A5080747631- Isotope Analysis in Ecology
- Groundwater and Isotope Geochemistry
- Radioactive contamination and transfer
- Geology and Paleoclimatology Research
- Toxic Organic Pollutants Impact
- Methane Hydrates and Related Phenomena
- Analytical chemistry methods development
- Soil Carbon and Nitrogen Dynamics
- Microbial bioremediation and biosurfactants
- Radioactive element chemistry and processing
- Microbial Community Ecology and Physiology
- Mass Spectrometry Techniques and Applications
- Marine and coastal ecosystems
- Peatlands and Wetlands Ecology
- Nuclear Physics and Applications
- Protist diversity and phylogeny
- Pesticide and Herbicide Environmental Studies
- Soil and Water Nutrient Dynamics
- Pharmaceutical and Antibiotic Environmental Impacts
- Wastewater Treatment and Nitrogen Removal
- Metabolomics and Mass Spectrometry Studies
- Water Treatment and Disinfection
- Atmospheric chemistry and aerosols
- Geochemistry and Elemental Analysis
- Chemical Analysis and Environmental Impact
Helmholtz Centre for Environmental Research
2016-2025
University of Groningen
2015
RWTH Aachen University
2010
Helmholtz Association of German Research Centres
2008
Deutsches Biomasseforschungszentrum
1994-2006
University of Bayreuth
2006
United States Geological Survey
2006
Max Planck Institute for Biogeochemistry
2006
International Atomic Energy Agency
2006
Consistency of delta13C measurements can be improved 39-47% by anchoring the scale with two isotopic reference materials differing substantially in 13C/12C. It is recommended that values both organic and inorganic measured expressed relative to VPDB (Vienna Peedee belemnite) on a normalized assigning consensus -46.6 per thousand L-SVEC lithium carbonate +1.95 NBS 19 calcium carbonate. Uncertainties other material this are factors up or more, some have been notably shifted: 22 oil -30.03 thousand.
Abstract A method for isotope ratio analysis of water samples is described comprising an on‐line high‐temperature reduction technique in a helium carrier gas. Using gas‐tight syringe, injection 0.5 to 1 μL sample made through heated septum into glassy carbon reactor at temperatures excess 1300°C. More than 150 injections can be per day and both ratios interest, δ 2 H 18 O, measured with the same setup. The has capability transfer high‐precision stable from specialized routine laboratory task...
A method for the automated sample conversion and on-line oxygen isotope ratio (delta(18)O) determination organic inorganic substances is presented. The samples are pyrolytically decomposed at 1400 degrees C in presence of nickelized graphite. With system presented as well such nitrates, sulphates phosphates 50-100 &mgr;g O can be analyzed their delta(18)O values with a standard deviation usually better than 0.5 per thousand. Additionally, carbon ratios nitrogen nitrogenous compounds...
A new technique for the sample preparation, directly coupled to an isotope ratio mass spectrometer (IRMS) D/H determination, is described. The method suitable preparation of fresh and saline waters as well different organic compounds (gaseous or liquid). One microliter water hydrogen equivalent injected reduced by means chromium metal in a specially designed reaction furnace, then gas flows into IRMS be analyzed standard/sample comparison. reproducibility about 1‰. accuracy this confirmed...
Abstract Internationally distributed organic and inorganic oxygen isotopic reference materials have been calibrated by six laboratories carrying out more than 5300 measurements using a variety of high‐temperature conversion techniques (HTC) in an evaluation sponsored the International Union Pure Applied Chemistry (IUPAC). To aid calibration these materials, which span 125‰, artificially enriched water ( δ 18 O +78.91‰) two barium sulfates (one depleted one O) were prepared relative to VSMOW2...
An international project developed, quality-tested, and determined isotope−δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), IAEA-600 (caffeine). These enable users normalize measurements samples scales. The span a range δ2HVSMOW-SLAP from −210.8 +397.0 mUr or ‰, δ13CVPDB-LSVEC −40.81 +0.49 δ15NAir −5.21 +61.53 mUr. Many the are amenable...
During organic contaminant degradation in soil, bound or nonextractable residues (NER) are formed. Part of these may be biogenic, because degrading microorganisms assimilate carbon derived from the pollutant and mineralized CO(2) to form cellular components for example, [fatty acids (FA) amino (AA)], which subsequently stabilized within soil matter (SOM). We investigated formation fate FA AA biodegradation (13)C(6)-2,4-D incorporation (13)C-label into living biomass via (13)CO(2) fixation....
In recent years the analysis of stable isotope fractionation has increasingly been used for characterizing and quantifying biodegradation contaminants in aquifers. The correlation carbon hydrogen signatures benzene a BTEX-contaminated aquifer located area former hydrogenation plant gave indications that mainly occurred under anoxic conditions. This finding was consistent with investigation hydrogeochemical conditions within aquifer. Furthermore, calculated by changes using...
The high temperature conversion (HTC) technique using an elemental analyzer with a glassy carbon tube and filling (temperature conversion/elemental analysis, TC/EA) is widely used method for hydrogen isotopic analysis of water many solid liquid organic samples by isotope-ratio mass spectrometry (IRMS). However, the TC/EA IRMS may produce inaccurate δ(2)H results, values deviating more than 20 mUr (milliurey = 0.001 1‰) from true value some materials. We show that single-oven, chromium-filled...
