Biogeochemie Publikationen

2025

• Römer, Philipp Caspar Marie ; Wieland, Anna ; Torbenson, Max C. A. ; Reinig, Frederick ; Ziaco, Emanuele ; Frigo, Davide ; Greule, Markus ; Urban, Otmar ; Čáslavský, Josef ; u. a.: Covariance and climate signals among state-of-the-art tree-ring proxies. In: Quaternary science reviews Bd. 355. Amsterdam [u.a.], Elsevier (2025), S. 1–15

2024

• Cox, Terry ; Wieland, Anna ; Greule, Markus ; Keppler, Frank ; Einbock, Annika ; Alewell, Christine: Isotopic analysis (δ13C and δ2H) of lignin methoxy groups in forest soils to identify and quantify lignin sources. In: The science of the total environment Bd. 949. Amsterdam [u.a.], Elsevier Science (2024), S. 1–10
• Jardine, Kolby ; Gallo, Luiza ; Roth, Melissa ; Upadhyaya, Shivani ; Northen, Trent ; Kosina, Suzanne ; Tcherkez, Guillaume ; Eudes, Aymerick ; Domigues, Tomas ; u. a.: The „photosynthetic C1 pathway“ links carbon assimilation and growth in California poplar. In: Communications biology Bd. 7. London, Springer Nature (2024), S. 1–19
• Greule, Markus ; Le, Phuong Mai ; Meija, Juris ; Mester, Zoltán ; Keppler, Frank: Comparison of carbon isotope ratio measurement of the vanillin methoxy group by gc-irms and 13c-qnmr. In: Journal of the American Society for Mass Spectrometry Bd. 35. Washington, DC ; Amsterdam ; New York, ACS Publications ; Elsevier Science ; Springer (2024), Nr. 3, S. 100–105
• Schmitt, Fabian ; Schmitt, Axel Karl ; Scholz, Christian ; Keppler, Frank: High index reflective glass beads in modern river sediments as a potential marker for the Anthropocene. In: Newsletters on stratigraphy Bd. 57. Stuttgart, Borntraeger (2024), Nr. 2, S. 225–234
• Wieland, Anna ; Römer, Philipp ; Torbenson, Max ; Greule, Markus ; Urban, Otmar ; Čáslavský, Josef ; Pernicová, Natálie ; Trnka, Miroslav ; Büntgen, Ulf ; u. a.: Tree-ring stable isotopes in cellulose and lignin methoxy groups reveal different age-related behaviour. In: Quaternary international Bd. 693. Amsterdam [u.a.], Elsevier Science (2024), S. 38–48
• Cox, Terry ; Laceby, J. Patrick ; Greule, Markus ; Keppler, Frank ; Alewell, Christine: Using stable carbon isotopes of lignin-derived methoxy to improve historical apportionments of particulate organic matter and sediment sources incorporating multiple Suess corrections. In: Journal of soils and sediments Bd. 24. Berlin ; Heidelberg ; Landsberg ; Landsberg, Springer ; Ecomed Publ. ; Springer (2024), Nr. 5, S. 2159–2179

2023

• Hartmann, Simon Christoph ; Keppler, Frank ; Greule, Markus ; Lauer, Rebekka ; Horst, Axel: Triple-element stable isotope analysis of chloromethane emitted by royal fern and degraded by club moss. In: Journal of geophysical research Bd. 128. Hoboken, NJ, Wiley (2023), Nr. 5, S. 1–15
• Klintzsch, Thomas ; Geisinger, Hannah Katharina ; Wieland, Anna ; Langer, Gerald ; Nehrke, Gernot ; Bižić, Mina ; Greule, Markus ; Lenhart, Katharina ; Borsch, Christian ; u. a.: Stable carbon isotope signature of methane released from phytoplankton [research data].
• Klintzsch, Thomas ; Geisinger, Hannah Katharina ; Wieland, Anna ; Langer, G. ; Nehrke, G. ; Bizic, M. ; Greule, Markus ; Lenhart, Katharina ; Borsch, C. ; u. a.: Stable carbon isotope signature of methane released from phytoplankton. In: Geophysical research letters Bd. 50. Hoboken, NJ ; Washington, DC, Wiley ; American Geophysical Union (2023), Nr. 12, S. 1–12
• Meier, Thomas ; Keppler, Frank ; Mager, Ute ; Platt, Ulrich ; Reents, Friederike: Vorwort. Heidelberg : Universitätsbibliothek Heidelberg, 2023
• Reinig, Frederick ; Wacker, Lukas ; Jöris, Olaf ; Oppenheimer, Clive ; Guidobaldi, Giulia ; Nievergelt, Daniel ; Adolphi, Florian ; Cherubini, Paolo ; Engels, Stefan ; u. a.: Reply to: Possible magmatic CO2 influence on the Laacher See eruption date. Bd. 619. London [u.a.] ; London : Nature Publ. Group ; Macmillan, 2023
• Schorndorf, Nils ; Frank, Norbert ; Ritter, Simon M. ; Warken, Sophie F. ; Scholz, Christian ; Keppler, Frank ; Scholz, Denis ; Weber, Michael ; Aviles Olguin, Jeronimo ; u. a.: Mid- to late Holocene sea-level rise recorded in Hells Bells 234U/238U ratio and geochemical composition. In: Scientific reports Bd. 13. [London] ; London, Springer Nature ; Nature Publishing Group (2023), S. 1–11
• Polag, Daniela ; Keppler, Frank: Effect of immune responses on breath methane dynamics. In: Journal of breath research Bd. 17. Bristol, IOP (2023), Nr. 4, S. ?
• Hädeler, Jonas ; Velmurugan, Gunasekaran ; Lauer, Rebekka ; Radhamani, Rejith ; Keppler, Frank ; Comba, Peter: Natural abiotic iron-oxido-mediated formation of C1 and C2 compounds from environmentally important methyl-substituted substrates. In: Journal of the American Chemical Society Bd. 145. Washington, DC ; Washington, DC, ACS Publications ; American Chemical Society (2023), Nr. 45, S. 24590–24602
• Schroll, Moritz ; Liu, Liu ; Einzmann, Teresa ; Keppler, Frank ; Grossart, Hans-Peter: Methane accumulation and its potential precursor compounds in the oxic surface water layer of two contrasting stratified lakes. In: The science of the total environment Bd. 903. Amsterdam [u.a.], Elsevier Science (2023), S. 1–14
• Lu, Qiangqiang ; Liu, Xiaohong ; Treydte, Kerstin ; Greule, Markus ; Wieland, Anna ; Liu, Jinzhao ; Zhao, Liangju ; Zhang, Yu ; Kang, Huhu ; u. a.: Altitude-specific differences in tree-ring δ2H records of wood lignin methoxy in the Qinling mountains, central China. In: Quaternary science reviews Bd. 300. Amsterdam [u.a.], Elsevier (2023), S. 1–14
• Ernst, Leonard ; Barayeu, Uladzimir ; Hädeler, Jonas ; Dick, Tobias P. ; Klatt, Judith M. ; Keppler, Frank ; Rebelein, Johannes G.: Methane formation driven by light and heat prior to the origin of life and beyond. In: Nature Communications Bd. 14. [London] ; [London], Springer Nature ; Nature Publishing Group UK (2023), S. 1–10
• Sapper, Sarah Elise ; Jorgensen, Christian Juncher ; Schroll, Moritz ; Keppler, Frank ; Christiansen, Jesper Riis: Methane emissions from subglacial meltwater of three alpine glaciers in yukon, canada. In: Arctic, antarctic, and alpine research Bd. 55. London ; Boulder, Colo., Taylor & Francis Group ; Inst. (2023), Nr. 1, S. 1–13

