Timothy I Eglinton
Dados Biográficos
| ID | 4129769 |
|---|---|
| NOME | Timothy I Eglinton |
| PRENOMES | Timothy I |
| SOBRENOME | Eglinton |
| ASSINATURA | EGLINTON T I |
| AFILIAÇÕES | ETH Zurich |
| ORCID | 0000-0001-5060-2155 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 25 |
| TOTAL DE CITAÇÕES | 61 |
| TOTAL COMO AUTOR | 25 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 2003 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2025 |
| ÍNDICE H | 4 |
Pollen 14 C dating compared with established dating methods
Radiocarbon ( 14 C) dating is a powerful tool for establishing reliable chronologies for proxy records recovered from environmental archives, including lacustrine sediments. However, lacustrine sediments are often limited with respect to availability of material such as terrestrial macrofossils that are traditionally targeted for 14 C dating. Flow cytometry, in combination with physicochemical preprocessing, is an emerging technique for the isola…
Towards online ramped oxidation (ORO)-AMS for thermal dissection and serial radiocarbon analysis of complex organic matter
By constraining organic carbon (OC) turnover times and ages, radiocarbon ( 14 C) analysis has become a crucial tool to study the global carbon cycle. However, commonly used “bulk” measurements yield average turnover times, masking age variability within complex OC mixtures. One method to unravel intra-sample age distributions is ramped oxidation, in which OC is oxidized with the aid of oxygen at increasing temperatures. The resulting CO 2 is coll…
Mineralogy as a potential driver of irregular radiocarbon patterns among Icelandic fluvial carbon pools
Fluvial export of organic carbon (OC) from the terrestrial biosphere to the ocean forms a key component of the global carbon cycle. Carbon sources and transformations along the land–ocean aquatic continuum are dynamic with a complex interplay between particulate and dissolved organic and inorganic carbon pools (POC, DOC, DIC). Radiocarbon dating serves as a valuable tool, providing crucial insights into turnover and residence times within these p…
A Universal Gas Interface for Simultaneous 14 C and Δ 13 C Measurements
While simultaneous radiocarbon and δ 13 C measurements have been available for organic materials (by accelerator mass spectrometry, AMS, and isotope ratio mass spectrometry, IRMS, respectively), this has not been possible for carbonates until now. Using an existing interface for gas ion source AMS measurements, we developed a prototype for a universal gas interface that allows simultaneous measurement of both carbon isotope ratios from potentiall…
Seasonal variability in particulate organic carbon degradation in the Kolyma River, Siberia
Major Arctic rivers are undergoing changes due to climate warming with higher discharge and increased amounts of solutes and organic carbon (OC) draining into rivers and coastal seas. Permafrost thaw mobilizes previously frozen OC to the fluvial network where it can be degraded into greenhouse gases and emitted to the atmosphere. Degradation of OC during downstream transport, especially of the particulate OC (POC), is however poorly characterized…
Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies
Enhanced warming of the Northern high latitudes has intensified thermokarst processes throughout the permafrost zone. Retrogressive thaw slumps (RTS), where thaw-driven erosion caused by ground ice melt creates terrain disturbances extending over tens of hectares, represent particularly dynamic thermokarst features. Biogeochemical transformation of the mobilized substrate may release CO 2 to the atmosphere and impact downstream ecosystems, yet it…
Source forensics of n-alkanes and n-fatty acids in urban aerosols using compound specific radiocarbon/stable carbon isotopic composition
n -Alkanes and fatty acids are important molecular markers for the source apportionment of organic matter in the atmosphere. Traditional approaches to date have mostly relied upon the source-specific differences in their molecular distributions and carbon preference index. Alternatively, we demonstrate here the use of stable carbon and radiocarbon isotopic composition ( δ 13 C and Δ 14 C, respectively) of n -alkanes and n -fatty acids in aerosols…
C Blank Assessment in Small-Scale Compound-Specific Radiocarbon Analysis of Lipid Biomarkers and Lignin Phenols
Compound-specific radiocarbon ( 14 C) dating often requires working with small samples of 14 C) and the mass of the procedural blanks introduced during the preparation procedures of lipid biomarkers (i.e. n -alkanoic acids) and lignin phenols. We isolated differently sized aliquots (6–151 μgC) of n -alkanoic acids and lignin phenols obtained from standard materials with known F 14 C values. Each compound class was extracted from two standard mate…
