oxygen-18). Isotopes in Environmental and Health Studies Vol 43 (4). p. 323-338
                                               

Theses

Ph.D thesis: Stable bromine isotopic composition of methyl bromide - Method development and applications

M.Sc. thesis: Use of stable and radioactive isotopes and gaseous tracers for estimating groundwater recharge, time of residence, mixing of the different types of groundwater and origin in the Silao Romita Aquifer, Guanajuato, Mexico