2022

• Jungmann, Maximilian ; Vardag, Sanam Noreen ; Kutzner, Florian ; Keppler, Frank ; Schmidt, Martina ; Aeschbach, Nicole ; Gerhard, Ulrike ; Zipf, Alexander ; Lautenbach, Sven ; u. a.: Zooming-in for climate action: hyperlocal greenhouse gas data for mitigation action? In: Climate action Bd. 1. [Cham], Springer International Publishing (2022), S. 1–8
• Einzmann, Teresa ; Schroll, Moritz ; Kleint, Jan F. ; Greule, Markus ; Keppler, Frank: Application of concentration and 2-dimensional stable isotope measurements of methane to constrain sources and sinks in a seasonally stratified freshwater lake [data].
• Einzmann, Teresa ; Schroll, Moritz ; Kleint, Jan F. ; Greule, Markus ; Keppler, Frank: Application of concentration and 2-dimensional stable isotope measurements of methane to constrain sources and sinks in a seasonally stratified freshwater lake. In: Frontiers in Environmental Science Bd. 10. Lausanne, Frontiers Media (2022), S. 1–22
• Schroll, Moritz ; Lenhart, Katharina ; Greiner, Steffen ; Keppler, Frank: Making plant methane formation visible: insights from application of 13C-labeled dimethyl sulfoxide. In: Plant-environment interactions Bd. 3. Hoboken, NJ, Wiley (2022), Nr. 3, S. 104–117
• Kirchhoff, Thomas ; Keppler, Frank ; Meier, Thomas ; Lorenzen, Jacqueline ; Granzow, Tanja: Umweltwissenschaften. Heidelberg : Universitätsbibliothek Heidelberg, 2022
• Schroll, Moritz ; Lenhart, Katharina ; Greiner, Steffen ; Keppler, Frank: Making plant methane formation visible - insights from application of 13C-labelled dimethyl sulfoxide [research data].
• Schlaudt, Oliver ; Bubenzer, Olaf ; Gebhardt, Hans ; Keppler, Frank ; Lorenzen, Jacqueline ; Reents, Friederike: Anthropozän. Heidelberg : Universitätsbibliothek, 2022
• Ernst, Leonard ; Steinfeld, Benedikt ; Barayeu, Uladzimir ; Klintzsch, Thomas ; Kurth, Markus ; Grimm, Dirk ; Dick, Tobias P. ; Rebelein, Johannes G. ; Bischofs-Pfeifer, Ilka ; u. a.: Methane formation driven by reactive oxygen species across all living organisms. Bd. 603. London [u.a.] ; London : Nature Publ. Group ; Macmillan, 2022
• Porter, Trevor J. ; Anhäuser, Tobias ; Halfar, Jochen ; Keppler, Frank ; Csank, Adam Z. ; Williams, Christopher J.: Canadian arctic Neogene temperatures reconstructed from hydrogen isotopes of lignin-methoxy groups from sub-fossil wood. In: Paleoceanography and paleoclimatology Bd. 37. Hoboken, NJ, Wiley (2022), Nr. 2, S. 1–16
• Keppler, Frank ; Schmitt, Axel Karl ; Trieloff, Mario: Geowissenschaften. Heidelberg : Universitätsbibliothek Heidelberg, 2022
• Wieland, Anna ; Greule, Markus ; Roemer, Philipp ; Esper, Jan ; Keppler, Frank: Climate signals in stable carbon and hydrogen isotopes of lignin methoxy groups from southern German beech trees. In: Climate of the past Bd. 18. Katlenburg-Lindau, Copernicus Ges. (2022), Nr. 8, S. 1849–1866
• Wieland, Anna ; Greule, Markus ; Roemer, Philipp ; Esper, Jan ; Keppler, Frank: Climate signals in stable carbon and hydrogen isotopes of lignin methoxy groups from southern German beech trees [data].
• Lu, Qiangqiang ; Liu, Xiaohong ; Tan, Liangcheng ; Keppler, Frank ; Treydte, Kerstin ; Wieland, Anna ; Zhang, Lingnan ; Shi, Xinwei ; Zhang, Yu ; u. a.: Tree-ring δ2H records of lignin methoxy indicate spring temperature changes since 20th century in the Qinling Mountains, China. In: Dendrochronologia Bd. 76. [Amsterdam] ; Jena, Elsevier ; Urban & Fischer (2022), S. 1–11