Climate variability and sea level change during the Holocene
Towards Organic Carbon Isotope Records from Stalagmites
Speleothem organic matter can be a powerful tracer for past environmental conditions and karst processes. Carbon isotope measurements (δ 13 C and 14 C) in particular can provide crucial information on the provenance and age of speleothem organic matter, but are challenging due to low concentrations of organic matter in stalagmites. Here, we present a method development study on extraction and isotopic characterization of speleothem organic matter…
Influence of Different Acid Treatments on the Radiocarbon Content Spectrum of Sedimentary Organic Matter Determined by RPO/Accelerator Mass Spectrometry
In practice, obtaining radiocarbon ( 14 C) composition of organic matter (OM) in sediments requires first removing inorganic carbon (IC) by acid-treatment. Two common treatments are acid rinsing and fumigation. Resulting 14 C content obtained by different methods can differ, but underlying causes of these differences remain elusive. To assess the influence of different acid-treatments on 14 C content of sedimentary OM, we examine the variability …
Multi-Substrate Radiocarbon Data Constrain Detrital and Reservoir Effects in Holocene Sediments of the Great Salt Lake, Utah
The radiocarbon ( 14 C) content of simultaneously deposited substrates in lacustrine archives may differ due to reservoir and detrital effects, complicating the development of age models and interpretation of proxy records. Multi-substrate 14 C studies quantifying these effects remain rare, however, particularly for large, terminal lake systems, which are excellent recorders of regional hydroclimate change. We report 14 C ages of carbonates, brin…
Projections for Future Radiocarbon Content in Dissolved Inorganic Carbon in Hardwater Lakes
Inland water bodies contain significant amounts of carbon in the form of dissolved inorganic carbon (DIC) derived from a mixture of modern atmospheric and pre-aged sources, which needs to be considered in radiocarbon-based dating and natural isotope tracer studies. While reservoir effects in hardwater lakes are generally considered to be constant through time, a comparison of recent and historical DI 14 C data from 2013 and 1969 for Lake Constanc…
Dimensions of Radiocarbon Variability within Sedimentary Organic Matter
Organic carbon (OC) radiocarbon ( 14 C) signatures in marine surface sediments are highly variable and the causes of this heterogeneity remain ambiguous. Here, we present results from a detailed 14 C-based investigation of an Arabian Sea sediment, including measurements on organic matter (OM) in bulk sediment, specific grain size fractions, and OC decomposition products from ramped-pyrolysis-oxidation (RPO). Our results show that 14 C ages of OM …
Comparative 14 C and OSL dating of loess-paleosol sequences to evaluate post-depositional contamination of n -alkane biomarkers
There is an ongoing controversial discussion as to whether n- alkane lipid biomarkers—and organic matter of loess in general—reflect a synsedimentary paleoenvironmental/climate signal or whether they are significantly affected by postdepositional “contamination,” for example related to root and rhizomicrobial activity. In order to address this issue at our study site (the Middle to Late Weichselian loess-paleosol sequence Gleina in Saxony, German…
Comprehensive radiocarbon analysis of benzene polycarboxylic acids (BPCAs) derived from pyrogenic carbon in environmental samples
Compound-specific radiocarbon analysis (CSRA) of benzene polycarboxylic acids (BPCAs) yields molecular-level, source-specific information necessary to constrain isotopic signatures of pyrogenic carbon. However, the purification of individual BPCAs requires a multistep procedure that typically results in only microgram quantities of the target analyte(s). Such small samples are highly susceptible to contamination by extraneous carbon, which needs …
From medieval land clearing to industrial development
The Joux Valley (Swiss Jura Mountains) has a rather unusual history of human occupation, characterized by tardive but extensive settlement since the Late Middle Ages, followed by an intensive period of industrial development. To estimate the links between human activities and environmental consequences, sediment cores were retrieved in Lake Joux and submitted to a multiproxy analysis (high-resolution photographs, magnetic susceptibility, density,…
