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Pan Y, Li F, Lin W, Zhou Y, Song X. Quantifying isotope parameters associated with carbonyl-water oxygen exchange during sucrose translocation in tree phloem. THE NEW PHYTOLOGIST 2024; 242:975-987. [PMID: 38439696 DOI: 10.1111/nph.19654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/19/2024] [Indexed: 03/06/2024]
Abstract
Stable oxygen isotope ratio of tree-ring α-cellulose (δ18Ocel) yields valuable information on many aspects of tree-climate interactions. However, our current understanding of the mechanistic controls on δ18Ocel is incomplete, with a knowledge gap existent regarding the fractionation effect characterizing carbonyl-water oxygen exchange during sucrose translocation from leaf to phloem. To address this insufficiency, we set up an experimental system integrating a vapor 18O-labeling feature to manipulate leaf-level isotopic signatures in tree saplings enclosed within whole-canopy gas-exchange cuvettes. We applied this experimental system to three different tree species to determine their respective relationships between 18O enrichment of sucrose in leaf lamina (Δ18Ol_suc) and petiole phloem (Δ18Ophl_suc) under environmentally/physiologically stable conditions. Based on the determined Δ18Ophl_suc-Δ18Ol_suc relationships, we estimated that on average, at least 25% of the oxygen atoms in sucrose undergo isotopic exchange with water along the leaf-to-phloem translocation path and that the biochemical fractionation factor accounting for such exchange is c. 34‰, markedly higher than the conventionally assumed value of 27‰. Our study represents a significant step toward quantitative elucidation of the oxygen isotope dynamics during sucrose translocation in trees. This has important implications with respect to improving the δ18Ocel model and its related applications in paleoclimatic and ecophysiological contexts.
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Affiliation(s)
- Yonghui Pan
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Fang Li
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
- Huzhou Vocational & Technical College, Huzhou, 313000, China
| | - Wen Lin
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Youping Zhou
- Department of Marine Science and Technology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xin Song
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
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Rani A, Zhao Y, Yan Q, Wang Y, Ma R, Zhu Z, Wang B, Li T, Zhou X, Hocart CH, Zhou Y. On the Chemical Purity and Oxygen Isotopic Composition of α-Cellulose Extractable from Higher Plants and the Implications for Climate, Metabolic, and Physiological Studies. Anal Chem 2023; 95:4871-4879. [PMID: 36878693 DOI: 10.1021/acs.analchem.2c04384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
The 18O/16O ratio of α-cellulose in land plants has proved of interest for climate, environmental, physiological, and metabolic studies. Reliable application of such a ratio may be compromised by the presence of hemicellulose impurities in the α-cellulose product obtainable with current extraction methods, as the impurities are known to be isotopically different from that of the α-cellulose. We first compared the quality of hydrolysates of "α-cellulose products" obtained with four representative extraction methods (Jayme and Wise; Brendel; Zhou; Loader) and quantified the hemicellulose-derived non-glucose sugars in the α-cellulose products from 40 land grass species using gas chromatography-mass spectrometry (GC/MS). Second, we performed compound-specific isotope analysis of the hydrolysates using GC/Pyrolysis/IRMS. These results were then compared with the bulk isotope analysis using EA/Pyrolysis/IRMS of the α-cellulose products. We found that overall, the Zhou method afforded the highest purity α-cellulose as judged by the minimal presence of lignin and the second-lowest presence of non-glucose sugars. Isotopic analysis then showed that the O-2-O-6 of the α-cellulose glucosyl units were all depleted in 18O by 0.0-4.3 mUr (average, 1.9 mUr) in a species-dependent manner relative to the α-cellulose products. The positive isotopic bias of using the α-cellulose product instead of the glucosyl units stems mainly from the fact that the pentoses that dominate hemicellulose contamination in the α-cellulose product are relatively enriched in 18O (compared to hexoses) as they inherit only the relatively 18O-enriched O-2-O-5 moiety of sucrose, the common precursor of pentoses and hexoses in cellulose, and are further enriched in 18O by the (incomplete) hydrolysis.