2021

• Greule, Markus ; Wieland, Anna ; Keppler, Frank: Measurements and applications of δ2H values of wood lignin methoxy groups for paleoclimatic studies. In: Quaternary science reviews Bd. 268. Amsterdam [u.a.], Elsevier (2021), S. 1–9
• Kröber, Eileen ; Wende, Sonja ; Kanukollu, Saranya ; Buchen-Tschiskale, Caroline ; Besaury, Ludovic ; Keppler, Frank ; Vuilleumier, Stéphane ; Kolb, Steffen ; Bringel, Françoise: 13C-chloromethane incubations provide evidence for novel bacterial chloromethane degraders in a living tree fern. In: Environmental microbiology Bd. 23. Oxford [u.a.] ; Oxford, Blackwell ; Blackwell Science (2021), Nr. 8, S. 4450–4465
• Keppler, Frank: A surprise from the deep: isotope patterns of methoxyl groups reveal the origin and production potential of methane from coal. In: Science. Bd. 374. Washington, DC [u.a.] : American Association for the Advancement of Science, 2021, S. 821–822
• Jakob, Kim ; Ho, S. Ling ; Meckler, A. Nele ; Pross, Jörg ; Fiebig, Jens ; Keppler, Frank ; Friedrich, Oliver: Stable biological production in the Eastern Equatorial Pacific Across the Plio-Pleistocene transition (∼3.35-2.0 Ma). In: Paleoceanography and paleoclimatology Bd. 36. Hoboken, NJ, Wiley (2021), Nr. 4, S. 1–16
• Kleint, Jan F. ; Wellach, Yannic ; Schroll, Moritz ; Keppler, Frank ; Isenbeck-Schröter, Margot: The impact of seasonal sulfate-methane transition zones on methane cycling in a sulfate-enriched freshwater environment. In: Limnology and oceanography Bd. 66. Oxford [u.a.] ; Waco, Tex., Wiley-Blackwell ; ASLO (2021), Nr. 6, S. 2290–2308
• Wieland, Anna ; Greule, Markus ; Roemer, Philipp ; Esper, Jan ; Keppler, Frank: Climate signals in stable carbon and hydrogen isotopes of lignin methoxy groups from southern German beech trees. In: Climate of the past discussions. Katlenburg-Lindau, Copernicus Ges. (2021), S. 1–26

2020

• Bižić, Mina ; Klintzsch, Thomas ; Keppler, Frank: Aquatic and terrestrial cyanobacteria produce methane. In: Science advances Bd. 6. Washington, DC [u.a.], Assoc. (2020), Nr. 3
• Kleint, Jan F. ; Günthel, Marco ; Klintzsch, Thomas ; Kirillin, Georgiy ; Grossart, Hans-Peter ; Keppler, Frank ; Isenbeck-Schröter, Margot: High spatiotemporal dynamics of methane production and emission in oxic surface water. In: Environmental science & technology Bd. 54. Columbus, Ohio, American Chemical Society (2020), Nr. 3, S. 1451–1463
• Greule, Markus ; Moossen, Heiko ; Lloyd, Max K. ; Geilmann, Heike ; Brand, Willi A. ; Eiler, John M. ; Qi, Haiping ; Keppler, Frank: Three wood isotopic reference materials for [delta]2H and [delta]13C measurements of plant methoxy groups. In: Chemical geology Bd. 533. New York, NY [u.a.], Elsevier (2020)
• Keppler, Frank ; Barnes, Jaime D. ; Horst, Axel ; Bahlmann, Enno ; Luo, Jing ; Nadalig, Thierry ; Greule, Markus ; Hartmann, Simon Christoph ; Vuilleumier, Stéphane: Chlorine isotope fractionation of the major chloromethane degradation processes in the environment. In: Environmental science & technology letters Bd. 54. Columbus, Ohio, ACS (2020), Nr. 3, S. 1634–1645
• Anhäuser, Tobias ; Sehls, Birgit ; Thomas, Werner ; Hartl, Claudia ; Greule, Markus ; Scholz, Denis ; Esper, Jan ; Keppler, Frank: Tree-ring [delte]2H values from lignin methoxyl groups indicate sensitivity to European-scale temperature changes. In: Palaeogeography, palaeoclimatology, palaeoecology Bd. 546. Amsterdam [u.a.], Elsevier Science (2020)
• Keppler, Frank ; Röhling, Amelie Ninja ; Jäger, Nicole ; Schroll, Moritz ; Hartmann, Simon Christoph ; Greule, Markus: Sources and sinks of chloromethane in a salt marsh ecosystem: constraints from concentration and stable isotope measurements of laboratory incubation experiments. In: Environmental science Bd. 22. Cambridge, RSC Publ. (2020), Nr. 3, S. 627–641
• Schroll, Moritz ; Keppler, Frank ; Greule, Markus ; Eckhardt, Christian ; Zorn, Holger ; Lenhart, Katharina: The stable carbon isotope signature of methane produced by saprotrophic fungi. In: Biogeosciences Bd. 17. Katlenburg-Lindau [u.a.], Copernicus (2020), Nr. 14, S. 3891–3901
• Schroll, Moritz ; Keppler, Frank ; Greule, Markus ; Eckhardt, Christian ; Zorn, Holger ; Lenhart, Katharina: The stable carbon isotope signature of methane produced by saprotrophic fungi [dataset].
• Schroll, Moritz ; Keppler, Frank ; Greule, Markus ; Eckhardt, Christian ; Zorn, Holger ; Lenhart, Katharina: The stable carbon isotope signature of methane produced by saprotrophic fungi. In: Biogeosciences discussions. Katlenburg-Lindau [u.a.], Copernicus (2020), S. 1–21
• Klintzsch, Thomas ; Langer, Gerald ; Wieland, Anna ; Geisinger, Hannah Katharina ; Lenhart, Katharina ; Nehrke, Gernot ; Keppler, Frank: Effects of temperature and light on methane production of widespread marine phytoplankton. In: Journal of geophysical research Bd. 125. Hoboken, NJ, Wiley (2020), Nr. 9
• Klintzsch, Thomas ; Keppler, Frank: Effects of temperature and light on methane production of widespread marine phytoplankton [dataset].
• Wang, Yabo ; Liu, Xiaohong ; Anhäuser, Tobias ; Lu, Qiangqiang ; Zeng, Xiaomin ; Zhang, Qiuliang ; Wang, Keyi ; Zhang, Lingnan ; Zhang, Yu ; u. a.: Temperature signal recorded in δ2H and δ13C values of wood lignin methoxyl groups from a permafrost forest in northeastern China. In: The science of the total environment Bd. 727. Amsterdam [u.a.], Elsevier Science (2020), S. 1–10
• Lu, Qiangqiang ; Liu, Xiaohong ; Anhäuser, Tobias ; Keppler, Frank ; Wang, Yabo ; Zeng, Xiaomin ; Zhang, Qiuliang ; Zhang, Lingnan ; Wang, Keyi ; u. a.: Tree-ring lignin proxies in Larix gmelinii forest growing in a permafrost area of northeastern China: temporal variation and potential for climate reconstructions. In: Ecological indicators Bd. 118. Amsterdam [u.a.], Elsevier Science (2020)