Online 13 C and 14 C Gas Measurements by EA-IRMS–AMS at ETH Zürich
Studies using carbon isotopes to understand the global carbon cycle are critical to identify and quantify sources, sinks, and processes and how humans may impact them. 13 C and 14 C are routinely measured individually; however, there is a need to develop instrumentation that can perform concurrent online analyses that can generate rich data sets conveniently and efficiently. To satisfy these requirements, we coupled an elemental analyzer to a sta…
Rapid 14 C Analysis of Dissolved Organic Carbon in Non-Saline Waters
The radiocarbon content of dissolved organic carbon (DOC) in rivers, lakes, and other non-saline waters can provide valuable information on carbon cycling dynamics in the environment. DOC is typically prepared for 14 C analysis by accelerator mass spectrometry (AMS) either by ultraviolet (UV) oxidation or by freeze-drying and sealed tube combustion. We present here a new method for the rapid analysis of 14 C of DOC using wet chemical oxidation (W…
Dissolved organic carbon loss from Yedoma permafrost amplified by ice wedge thaw
Pleistocene Yedoma permafrost contains nearly a third of all organic matter (OM) stored in circum-arctic \npermafrost and is characterized by the presence of massive ice wedges. Due to its rapid formation by \nsediment accumulation and subsequent frozen storage, Yedoma OM is relatively well preserved and highly \nbiologically available (biolabile) upon thaw. A better understanding of the processes regulating Yedoma \ndegradation is important to i…
Blank Assessment for Ultra-Small Radiocarbon Samples
The Keck Carbon Cycle AMS facility at the University of California, Irvine (KCCAMS/UCI) has developed protocols for analyzing radiocarbon in samples as small as ∼0.001 mg of carbon (C). Mass-balance background corrections for modern and 14 C-dead carbon contamination (MC and DC, respectively) can be assessed by measuring 14 C-free and modern standards, respectively, using the same sample processing techniques that are applied to unknown samples. …
Radiocarbon Dating of Alkenones from Marine Sediments
We evaluate potential process blanks associated with radiocarbon measurement of microgram to milligram quantities of alkenones at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. Two strategies to constrain the contribution of blanks to alkenone 14 C dates were followed: 1) dating of samples of known age and 2) multiple measurements of identical samples. We show that the potential contamination associated with the proc…
Radiocarbon Dating of Alkenones from Marine Sediments
The chemical and isotopic compositions of long-chain (C 36 –C 39 ) unsaturated ketones (alkenones), a unique class of algal lipids, encode surface ocean properties useful for paleoceanographic reconstruction. Recently, we have sought to extend the utility of alkenones as oceanic tracers through measurement of their radiocarbon contents. Here, we describe a method for isolation of alkenones from sediments as a compound class based on a sequence of…
Radiocarbon Dating of Alkenones from Marine Sediments
As a result of the growing use of multiple geochemical proxies to reconstruct ocean and climate changes in the past, there is an increasing need to establish temporal relationships between proxies derived from the same marine sediment record and ideally from the same core sections. Coupled proxy records of surface ocean properties, such as those based on lipid biomarkers (e.g. alkenone-derived sea surface temperature) and planktonic foraminiferal…
Radiocarbon Dating of Individual Fatty Acids as a Tool for Refining Antarctic Margin Sediment Chronologies
We have measured the radiocarbon contents of individual, solvent-extractable, short-chain (C 14 , C 16 , and C 18 ) fatty acids isolated from Ross Sea surface sediments. The corresponding 14 C ages are equivalent to that of the post-bomb dissolved inorganic carbon (DIC) reservoir. Moreover, molecular 14 C variations in surficial (upper 15 cm) sediments indicate that these compounds may prove useful for reconstructing chronologies of Antarctic mar…
Blank Assessment for Ultra-Small Radiocarbon Samples
The Keck Carbon Cycle AMS facility at the University of California, Irvine (KCCAMS/UCI) has developed protocols for analyzing radiocarbon in samples as small as ∼0.001 mg of carbon (C). Mass-balance background corrections for modern and 14 C-dead carbon contamination (MC and DC, respectively) can be assessed by measuring 14 C-free and modern standards, respectively, using the same sample processing techniques that are applied to unknown samples. …