The traditional high-temperature conversion (HTC) approach toward compound-specific stable isotope analysis (CSIA) of hydrogen for heteroatom-bearing (i.e., N, Cl, S) compounds has been afflicted by fractionation bias due to formation byproducts HCN, HCl, and H2S. This study presents a chromium-based (Cr/HTC) organic containing nitrogen, chlorine, sulfur. Following peak separation along gas chromatographic (GC) column, the use thermally ceramic Cr/HTC reactors at 1100-1500 °C chemical...
A universal method for pyrolysis and elemental analysis, suitable the online determination of deuterium, carbon, nitrogen oxygen isotopes organic inorganic substances, is presented. The samples are pyrolytically decomposed in a high-temperature (HTP) system, at temperature exceeding 1400 degrees C, presence reactive carbon. analysis stable isotope ratios from hydrogen, oxygen. instrumentation experimental procedure simple cost-effective. reproducibility delta values D/H better than 3 per...
In the present study, coupled stable sulfur and oxygen isotope fractionation during elemental disproportionation according to overall reaction: 4H2O + 4Sˆ → 3H2S SO4 2 − 2H+, was experimentally investigated for first time using a pure culture of sulfate reducer Desulfobulbus propionicus at 35ˆC. Bacterial is an important process in cycle natural surface sediments leads simultaneous formation sulfide sulfate. A dual-isotope approach considering both discrimination has been shown be most...
Reliable compound-specific isotope enrichment factors are needed for a quantitative assessment of in situ biodegradation contaminated groundwater. To obtain information on the variability carbon and hydrogen (εC, εH) fractionation methyl tertiary (tert-) butyl ether (MTBE) ethyl tert-butyl (ETBE) upon aerobic degradation was studied with different bacterial isolates. Methylibium sp. R8 showed MTBE −2.4 ± 0.1 −42 4‰, respectively, which is range previous studies pure cultures (Methylibium...
Using bulk tissue and fatty acid 13 C analysis we investigated major trophic pathways from soil microorganisms to microbial consumers predators in conventional versus organic farming systems planted for the first time with maize. Organic led an increase biomass particular that of fungi as indicated by phospholipid acids (PLFAs). Microbial PLFAs reflected conversion 3 4 plants a shift δ 2‰, whereas isotopic signal (FAs) Collembola was much more pronounced. In euedaphic Protaphorura fimata...
α-Hexachlorocyclohexane (α-HCH) is the only chiral isomer of eight 1,2,3,4,5,6-HCHs and we have developed an enantiomer-specific stable carbon isotope analysis (ESIA) method for evaluation its fate in environment. The ratios α-HCH enantiomers were determined a commercially available sample using gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) system equipped with column. GC-C-IRMS measurements revealed δ-values -32.5 ± 0.8‰ -32.3 0.5‰ (-) (+) α-HCH, respectively....
Stable chlorine isotope analysis is increasingly used to characterize sources, transformation pathways, and sinks of organic aliphatic compounds, many them being priority pollutants in groundwater the atmosphere. A wider use isotopes environmental studies still inhibited by limitations different analytical techniques such as high sample needs, offline preparation, confinement few compounds mediocre precision, respectively. Here we present a method for δ37Cl determination volatile using gas...
Abstract. In natural coastal wetlands, high supplies of marine sulfate suppress methanogenesis. Coastal wetlands are, however, often subject to disturbance by diking and drainage for agricultural use can turn potent methane sources when rewetted remediation. This suggests that preceding land measures suspend the sulfate-related suppressing mechanisms. Here, we unravel hydrological relocation biogeochemical S C transformation processes induced emissions in a disturbed peatland despite former...
The present study aims to understand the impact of submarine groundwater discharge (SGD) on a coastal area with different lithology and degrees SGD. Sampling campaigns took place in Puck Bay Gulf Gdańsk, southern Baltic Sea encompassing years between 2009 2021. methodological approach combined geophysical characterization surface sediments detailed spatial temporal (isotope) biogeochemical investigations pore waters, was supported by nearshore river surveys. Acoustic identified areas...
Multi-element compound-specific stable isotope analysis (ME-CSIA) allows monitoring the environmental behavior and transformation of most common persistent contaminants. Recent advancements in analytical techniques have extended applicability ME-CSIA to organic micropollutants, including pesticides. Nevertheless, application this methodology remains unexplored concerning harmful insecticides such as methoxychlor, a polar organochlorine pesticide usually detected soil groundwater. This study...
Abstract The microbial carbon and hydrogen isotope fractionation of benzene under sulfate‐reducing conditions was investigated within systems increasing complexity: (i) batch laboratory microcosms, (ii) a groundwater‐percolated column system, (iii) an aquifer transect. Recent molecular biological studies indicate that, at least in the microcosms is degraded by similar bacterial communities. Carbon enrichment factors ( ε C , H ) obtained from study varied significantly although experiments...
The anaerobic oxidation of methane (AOM) is an important sink in marine ecosystems mediated by still uncultured Archaea. We established experimental system to grow AOM communities different sediment samples. Approaches show growth the slow-growing methanotrophs have been either via nucleic acids (quantitative PCR) or required long-term incubations. Previous experiments with (13)C-labelled led unspecific distribution (13)C-label. Although quantitative PCR a sensitive technique detect small...