2019

• Greule, Markus ; Keppler, Frank: Methyl sulfates as methoxy isotopic reference materials for [delta]13C and [delta]2H measurements. In: Rapid communications in mass spectrometry Bd. 33. New York, NY, Wiley Interscience (2019), Nr. 4, S. 343–350
• Lenhart, Katharina ; Greiner, Steffen ; Keppler, Frank: Nitrous oxide effluxes from plants as a potentially important source to the atmosphere. In: The new phytologist Bd. 221. Oxford [u.a.] ; Oxford ; Oxford [u.a.], Wiley-Blackwell ; Blackwell Science ; Blackwell (2019), Nr. 3, S. 1398–1408
• Klintzsch, Thomas ; Keppler, Frank: Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment [dataset].
• Ritter, Simon M. ; Isenbeck-Schröter, Margot ; Scholz, Christian ; Keppler, Frank ; Klose, Lukas ; Schorndorf, Nils ; Stinnesbeck, Wolfgang: Subaqueous speleothems (Hells Bells) formed by the interplay of pelagic redoxcline biogeochemistry and specific hydraulic conditions in the El Zapote sinkhole, Yucatán Peninsula, Mexico. In: Biogeosciences Bd. 16. Katlenburg-Lindau [u.a.], Copernicus (2019), Nr. 11, S. 2285–2305
• Polag, Daniela ; Keppler, Frank: Global methane emissions from the human body: past, present and future. In: Atmospheric environment Bd. 214. Amsterdam [u.a.], Elsevier Science (2019)
• Liu, Jiangong ; Hartmann, Simon Christoph ; Keppler, Frank: Simultaneous abiotic production of greenhouse gases (CO2, CH4, and N2O) in subtropical soils. In: Journal of geophysical research Bd. 124. Hoboken, NJ, Wiley (2019), Nr. 7, S. 1977–1987
• Bringel, Françoise ; Besaury, Ludovic ; Keppler, Frank: Methylotrophs and methylotroph populations for chloromethane degradation. In: Current issues in molecular biology Bd. 33. Wymondham, Norfolk, [Verlag nicht ermittelbar] (2019), S. 149–172
• Klintzsch, Thomas ; Langer, Gerald ; Nehrke, Gernot ; Wieland, Anna ; Lenhart, Katharina ; Keppler, Frank: Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment. In: Biogeosciences Bd. 16. Katlenburg-Lindau [u.a.], Copernicus (2019), Nr. 20, S. 4129–4144
• Bahlmann, Enno ; Keppler, Frank ; Greule, Markus ; Schöler, Heinz Friedrich: Evidence for a major missing source in the global chloromethane budget from stable carbon isotopes. In: Atmospheric chemistry and physics Bd. 19. Katlenburg-Lindau, EGU (2019), Nr. 3, S. 1703–1719
• Bubenzer, Olaf ; Gebhardt, Hans ; Keppler, Frank: Der Mensch als geologische Kraft: Das Zeitalter des Anthropozäns. In: Pfeiffer, T. (Hrsg.) Ruperto Carola Bd. 15. Heidelberg ; Heidelberg ; Heidelberg ; Heidelberg ; Heidelberg, Universität Heidelberg, Der Rektor, Kommunikation und Marketing ; Vereinigung der Freunde der Studentenschaft der Univ. Heidelberg ; Brausdr. ; Univ., Presse- und Informationsstelle ; Winter (2019), S. 24–33
• Boros, Mihály ; Keppler, Frank: Methane production and bioactivity: a link to oxido-reductive stress. In: Frontiers in physiology Bd. 10. Lausanne, Frontiers Research Foundation (2019)