Radiocarbon Dating of Individual Fatty Acids as a Tool for Refining Antarctic Margin Sediment Chronologies
We have measured the radiocarbon contents of individual, solvent-extractable, short-chain (C 14 , C 16 , and C 18 ) fatty acids isolated from Ross Sea surface sediments. The corresponding 14 C ages are equivalent to that of the post-bomb dissolved inorganic carbon (DIC) reservoir. Moreover, molecular 14 C variations in surficial (upper 15 cm) sediments indicate that these compounds may prove useful for reconstructing chronologies of Antarctic mar…
Rapid 14 C Analysis of Dissolved Organic Carbon in Non-Saline Waters
The radiocarbon content of dissolved organic carbon (DOC) in rivers, lakes, and other non-saline waters can provide valuable information on carbon cycling dynamics in the environment. DOC is typically prepared for 14 C analysis by accelerator mass spectrometry (AMS) either by ultraviolet (UV) oxidation or by freeze-drying and sealed tube combustion. We present here a new method for the rapid analysis of 14 C of DOC using wet chemical oxidation (W…
C Blank Assessment in Small-Scale Compound-Specific Radiocarbon Analysis of Lipid Biomarkers and Lignin Phenols
Compound-specific radiocarbon ( 14 C) dating often requires working with small samples of 14 C) and the mass of the procedural blanks introduced during the preparation procedures of lipid biomarkers (i.e. n -alkanoic acids) and lignin phenols. We isolated differently sized aliquots (6–151 μgC) of n -alkanoic acids and lignin phenols obtained from standard materials with known F 14 C values. Each compound class was extracted from two standard mate…
Dimensions of Radiocarbon Variability within Sedimentary Organic Matter
Organic carbon (OC) radiocarbon ( 14 C) signatures in marine surface sediments are highly variable and the causes of this heterogeneity remain ambiguous. Here, we present results from a detailed 14 C-based investigation of an Arabian Sea sediment, including measurements on organic matter (OM) in bulk sediment, specific grain size fractions, and OC decomposition products from ramped-pyrolysis-oxidation (RPO). Our results show that 14 C ages of OM …
Online 13 C and 14 C Gas Measurements by EA-IRMS–AMS at ETH Zürich
Studies using carbon isotopes to understand the global carbon cycle are critical to identify and quantify sources, sinks, and processes and how humans may impact them. 13 C and 14 C are routinely measured individually; however, there is a need to develop instrumentation that can perform concurrent online analyses that can generate rich data sets conveniently and efficiently. To satisfy these requirements, we coupled an elemental analyzer to a sta…
Radiocarbon Dating of Alkenones from Marine Sediments
We evaluate potential process blanks associated with radiocarbon measurement of microgram to milligram quantities of alkenones at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. Two strategies to constrain the contribution of blanks to alkenone 14 C dates were followed: 1) dating of samples of known age and 2) multiple measurements of identical samples. We show that the potential contamination associated with the proc…
Radiocarbon Dating of Alkenones from Marine Sediments
The chemical and isotopic compositions of long-chain (C 36 –C 39 ) unsaturated ketones (alkenones), a unique class of algal lipids, encode surface ocean properties useful for paleoceanographic reconstruction. Recently, we have sought to extend the utility of alkenones as oceanic tracers through measurement of their radiocarbon contents. Here, we describe a method for isolation of alkenones from sediments as a compound class based on a sequence of…
Influence of Different Acid Treatments on the Radiocarbon Content Spectrum of Sedimentary Organic Matter Determined by RPO/Accelerator Mass Spectrometry
In practice, obtaining radiocarbon ( 14 C) composition of organic matter (OM) in sediments requires first removing inorganic carbon (IC) by acid-treatment. Two common treatments are acid rinsing and fumigation. Resulting 14 C content obtained by different methods can differ, but underlying causes of these differences remain elusive. To assess the influence of different acid-treatments on 14 C content of sedimentary OM, we examine the variability …
Multi-Substrate Radiocarbon Data Constrain Detrital and Reservoir Effects in Holocene Sediments of the Great Salt Lake, Utah
The radiocarbon ( 14 C) content of simultaneously deposited substrates in lacustrine archives may differ due to reservoir and detrital effects, complicating the development of age models and interpretation of proxy records. Multi-substrate 14 C studies quantifying these effects remain rare, however, particularly for large, terminal lake systems, which are excellent recorders of regional hydroclimate change. We report 14 C ages of carbonates, brin…