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Affiliation(s)
- Andleeb Rani
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Yu Zhao
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Qiulin Yan
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Ying Wang
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Ran Ma
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Zhenyu Zhu
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Bo Wang
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Ting Li
- College of Science and Engineering, ARC Centre of Excellence for Australian Biodiversity and Heritage, Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns 4878, Australia
| | - Xiuwen Zhou
- Isotopomics in Chemical & Biological Oceanography (ICBO), Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Charles H Hocart
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
- Research School of Biology, Australian National University, Acton 2601, Australian Capital Territory, Australia
| | - Youping Zhou
- Isotopomics in Chemical Biology (ICB), School of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
- Isotopomics in Chemical & Biological Oceanography (ICBO), Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
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3
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Leppä K, Tang Y, Ogée J, Launiainen S, Kahmen A, Kolari P, Sahlstedt E, Saurer M, Schiestl‐Aalto P, Rinne‐Garmston KT. Explicitly accounting for needle sugar pool size crucial for predicting intra-seasonal dynamics of needle carbohydrates δ 18 O and δ 13 C. THE NEW PHYTOLOGIST 2022; 236:2044-2060. [PMID: 35575976 PMCID: PMC9795997 DOI: 10.1111/nph.18227] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 05/07/2022] [Indexed: 05/14/2023]
Abstract
We explore needle sugar isotopic compositions (δ18 O and δ13 C) in boreal Scots pine (Pinus sylvestris) over two growing seasons. A leaf-level dynamic model driven by environmental conditions and based on current understanding of isotope fractionation processes was built to predict δ18 O and δ13 C of two hierarchical needle carbohydrate pools, accounting for the needle sugar pool size and the presence of an invariant pinitol pool. Model results agreed well with observed needle water δ18 O, δ18 O and δ13 C of needle water-soluble carbohydrates (sugars + pinitol), and needle sugar δ13 C (R2 = 0.95, 0.84, 0.60, 0.73, respectively). Relative humidity (RH) and intercellular to ambient CO2 concentration ratio (Ci /Ca ) were the dominant drivers of δ18 O and δ13 C variability, respectively. However, the variability of needle sugar δ18 O and δ13 C was reduced on diel and intra-seasonal timescales, compared to predictions based on instantaneous RH and Ci /Ca , due to the large needle sugar pool, which caused the signal formation period to vary seasonally from 2 d to more than 5 d. Furthermore, accounting for a temperature-sensitive biochemical 18 O-fractionation factor and mesophyll resistance in 13 C-discrimination were critical. Interpreting leaf-level isotopic signals requires understanding on time integration caused by mixing in the needle sugar pool.
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Affiliation(s)
- Kersti Leppä
- Natural Resources Institute Finland00790HelsinkiFinland
| | - Yu Tang
- Natural Resources Institute Finland00790HelsinkiFinland
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research (INAR)/Forest SciencesUniversity of Helsinki00014HelsinkiFinland
| | | | | | - Ansgar Kahmen
- Department of Environmental Sciences – BotanyUniversity of Basel4056BaselSwitzerland
| | - Pasi Kolari
- Faculty of Science, Institute for Atmospheric and Earth System Research (INAR)/PhysicsUniversity of Helsinki00014HelsinkiFinland
| | | | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for ForestSnow and Landscape Research (WSL)8903BirmensdorfSwitzerland
| | - Pauliina Schiestl‐Aalto
- Faculty of Science, Institute for Atmospheric and Earth System Research (INAR)/PhysicsUniversity of Helsinki00014HelsinkiFinland