2018

• Polag, Daniela ; Keppler, Frank: Long-term monitoring of breath methane. In: The science of the total environment Bd. 624. Amsterdam [u.a.], Elsevier Science (2018), S. 69–77
• Schulze-Makuch, Dirk ; Wagner, Dirk ; Kounaves, Samuel P. ; Mangelsdorf, Kai ; Devine, Kevin G. ; Vera, Jean-Pierre de ; Schmitt-Kopplin, Philippe ; Grossart, Hans-Peter ; Parro, Victor ; u. a.: Transitory microbial habitat in the hyperarid Atacama desert. In: Proceedings of the National Academy of Sciences of the United States of America Bd. 115. Washington, DC, National Acad. of Sciences (2018), Nr. 11, S. 2670–2675
• Anhäuser, Tobias ; Greule, Markus ; Keppler, Frank: Earliest Eocene cold period and polar amplification: insights from [delta]2H values of lignin methoxyl groups of mummified wood. In: Palaeogeography, palaeoclimatology, palaeoecology Bd. 505. Amsterdam [u.a.], Elsevier Science (2018), S. 326–336
• Jäger, Nicole ; Röhling, Amelie Ninja ; Koch, Fabien ; Greule, Markus ; Keppler, Frank: Chloromethane formation and degradation in the fern phyllosphere. In: The science of the total environment Bd. 634. Amsterdam [u.a.], Elsevier Science (2018), S. 1278–1287
• Kleint, Jan F. ; Schiller, Amanda ; Greule, Markus ; Keppler, Frank ; Isenbeck-Schröter, Margot: A fast and sensitive method for the continuous in situ determination of dissolved methane and its [delta]13C-isotope ratio in surface waters. In: Limnology and oceanography Bd. 16. Oxford [u.a.] ; Waco, Tex., Wiley-Blackwell ; ASLO (2018), Nr. 5, S. 273–285
• Keppler, Frank ; Greule, Markus ; Schöler, Heinz Friedrich: Mass spectrometric measurement of hydrogen isotope fractionation for the reactions of chloromethane with OH and Cl. In: Atmospheric chemistry and physics Bd. 18. Katlenburg-Lindau, EGU (2018), Nr. 9, S. 6625–6635
• May, Tobias ; Polag, Daniela ; Keppler, Frank ; Greule, Markus: Methane oxidation in industrial biogas plants: insights in a novel methanotrophic environment evidenced by pmoA gene analyses and stable isotope labelling studies. In: Journal of biotechnology Bd. 270. Amsterdam [u.a.], Elsevier Science (2018), S. 77–84
• Jäger, Nicole ; Greule, Markus ; Keppler, Frank: Chloromethane degradation in soils: a combined microbial and two-dimensional stable isotope approach. In: Journal of environmental quality Bd. 47. Hoboken, NJ ; Madison, Wis, Wiley ; ASA, CSSA, and SSSA (2018), Nr. 2, S. 254–262
• Esper, Jan ; Holzkämper, Steffen ; Keppler, Frank: Site-specific climatic signals in stable isotope records from Swedish pine forests. In: Trees Bd. 32. Berlin ; Heidelberg ; New York, Springer (2018), Nr. 3, S. 855–869
• Comba, Peter ; Faltermeier, Dieter ; Keppler, Frank ; Schöler, Heinz Friedrich ; Schroll, Moritz: Iron catalyzed demethylation of acetic acid. In: Journal of coordination chemistry Bd. 71. London [u.a.] ; New York, NY [u.a.], Taylor & Francis ; Gordon & Breach (2018), Nr. 11/3, S. 1704–1714

2017

• Anhäuser, Tobias ; Greule, Markus ; Keppler, Frank: Stable hydrogen isotope values of lignin methoxyl groups of four tree species across Germany and their implication for temperature reconstruction. In: The science of the total environment Bd. 579. Amsterdam [u.a.], Elsevier Science (2017), S. 263–271
• Anhäuser, Tobias ; Greule, Markus ; Polag, Daniela ; Bowen, Gabriel J. ; Keppler, Frank: Mean annual temperatures of mid-latitude regions derived from [delta]2H values of wood lignin methoxyl groups and its implications for paleoclimate studies. In: The science of the total environment Bd. 574. Amsterdam [u.a.], Elsevier Science (2017), S. 1276–1282
• Mulat, Daniel Girma ; Polag, Daniela ; Greule, Markus ; Keppler, Frank: Exogenous addition of H2 for an in situ biogas upgrading through biological reduction of carbon dioxide into methane. In: Waste management Bd. 68. Amsterdam [u.a.], Elsevier Science (2017), S. 146–156
• Riechelmann, Dana ; Greule, Markus ; Anhäuser, Tobias ; Keppler, Frank: Warm season precipitation signal in [delta]2H values of wood lignin methoxyl groups from high elevation larch trees in Switzerland. In: Rapid communications in mass spectrometry Bd. 31. New York, NY, Wiley Interscience (2017), Nr. 19, S. 1589–1598
• Benzing, Kathrin Julia ; Comba, Peter ; Martin, Bodo ; Pokrandt, Bianca ; Keppler, Frank: Nonheme iron-oxo-catalyzed methane formation from methyl thioethers: scope, mechanism, and relevance for natural systems. In: Chemistry - a European journal Bd. 23. Weinheim, Wiley-VCH (2017), Nr. 43, S. 10465–10472
• Schreiber, Ulrich C. ; Greule, Markus ; Keppler, Frank ; Mulder, Ines ; Sattler, Tobias ; Schöler, Heinz Friedrich: Organic compounds in fluid inclusions of Archean quartz: analogues of prebiotic chemistry on early earth. In: PLOS ONE Bd. 12. San Francisco, California, US ; Lawrence, Kan., PLOS ; PLoS (2017), Nr. 6
• Keppler, Frank ; Fischer, Jan ; Sattler, Tobias ; Polag, Daniela ; Jäger, Nicole ; Schöler, Heinz Friedrich ; Greule, Markus: Chloromethane emissions in human breath. In: The science of the total environment Bd. 605/606. Amsterdam [u.a.], Elsevier Science (2017), S. 405–410
• Geißler, Katrin ; Greule, Markus ; Keppler, Frank: Vanilla authenticity control by DNA barcoding and isotope data aggregation. In: Flavour and fragrance journal Bd. 32. New York, NY [u.a.], Wiley (2017), Nr. 4, S. 228–237
• Hepp, Johannes ; Greule, Markus ; Keppler, Frank: Late Quaternary relative humidity changes from Mt. Kilimanjaro, based on a coupled 2H-18O biomarker paleohygrometer approach. In: Quaternary international Bd. 438. Amsterdam [u.a.], Elsevier Science (2017), S. 116–130

2016

• Keppler, Frank ; Schiller, Amanda ; Greule, Markus ; Kleint, Jan F. ; Polag, Daniela: Stable isotope and high precision concentration measurements confirm that all humans produce and exhale methane. In: Journal of breath research Bd. 10. Bristol, IOP (2016), Nr. 1
• Riechelmann, Dana ; Greule, Markus ; Keppler, Frank: Climate signals in [delta]13C of wood lignin methoxyl groups from high-elevation larch trees. In: Palaeogeography, palaeoclimatology, palaeoecology Bd. 445. Amsterdam [u.a.], Elsevier Science (2016), S. 60–71
• Lenhart, Katharina ; Klintzsch, Thomas ; Langer, Gerald ; Nehrke, Gernot ; Bunge, Michael ; Schnell, Sylvia ; Keppler, Frank: Evidence for methane production by the marine algae Emiliania huxleyi. In: Biogeosciences Bd. 13. Katlenburg-Lindau [u.a.], Copernicus (2016), Nr. 10, S. 3163–3174