From medieval land clearing to industrial development
The Joux Valley (Swiss Jura Mountains) has a rather unusual history of human occupation, characterized by tardive but extensive settlement since the Late Middle Ages, followed by an intensive period of industrial development. To estimate the links between human activities and environmental consequences, sediment cores were retrieved in Lake Joux and submitted to a multiproxy analysis (high-resolution photographs, magnetic susceptibility, density,…
Radiocarbon Dating of Individual Fatty Acids as a Tool for Refining Antarctic Margin Sediment Chronologies
We have measured the radiocarbon contents of individual, solvent-extractable, short-chain (C 14 , C 16 , and C 18 ) fatty acids isolated from Ross Sea surface sediments. The corresponding 14 C ages are equivalent to that of the post-bomb dissolved inorganic carbon (DIC) reservoir. Moreover, molecular 14 C variations in surficial (upper 15 cm) sediments indicate that these compounds may prove useful for reconstructing chronologies of Antarctic mar…
Radiocarbon Dating of Alkenones from Marine Sediments
We evaluate potential process blanks associated with radiocarbon measurement of microgram to milligram quantities of alkenones at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. Two strategies to constrain the contribution of blanks to alkenone 14 C dates were followed: 1) dating of samples of known age and 2) multiple measurements of identical samples. We show that the potential contamination associated with the proc…
Radiocarbon Dating of Alkenones from Marine Sediments
The chemical and isotopic compositions of long-chain (C 36 –C 39 ) unsaturated ketones (alkenones), a unique class of algal lipids, encode surface ocean properties useful for paleoceanographic reconstruction. Recently, we have sought to extend the utility of alkenones as oceanic tracers through measurement of their radiocarbon contents. Here, we describe a method for isolation of alkenones from sediments as a compound class based on a sequence of…
Radiocarbon Dating of Alkenones from Marine Sediments
As a result of the growing use of multiple geochemical proxies to reconstruct ocean and climate changes in the past, there is an increasing need to establish temporal relationships between proxies derived from the same marine sediment record and ideally from the same core sections. Coupled proxy records of surface ocean properties, such as those based on lipid biomarkers (e.g. alkenone-derived sea surface temperature) and planktonic foraminiferal…
Blank Assessment for Ultra-Small Radiocarbon Samples
The Keck Carbon Cycle AMS facility at the University of California, Irvine (KCCAMS/UCI) has developed protocols for analyzing radiocarbon in samples as small as ∼0.001 mg of carbon (C). Mass-balance background corrections for modern and 14 C-dead carbon contamination (MC and DC, respectively) can be assessed by measuring 14 C-free and modern standards, respectively, using the same sample processing techniques that are applied to unknown samples. …
Dissolved organic carbon loss from Yedoma permafrost amplified by ice wedge thaw
Pleistocene Yedoma permafrost contains nearly a third of all organic matter (OM) stored in circum-arctic \npermafrost and is characterized by the presence of massive ice wedges. Due to its rapid formation by \nsediment accumulation and subsequent frozen storage, Yedoma OM is relatively well preserved and highly \nbiologically available (biolabile) upon thaw. A better understanding of the processes regulating Yedoma \ndegradation is important to i…
Rapid 14 C Analysis of Dissolved Organic Carbon in Non-Saline Waters
The radiocarbon content of dissolved organic carbon (DOC) in rivers, lakes, and other non-saline waters can provide valuable information on carbon cycling dynamics in the environment. DOC is typically prepared for 14 C analysis by accelerator mass spectrometry (AMS) either by ultraviolet (UV) oxidation or by freeze-drying and sealed tube combustion. We present here a new method for the rapid analysis of 14 C of DOC using wet chemical oxidation (W…
Comparative 14 C and OSL dating of loess-paleosol sequences to evaluate post-depositional contamination of n -alkane biomarkers
There is an ongoing controversial discussion as to whether n- alkane lipid biomarkers—and organic matter of loess in general—reflect a synsedimentary paleoenvironmental/climate signal or whether they are significantly affected by postdepositional “contamination,” for example related to root and rhizomicrobial activity. In order to address this issue at our study site (the Middle to Late Weichselian loess-paleosol sequence Gleina in Saxony, German…