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Lehmann MM, Goldsmith GR, Mirande-Ney C, Weigt RB, Schönbeck L, Kahmen A, Gessler A, Siegwolf RTW, Saurer M. The 18 O-signal transfer from water vapour to leaf water and assimilates varies among plant species and growth forms. PLANT, CELL & ENVIRONMENT 2020; 43:510-523. [PMID: 31732962 DOI: 10.1111/pce.13682] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 11/11/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
The 18 O signature of atmospheric water vapour (δ18 OV ) is known to be transferred via leaf water to assimilates. It remains, however, unclear how the 18 O-signal transfer differs among plant species and growth forms. We performed a 9-hr greenhouse fog experiment (relative humidity ≥ 98%) with 18 O-depleted water vapour (-106.7‰) on 140 plant species of eight different growth forms during daytime. We quantified the 18 O-signal transfer by calculating the mean residence time of O in leaf water (MRTLW ) and sugars (MRTSugars ) and related it to leaf traits and physiological drivers. MRTLW increased with leaf succulence and thickness, varying between 1.4 and 10.8 hr. MRTSugars was shorter in C3 and C4 plants than in crassulacean acid metabolism (CAM) plants and highly variable among species and growth forms; MRTSugars was shortest for grasses and aquatic plants, intermediate for broadleaf trees, shrubs, and herbs, and longest for conifers, epiphytes, and succulents. Sucrose was more sensitive to δ18 OV variations than other assimilates. Our comprehensive study shows that plant species and growth forms vary strongly in their sensitivity to δ18 OV variations, which is important for the interpretation of δ18 O values in plant organic material and compounds and thus for the reconstruction of climatic conditions and plant functional responses.
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Affiliation(s)
- Marco M Lehmann
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, 8903, Switzerland
| | - Gregory R Goldsmith
- Schmid College of Science and Technology, Chapman University, Orange, CA, 92866
| | | | - Rosemarie B Weigt
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, 8903, Switzerland
| | - Leonie Schönbeck
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, 8903, Switzerland
| | - Ansgar Kahmen
- Department of Environmental Sciences-Botany, University of Basel, Basel, 4056, Switzerland
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, 8903, Switzerland
| | - Rolf T W Siegwolf
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, 8903, Switzerland
| | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, 8903, Switzerland
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Lehmann MM, Goldsmith GR, Schmid L, Gessler A, Saurer M, Siegwolf RTW. The effect of 18 O-labelled water vapour on the oxygen isotope ratio of water and assimilates in plants at high humidity. THE NEW PHYTOLOGIST 2018; 217:105-116. [PMID: 28940549 DOI: 10.1111/nph.14788] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/12/2017] [Indexed: 06/07/2023]
Abstract
Our understanding of how temporal variations of atmospheric water vapour and its isotopic composition (δ18 OV ) influence water and assimilates in plants remains limited, restricting our ability to use δ18 O as a tracer of ecophysiological processes. We exposed oak (Quercus robur) saplings under wet and dry soil moisture conditions to 18 O-depleted water vapour (c. - 200‰) at high relative humidity (c. 93%) for 5 h, simulating a fog event. We then traced the step change in δ18 OV into water and assimilates (e.g. sucrose, hexoses, quercitol and starch) in the leaf lamina, main veins and twigs over 24 h. The immediate δ18 OV effect was highest for δ18 O of leaf lamina water, but 40% lower on δ18 O of main vein water. To a smaller extent, we also observed changes in δ18 O of twig xylem water. Depending on the individual assimilation rate of each plant, the 18 O-label was partitioned among different assimilates, with highest changes in δ18 O of starch/sucrose and lowest in δ18 O of quercitol. Additionally, 18 O-label partitioning and allocation towards leaf starch and twig phloem sugars was influenced by the plant water status. Our results have important implications for water isotope heterogeneity in plants and for our understanding of how the δ18 O signal is incorporated into biomarkers.