2015

• Stable hydrogen and carbon isotope ratios of methoxyl groups during plant litter degradation. In: Isotopes in environmental and health studies Bd. 51. London [u.a.], Taylor and Francis (2015), Nr. 1, S. 143–154
• Technical note: Methionine, a precursor of methane in living plants. In: Biogeosciences Bd. 12. Katlenburg-Lindau [u.a.], Copernicus (2015), Nr. 6, S. 1907–1914
• Comment on authenticity and traceability of vanilla flavors by analysis of stable isotopes of carbon and hydrogen. In: Journal of agricultural and food chemistry Bd. 63. Washington, DC [u.a.], ACS Publications (2015), Nr. 21, S. 5305–5306
• Design and application of a synthetic DNA standard for real-time PCR analysis of microbial communities in a biogas digester. In: Applied microbiology and biotechnology Bd. 99. Berlin ; Heidelberg ; New York, Springer (2015), S. 6721–6729
• Nitrous oxide and methane emissions from cryptogamic covers. In: Global change biology Bd. 21. Oxford [u.a.] ; Oxford ; Oxford [u.a.], Wiley-Blackwell ; Blackwell Science ; Blackwell (2015), Nr. 8, S. ?
• Seasonal changes in chlorine and methoxyl content of leaves of deciduous trees and their impact on release of chloromethane and methanol at elevated temperatures. In: Environmental chemistry Bd. 12. Collingwood, Vic., CSIRO Publ. (2015), Nr. 4, S. 426–437
• Polag, Daniela ; Keppler, Frank: Online monitoring of stable carbon isotopes of methane in anaerobic digestion as a new tool for early warning of process instability. In: Bioresource technology Bd. 197. Amsterdam [u.a.], Elsevier Science (2015), S. 161–170
• Mischel, Maria ; Esper, Jan ; Keppler, Frank ; Greule, Markus: [Delta]2H, [delta]13C and [delta]18O from whole wood, α-cellulose and lignin methoxyl groups in Pinus sylvestris: a multi-parameter approach. In: Isotopes in environmental and health studies Bd. 51. London [u.a.], Taylor and Francis (2015), Nr. 4, S. 553–568
• A stable isotope approach to assessing water loss in fruits and vegetables during storage. In: Journal of agricultural and food chemistry Bd. 63. Washington, DC [u.a.], ACS Publications (2015), Nr. 7, S. 1974–1981
• Keppler, Frank: Leben wir in einem neuen Zeitalter? Heidelberg : Universitätsbibliothek Heidelberg, 2015

2014

• Stable bromine isotopic composition of methyl bromide released from plant matter. In: Geochimica et cosmochimica acta Bd. 125. New York, NY [u.a.], Elsevier (2014), S. 153–160
• Stable carbon isotopes of methane for real-time process monitoring in anaerobic digesters. In: Engineering in life sciences Bd. 14. Weinheim, Wiley-VCH (2014), Nr. 2, S. 153–160
• Polag, Daniela ; Leiß, Ottmar ; Keppler, Frank: Age dependent breath methane in the German population. In: The science of the total environment Bd. 481. Amsterdam [u.a.], Elsevier Science (2014), S. 582–587
• Abiotic methanogenesis from organosulphur compounds under ambient conditions. In: Nature Communications Bd. 5. [London] ; [London], Springer Nature ; Nature Publishing Group UK (2014)
• D/H ratios of methoxyl groups of the sedimentary organic matter of Lake Holzmaar (Eifel, Germany): a potential palaeoclimate/-hydrology proxy. In: Geochimica et cosmochimica acta Bd. 142. New York, NY [u.a.], Elsevier (2014), S. 39–52
• Probing the diversity of chloromethane-degrading bacteria by comparative genomics and isotopic fractionation. In: Frontiers in microbiology Bd. 5. Lausanne, Frontiers Media (2014)
• Chloromethane release from carbonaceous meteorite affords new insight into Mars lander findings. In: Scientific reports Bd. 4. [London] ; London, Springer Nature ; Nature Publishing Group (2014), S. ?

2013

• Carbon, hydrogen and oxygen stable isotope ratios of whole wood, cellulose and lignin methoxyl groups of Picea abies as climate proxies. In: Rapid communications in mass spectrometry Bd. 27. New York, NY, Wiley Interscience (2013), Nr. 1, S. 265–275
• Position-specific isotope analysis of the methyl group carbon in methylcobalamin for the investigation of biomethylation processes. In: Analytical and bioanalytical chemistry Bd. 405. Berlin ; Heidelberg, Springer (2013), Nr. 9, S. 2833–2841
• Evidence of anaerobic syntrophic acetate oxidation in biogas batch reactors by analysis of 13C carbon isotopes. In: Isotopes in environmental and health studies Bd. 49. London [u.a.], Taylor and Francis (2013), Nr. 3, S. 365–377
• Hydrogen and carbon isotope fractionation during degradation of chloromethane by methylotrophic bacteria. In: MicrobiologyOpen Bd. 2. Malden, Mass., Wiley (2013), Nr. 6, S. 893–900

2012

• Methyl chloride emissions from halophyte leaf litter: dependence on temperature and chloride content. In: Chemosphere Bd. 87. Amsterdam [u.a.], Elsevier Science (2012), Nr. 5, S. 483–489
• Release of methane from aerobic soil: An indication of a novel chemical natural process? In: Chemosphere Bd. 86. Amsterdam [u.a.], Elsevier Science (2012), Nr. 6, S. 684–689
• Ultraviolet-radiation-induced methane emissions from meteorites and the Martian atmosphere. Bd. 486. London [u.a.] ; London : Nature Publ. Group ; Macmillan, 2012
• Evidence for methane production by saprotrophic fungi. In: Nature Communications Bd. 3. [London] ; [London], Springer Nature ; Nature Publishing Group UK (2012), S. 1–8
• Greule, Markus ; Huber, Stefan ; Keppler, Frank: Stable hydrogen-isotope analysis of methyl chloride emitted from heated halophytic plants. In: Atmospheric environment Bd. 62. Amsterdam [u.a.], Elsevier Science (2012), S. 584–592