Comprehensive radiocarbon analysis of benzene polycarboxylic acids (BPCAs) derived from pyrogenic carbon in environmental samples
Compound-specific radiocarbon analysis (CSRA) of benzene polycarboxylic acids (BPCAs) yields molecular-level, source-specific information necessary to constrain isotopic signatures of pyrogenic carbon. However, the purification of individual BPCAs requires a multistep procedure that typically results in only microgram quantities of the target analyte(s). Such small samples are highly susceptible to contamination by extraneous carbon, which needs …
From medieval land clearing to industrial development
The Joux Valley (Swiss Jura Mountains) has a rather unusual history of human occupation, characterized by tardive but extensive settlement since the Late Middle Ages, followed by an intensive period of industrial development. To estimate the links between human activities and environmental consequences, sediment cores were retrieved in Lake Joux and submitted to a multiproxy analysis (high-resolution photographs, magnetic susceptibility, density,…
Online 13 C and 14 C Gas Measurements by EA-IRMS–AMS at ETH Zürich
Studies using carbon isotopes to understand the global carbon cycle are critical to identify and quantify sources, sinks, and processes and how humans may impact them. 13 C and 14 C are routinely measured individually; however, there is a need to develop instrumentation that can perform concurrent online analyses that can generate rich data sets conveniently and efficiently. To satisfy these requirements, we coupled an elemental analyzer to a sta…
Projections for Future Radiocarbon Content in Dissolved Inorganic Carbon in Hardwater Lakes
Inland water bodies contain significant amounts of carbon in the form of dissolved inorganic carbon (DIC) derived from a mixture of modern atmospheric and pre-aged sources, which needs to be considered in radiocarbon-based dating and natural isotope tracer studies. While reservoir effects in hardwater lakes are generally considered to be constant through time, a comparison of recent and historical DI 14 C data from 2013 and 1969 for Lake Constanc…
Dimensions of Radiocarbon Variability within Sedimentary Organic Matter
Organic carbon (OC) radiocarbon ( 14 C) signatures in marine surface sediments are highly variable and the causes of this heterogeneity remain ambiguous. Here, we present results from a detailed 14 C-based investigation of an Arabian Sea sediment, including measurements on organic matter (OM) in bulk sediment, specific grain size fractions, and OC decomposition products from ramped-pyrolysis-oxidation (RPO). Our results show that 14 C ages of OM …
Climate variability and sea level change during the Holocene
Towards Organic Carbon Isotope Records from Stalagmites
Speleothem organic matter can be a powerful tracer for past environmental conditions and karst processes. Carbon isotope measurements (δ 13 C and 14 C) in particular can provide crucial information on the provenance and age of speleothem organic matter, but are challenging due to low concentrations of organic matter in stalagmites. Here, we present a method development study on extraction and isotopic characterization of speleothem organic matter…
Influence of Different Acid Treatments on the Radiocarbon Content Spectrum of Sedimentary Organic Matter Determined by RPO/Accelerator Mass Spectrometry
In practice, obtaining radiocarbon ( 14 C) composition of organic matter (OM) in sediments requires first removing inorganic carbon (IC) by acid-treatment. Two common treatments are acid rinsing and fumigation. Resulting 14 C content obtained by different methods can differ, but underlying causes of these differences remain elusive. To assess the influence of different acid-treatments on 14 C content of sedimentary OM, we examine the variability …
Multi-Substrate Radiocarbon Data Constrain Detrital and Reservoir Effects in Holocene Sediments of the Great Salt Lake, Utah
The radiocarbon ( 14 C) content of simultaneously deposited substrates in lacustrine archives may differ due to reservoir and detrital effects, complicating the development of age models and interpretation of proxy records. Multi-substrate 14 C studies quantifying these effects remain rare, however, particularly for large, terminal lake systems, which are excellent recorders of regional hydroclimate change. We report 14 C ages of carbonates, brin…