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Affiliation(s)
- Marco M Lehmann
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
| | - Gregory R Goldsmith
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland
- Schmid College of Science and Technology, Chapman University, Orange, CA, 92866, USA
| | - Lola Schmid
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
| | - Matthias Saurer
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
| | - Rolf T W Siegwolf
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
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Blees J, Saurer M, Siegwolf RTW, Ulevicius V, Prevôt ASH, Dommen J, Lehmann MM. Oxygen isotope analysis of levoglucosan, a tracer of wood burning, in experimental and ambient aerosol samples. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:2101-2108. [PMID: 28972298 DOI: 10.1002/rcm.8005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/21/2017] [Accepted: 09/25/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Levoglucosan is formed from cellulose during biomass burning. It is therefore often used as a specific tracer to quantify the contribution of wood burning to the aerosol loading. The stable oxygen isotope composition (δ18 O value) of biomass is determined by the water cycle and varies regionally, and hence the δ18 O value of levoglucosan could help to identify source regions of organic aerosols. METHODS After solvent extraction of the organic fraction and concentration steps, a recently developed methylation derivatisation technique was applied on experimental (i.e. controlled wood-burning experiments) and on ambient aerosol samples from Switzerland and Lithuania. The method achieves sufficient compound separation for isotope analysis in atmospheric particulate matter, enabling δ18 O analysis of levoglucosan by gas chromatography/pyrolysis-isotope ratio mass spectrometry (GC/Pyr-IRMS), with a precision better than 1.0 ‰ and an accuracy of 0.3 ‰. RESULTS The δ18 O value of the levoglucosan released during controlled wood-burning experiments was not significantly different from the cellulose δ18 O values, which implies very little or no isotope fractionation during wood burning under the given conditions. While the δ18 O values of levoglucosan in Swiss samples were as expected for the source region, those in Lithuania were 1-4 ‰ lower than expected. This may be due to differences in vegetation (grass vs wood) or burning conditions (high vs low temperatures). CONCLUSIONS Low oxygen isotope fractionation between cellulose and levoglucosan and clear differences in levoglucosan δ18 O values between the Swiss and Lithuanian ambient samples demonstrate that our new method is useful for source appointment studies on wood-burning-derived aerosols.
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Affiliation(s)
- Jan Blees
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - Matthias Saurer
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen, Switzerland
- Forest Dynamics, Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Rolf T W Siegwolf
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen, Switzerland
- Forest Dynamics, Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Vidmantas Ulevicius
- Department of Environmental Research, SRI Center for Physical Sciences and Technology, Vilnius, Lithuania
| | - André S H Prevôt
- Forest Dynamics, Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Josef Dommen
- Forest Dynamics, Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), Birmensdorf, Switzerland
| | - Marco M Lehmann
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen, Switzerland
- Forest Dynamics, Swiss Federal Institute for Forest, Snow, and Landscape Research (WSL), Birmensdorf, Switzerland
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Lehmann MM, Gamarra B, Kahmen A, Siegwolf RTW, Saurer M. Oxygen isotope fractionations across individual leaf carbohydrates in grass and tree species. PLANT, CELL & ENVIRONMENT 2017; 40:1658-1670. [PMID: 28436078 DOI: 10.1111/pce.12974] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 04/12/2017] [Accepted: 04/14/2017] [Indexed: 06/07/2023]
Abstract
Almost no δ18 O data are available for leaf carbohydrates, leaving a gap in the understanding of the δ18 O relationship between leaf water and cellulose. We measured δ18 O values of bulk leaf water (δ18 OLW ) and individual leaf carbohydrates (e.g. fructose, glucose and sucrose) in grass and tree species and δ18 O of leaf cellulose in grasses. The grasses were grown under two relative humidity (rH) conditions. Sucrose was generally 18 O-enriched compared with hexoses across all species with an apparent biosynthetic fractionation factor (εbio ) of more than 27‰ relative to δ18 OLW , which might be explained by isotopic leaf water and sucrose synthesis gradients. δ18 OLW and δ18 O values of carbohydrates and cellulose in grasses were strongly related, indicating that the leaf water signal in carbohydrates was transferred to cellulose (εbio = 25.1‰). Interestingly, damping factor pex px , which reflects oxygen isotope exchange with less enriched water during cellulose synthesis, responded to rH conditions if modelled from δ18 OLW but not if modelled directly from δ18 O of individual carbohydrates. We conclude that δ18 OLW is not always a good substitute for δ18 O of synthesis water due to isotopic leaf water gradients. Thus, compound-specific δ18 O analyses of individual carbohydrates are helpful to better constrain (post-)photosynthetic isotope fractionation processes in plants.