2011

• Enhanced formation of methane in plant cell cultures by inhibition of cytochrome c oxidase. In: Plant, cell & environment Bd. 34. Oxford [u.a.] ; Oxford ; Oxford [u.a.], Wiley-Blackwell ; Blackwell Science ; Blackwell (2011), Nr. 3, S. 457–464
• Methyl chloride and C2-C5 hydrocarbon emissions from dry leaf litter and their dependence on temperature. In: Atmospheric environment Bd. 45. Amsterdam [u.a.], Elsevier Science (2011), Nr. 18, S. 3112–3119
• Non-microbial methane emissions from fresh leaves: effects of physical wounding and anoxia. In: Atmospheric environment Bd. 45. Amsterdam [u.a.], Elsevier Science (2011), Nr. 28, S. 4915–4921
• Greule, Markus ; Keppler, Frank: Stable isotope determination of ester and ether methyl moieties in plant methoxyl groups. In: Isotopes in environmental and health studies Bd. 47. London [u.a.], Taylor and Francis (2011), Nr. 4, S. 470–482

2010

• Identification of methanogenic pathways in anaerobic digesters using stable carbon isotopes. In: Engineering in life sciences Bd. 10. Weinheim, Wiley-VCH (2010), Nr. 6, S. 509–514
• Improved rapid authentication of vanillin using [delta]13C and [delta]2H values. In: European food research and technology Bd. 231. Berlin ; Heidelberg [u.a.], Springer (2010), Nr. 6, S. 933–941
• Isotopic composition of H2 from wood burning: dependency on combustion efficiency, moisture content, and [delta]D of local precipitation. In: Journal of geophysical research Bd. 115. Hoboken, NJ ; Hoboken, NJ, Wiley ; AGU Publications (2010), Nr. D17
• Measurements of 13C/12C methane from anaerobic digesters: comparison of optical spectrometry with continuous-flow isotope ratio mass spectrometry. In: Environmental science & technology Bd. 44. Columbus, Ohio, American Chemical Society (2010), Nr. 13, S. 5067–5073
• Althoff, Frederik ; Jugold, Alke ; Keppler, Frank: Methane formation by oxidation of ascorbic acid using iron minerals and hydrogen peroxide. In: Chemosphere Bd. 80. Amsterdam [u.a.], Elsevier Science (2010), S. 286–292
• Water drives the deuterium content of the methane emitted from plants. In: Geochimica et cosmochimica acta Bd. 74. New York, NY [u.a.], Elsevier (2010), Nr. 14, S. 3865–3873

2009

• Methane formation in aerobic environments. In: Environmental chemistry Bd. 6. Collingwood, Vic., CSIRO Publ. (2009), Nr. 6, S. 459–465
• Fast determination of methyl chloride and methyl bromide emissions from dried plant matter and soil samples using HS-SPME and GC-MS: method and first results. In: Environmental chemistry Bd. 6. Collingwood, Vic., CSIRO Publ. (2009), Nr. 4, S. 311–318
• A simple rapid method to precisely determine 13C/12C ratios of plant methoxyl groups. In: Rapid communications in mass spectrometry Bd. 23. New York, NY, Wiley Interscience (2009), Nr. 11, S. 1710–1714
• The stable isotope signature of methane emitted from plant material under UV irradiation. In: Atmospheric environment Bd. 43. Amsterdam [u.a.], Elsevier Science (2009), Nr. 35, S. 5637–5646
• Late Permian changes in conditions of the atmosphere and environments caused by halogenated gases. In: Doklady earth sciences Bd. 425. Moscow ; Berlin ; Heidelberg [u.a.], MAIK Nauka/Interperiodica Publ. ; Springer Science+Business Media (2009), Nr. 2, S. 291–295

2008

• Keppler, Frank ; Hamilton, John T. G.: Tracing the geographical origin of early potato tubers using stable hydrogen isotope ratios of methoxyl groups. In: Isotopes in environmental and health studies Bd. 44. London [u.a.], Taylor and Francis (2008), Nr. 4, S. 337–347
• A rapid and precise method for determination of D/H ratios of plant methoxyl groups. In: Rapid communications in mass spectrometry Bd. 22. New York, NY, Wiley Interscience (2008), Nr. 24, S. 3983–3988
• Abiotic methyl bromide formation from vegetation, and iIts strong dependence on temperature. In: Environmental science & technology Bd. 42. Columbus, Ohio, American Chemical Society (2008), Nr. 18, S. 6837–6842
• Effect of UV radiation and temperature on the emission of methane from plant biomass and structural components. In: Biogeosciences Bd. 5. Katlenburg-Lindau [u.a.], Copernicus (2008), S. 937–947
• Methoxyl groups of plant pectin as a precursor of atmospheric methane: evidence from deuterium labelling studies. In: The new phytologist Bd. 178. Oxford [u.a.] ; Oxford ; Oxford [u.a.], Wiley-Blackwell ; Blackwell Science ; Blackwell (2008), Nr. 4, S. 808–814
• Draxler, Susanne ; Keppler, Frank: Ansätze zur regionalen Quantifizierung von Methan aus Pflanzen. In: Umweltwissenschaften und Schadstoff-Forschung Bd. 20. Heidelberg ; Landsberg, Springer ; ecomed-Verlagsges. (2008), Nr. 1, S. 75–79