Source forensics of n-alkanes and n-fatty acids in urban aerosols using compound specific radiocarbon/stable carbon isotopic composition
n -Alkanes and fatty acids are important molecular markers for the source apportionment of organic matter in the atmosphere. Traditional approaches to date have mostly relied upon the source-specific differences in their molecular distributions and carbon preference index. Alternatively, we demonstrate here the use of stable carbon and radiocarbon isotopic composition ( δ 13 C and Δ 14 C, respectively) of n -alkanes and n -fatty acids in aerosols…
C Blank Assessment in Small-Scale Compound-Specific Radiocarbon Analysis of Lipid Biomarkers and Lignin Phenols
Compound-specific radiocarbon ( 14 C) dating often requires working with small samples of 14 C) and the mass of the procedural blanks introduced during the preparation procedures of lipid biomarkers (i.e. n -alkanoic acids) and lignin phenols. We isolated differently sized aliquots (6–151 μgC) of n -alkanoic acids and lignin phenols obtained from standard materials with known F 14 C values. Each compound class was extracted from two standard mate…
Preferential export of permafrost-derived organic matter as retrogressive thaw slumping intensifies
Enhanced warming of the Northern high latitudes has intensified thermokarst processes throughout the permafrost zone. Retrogressive thaw slumps (RTS), where thaw-driven erosion caused by ground ice melt creates terrain disturbances extending over tens of hectares, represent particularly dynamic thermokarst features. Biogeochemical transformation of the mobilized substrate may release CO 2 to the atmosphere and impact downstream ecosystems, yet it…
Seasonal variability in particulate organic carbon degradation in the Kolyma River, Siberia
Major Arctic rivers are undergoing changes due to climate warming with higher discharge and increased amounts of solutes and organic carbon (OC) draining into rivers and coastal seas. Permafrost thaw mobilizes previously frozen OC to the fluvial network where it can be degraded into greenhouse gases and emitted to the atmosphere. Degradation of OC during downstream transport, especially of the particulate OC (POC), is however poorly characterized…
Mineralogy as a potential driver of irregular radiocarbon patterns among Icelandic fluvial carbon pools
Fluvial export of organic carbon (OC) from the terrestrial biosphere to the ocean forms a key component of the global carbon cycle. Carbon sources and transformations along the land–ocean aquatic continuum are dynamic with a complex interplay between particulate and dissolved organic and inorganic carbon pools (POC, DOC, DIC). Radiocarbon dating serves as a valuable tool, providing crucial insights into turnover and residence times within these p…
A Universal Gas Interface for Simultaneous 14 C and Δ 13 C Measurements
While simultaneous radiocarbon and δ 13 C measurements have been available for organic materials (by accelerator mass spectrometry, AMS, and isotope ratio mass spectrometry, IRMS, respectively), this has not been possible for carbonates until now. Using an existing interface for gas ion source AMS measurements, we developed a prototype for a universal gas interface that allows simultaneous measurement of both carbon isotope ratios from potentiall…
Pollen 14 C dating compared with established dating methods
Radiocarbon ( 14 C) dating is a powerful tool for establishing reliable chronologies for proxy records recovered from environmental archives, including lacustrine sediments. However, lacustrine sediments are often limited with respect to availability of material such as terrestrial macrofossils that are traditionally targeted for 14 C dating. Flow cytometry, in combination with physicochemical preprocessing, is an emerging technique for the isola…
Towards online ramped oxidation (ORO)-AMS for thermal dissection and serial radiocarbon analysis of complex organic matter
By constraining organic carbon (OC) turnover times and ages, radiocarbon ( 14 C) analysis has become a crucial tool to study the global carbon cycle. However, commonly used “bulk” measurements yield average turnover times, masking age variability within complex OC mixtures. One method to unravel intra-sample age distributions is ramped oxidation, in which OC is oxidized with the aid of oxygen at increasing temperatures. The resulting CO 2 is coll…
Geology (19 obras) · Geology and Paleoclimatology Research (19 obras) · Chemistry (17 obras) · Isotope Analysis in Ecology (17 obras) · Radiocarbon dating (17 obras) · Environmental Chemistry (14 obras) · Paleontology (12 obras) · Carbon fibers (11 obras) · Oceanography (11 obras) · Environmental Science (9 obras)