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Affiliation(s)
- Marco M Lehmann
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen, CH-5232, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Bruno Gamarra
- Institute of Agricultural Sciences, ETH Zurich, Zurich, CH-8092, Switzerland
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, University of Basel, Basel, CH-4056, Switzerland
| | - Rolf T W Siegwolf
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen, CH-5232, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
| | - Matthias Saurer
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), Villigen, CH-5232, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, CH-8903, Switzerland
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Hitzfeld KL, Gehre M, Richnow HH. Evaluation of the performance of high temperature conversion reactors for compound-specific oxygen stable isotope analysis. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2017; 53:116-133. [PMID: 27686404 DOI: 10.1080/10256016.2016.1215983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
In this study conversion conditions for oxygen gas chromatography high temperature conversion (HTC) isotope ratio mass spectrometry (IRMS) are characterised using qualitative mass spectrometry (IonTrap). It is shown that physical and chemical properties of a given reactor design impact HTC and thus the ability to accurately measure oxygen isotope ratios. Commercially available and custom-built tube-in-tube reactors were used to elucidate (i) by-product formation (carbon dioxide, water, small organic molecules), (ii) 2nd sources of oxygen (leakage, metal oxides, ceramic material), and (iii) required reactor conditions (conditioning, reduction, stability). The suitability of the available HTC approach for compound-specific isotope analysis of oxygen in volatile organic molecules like methyl tert-butyl ether is assessed. Main problems impeding accurate analysis are non-quantitative HTC and significant carbon dioxide by-product formation. An evaluation strategy combining mass spectrometric analysis of HTC products and IRMS 18O/16O monitoring for future method development is proposed.
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Affiliation(s)
- Kristina L Hitzfeld
- a Department of Isotope Biogeochemistry , Helmholtz-Centre for Environmental Research - UFZ , Leipzig , Germany
| | - Matthias Gehre
- a Department of Isotope Biogeochemistry , Helmholtz-Centre for Environmental Research - UFZ , Leipzig , Germany
| | - Hans-Hermann Richnow
- a Department of Isotope Biogeochemistry , Helmholtz-Centre for Environmental Research - UFZ , Leipzig , Germany
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9
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Liquid Biopsies for Cancer: Coming to a Patient near You. J Clin Med 2017; 6:jcm6010003. [PMID: 28054963 PMCID: PMC5294956 DOI: 10.3390/jcm6010003] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/15/2016] [Accepted: 12/18/2016] [Indexed: 12/14/2022] Open
Abstract
The use of circulating tumor DNA (ctDNA) as a novel and non-invasive test for the diagnosis and surveillance of cancer is a rapidly growing area of interest, with sequencing of ctDNA acting as a potential surrogate for tissue biopsy. Circulating tumor DNA has been detected incidentally during noninvasive prenatal testing and additionally in more than 75% of known cancer patients participating in ctDNA studies evaluating its sensitivity. In the setting of mutation-based targeted tumor therapy, it shows a concordance rate >80% when compared with gold-standard tissue biopsies. Through ctDNA detection and sequencing, a simple blood test becomes a liquid biopsy for cancer, surveying a patient’s entire circulation with the goal of early detection, prognostic information, personalized therapy options, and tracking for recurrence or resistance, all with fewer or no tissue biopsies. Given the recent first-ever FDA approval of a liquid biopsy, it is important for clinicians to be aware of the rapid advancements likely to bring these tests into our practices soon. Here we review the biology, clinical implications, and recent advances in circulating tumor DNA analysis.
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