2007

• Stable hydrogen isotope ratios of lignin methoxyl groups as a paleoclimate proxy and constraint of the geographical origin of wood. In: The new phytologist Bd. 176. Oxford [u.a.] ; Oxford ; Oxford [u.a.], Wiley-Blackwell ; Blackwell Science ; Blackwell (2007), Nr. 3, S. 600–609
• Rösing, Gerhard ; Keppler, Frank: Verfahren zur Herstellung von Biogas:  = Method for producing biogas. Geneva : WIPO, 2007

2006

• De novo formation of chloroethyne in soil. In: Environmental science & technology Bd. 40. Columbus, Ohio, American Chemical Society (2006), Nr. 1, S. 130–134
• Methane emissions from terrestrial plants under aerobic conditions. Bd. 439. London [u.a.] ; London : Nature Publ. Group ; Macmillan, 2006
• Atmospheric constraints on global emissions of methane from plants. In: Geophysical research letters Bd. 33. Hoboken, NJ ; Washington, DC, Wiley ; American Geophysical Union (2006), Nr. 15

2005

• Schöler, Heinz Friedrich ; Keppler, Frank: Abiotic formation of organohalogens in the terrestrial environment. In: Zellner, R. (Hrsg.): Volatile chlorinated hydrocarbons. Frankfurt am Main : GDCh, 2005 — ISBN 3936028346, S. 14–23
• New insight into the atmospheric chloromethane budget gained using stable carbon isotope ratios. In: Atmospheric chemistry and physics Bd. 5. Katlenburg-Lindau, EGU (2005), Nr. 9, S. 2403–2411

2004

• Carbon isotope anomaly in the major plant C1 pool and its global biogeochemical implications. In: Biogeosciences Bd. 1. Katlenburg-Lindau [u.a.], Copernicus (2004), Nr. 2, S. 123–131
• Halogen retention, organohalogens and the role of organic matter decomposition on halogen enrichment in two Chilean peat bogs. In: Environmental science & technology Bd. 38. Columbus, Ohio, American Chemical Society (2004), Nr. 7, S. 1984–1991

2003

• Schöler, Heinz Friedrich ; Keppler, Frank: Abiotic formation of organohalogens during early diagenetic processes. In: Gribble, G. W. (Hrsg.): Natural production of organohalogen compounds. Berlin ; Heidelberg [u.a.] : Springer, 2003 — ISBN 9783540452935, S. 63–84
• Organoiodine formation during humification in peatlands. In: Environmental chemistry letters Bd. 1. Berlin [u.a.], Springer (2003), Nr. 4, S. 219–223
• Chloride methylation by plant pectin: an efficient environmentally eignificant process. In: Science Bd. 301. Washington, DC, American Association for the Advancement of Science (2003), S. 206–209
• Keppler, Frank ; Biester, Harald: Peatlands: a major sink of naturally formed organic chlorine. In: Chemosphere Bd. 52. Amsterdam [u.a.], Elsevier Science (2003), Nr. 2, S. 451–453
• Fluxes of trichloroacetic acid between atmosphere, biota, soil, and groundwater. In: Chemosphere Bd. 52. Amsterdam [u.a.], Elsevier Science (2003), Nr. 2, S. 339–354
• Fahimi, Isabelle Jasmine ; Keppler, Frank ; Schöler, Heinz Friedrich: Formation of chloroacetic acids from soil, humic acid and phenolic moieties. In: Chemosphere Bd. 52. Amsterdam [u.a.], Elsevier Science (2003), Nr. 2, S. 513–520
• Formation of volatile iodinated alkanes in soil: results from laboratory studies. In: Chemosphere Bd. 52. Amsterdam [u.a.], Elsevier Science (2003), Nr. 2, S. 477–483
• Putschew, Anke ; Keppler, Frank ; Jekel, Martin: Differentiation of the halogen content of peat samples using ion chromatography after combustion (TX/TOX-IC). In: Analytical and bioanalytical chemistry Bd. 375. Berlin ; Heidelberg, Springer (2003), Nr. 6, S. 781–785
• De novo formation of organochlorines in a sewage treatment plant. In: Biogeochemistry Bd. 62. Cham ; Dordrecht ; Boston ; Dordrecht ; Dordrecht, Springer ; Nijhoff/Junk ; Kluwer ; Springer Science + Business Media B.V. (2003), Nr. 3, S. 277–287

2002

• Natural formation of vinyl chloride in the terrestrial environment. In: Environmental science & technology Bd. 36. Columbus, Ohio, American Chemical Society (2002), S. 2479–2483
• Keppler, Frank ; Schöler, Heinz Friedrich: Natürliche Ozonkiller aus dem Boden. In: Pfeiffer, T. (Hrsg.) Ruperto Carola. Heidelberg ; Heidelberg ; Heidelberg ; Heidelberg ; Heidelberg, Universität Heidelberg, Der Rektor, Kommunikation und Marketing ; Vereinigung der Freunde der Studentenschaft der Univ. Heidelberg ; Brausdr. ; Univ., Presse- und Informationsstelle ; Winter (2002), Nr. 2, S. 20–24
• Keppler, Frank ; Schöler, Heinz Friedrich: Report on the Second International Conference on ‘Naturally Produced Organohalogens’. In: Environmental science and pollution research Bd. 9. Berlin ; Heidelberg ; Landsberg, Springer ; ecomed-Verlagsges. (2002), Nr. 2, S. 154

2001

• Abiotic Fe(III) induced mineralization of phenolic substances. In: Chemosphere Bd. 44. Amsterdam [u.a.], Elsevier Science (2001), Nr. 4, S. 613–619

2000

• Halocarbons produced by natural oxidation processes during degradation of organic matter. Bd. 403. London [u.a.] ; London : Nature Publ. Group ; Macmillan, 2000
• Keppler, Frank: Abiotische Bildung leichtflüchtiger Organohalogenverbindungen im Boden, 2000. — Heidelberg, Univ., Diss., 2000

1998

• Bildung von Organohalogenen in einer kommunalen Kläranlage. In: Vom Wasser Bd. 91. Weinheim ; Berlin ; Weinheim, Bergstr. ; Weinheim, Wiley-VCH ; Verlag Chemie ; Verl. Chemie ; VCH Verl.-Ges. (1998), S. 175–184