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Cui Y, Xiao Q, Wang Z, Zhang Q, Liu Y, Hao W, Jiang J, Meng Q, Wei X. 1,2-bis(2,4,6-tribromophenoxy) ethane, a novel brominated flame retardant, disrupts intestinal barrier function via the IRX3/NOS2 axis in rat small intestine. J Hazard Mater 2024; 461:132597. [PMID: 37804762 DOI: 10.1016/j.jhazmat.2023.132597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/15/2023] [Accepted: 09/19/2023] [Indexed: 10/09/2023]
Abstract
Novel brominated flame retardants are widely used in electronics, textiles, furniture, and other products; they can enter the human body through ingestion and respiration and cause harm to the human body, and have been proven to have potential biological toxicity and accumulation effects. 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) is a widely used novel brominated flame retardant; however, there is a lack of research on its mechanism of toxicity, particularly that of intestinal toxicity. Currently, studies on the functionality of iroquois homeobox 3 (IRX3) are extremely limited. In our study, BTBPE was administered to Sprague-Dawley (SD) rats and rat small intestinal crypt epithelial cells (IEC6 cells) in vivo and in vitro, respectively, and hematoxylin and eosin (HE), immunohistochemical, Alcian blue-periodic acid-Schiff (AB-PAS), CCK8, acridine orange/ethidium bromide (AO/EB), fluorescent probes, qPCR, western blotting, and immunofluorescence analyses were performed. To explore the damage mechanism of BTBPE, we used siRNA to silence IRX3 and iNOs-IN-1 (yeast extract-peptone-wheat; YPW) to inhibit nitric oxide synthase 2 (NOS2). The results showed that BTBPE exposure caused inflammation and necroptosis in the jejunum and ileum, as well as destruction of the tight junctions and mucus layer. Moreover, BTBPE activated the IRX3/NOS2 axis both in vivo and in vitro. Silencing IRX3 or inhibiting NOS2 inhibits necroptosis and restores tight junctions in IEC6 cells. In conclusion, our study found that in the jejunum, ileum, and IEC6 cells, BTBPE exposure caused necroptosis and tight junction destruction by activating the IRX3/NOS2 axis. Blocking the IRX3/NOS2 axis can effectively inhibit necroptosis and restore tight junction. In addition, BTBPE exposure caused inflammation and loss of the mucous layer in the jejunum and ileum. Our study is the first to explore the mechanism of intestinal damage caused by BTBPE exposure and to discover new biological functions regulated by the IRX3/NOS2 axis, providing new research directions for necroptosis and tight junctions.
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Affiliation(s)
- Yuan Cui
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Qianqian Xiao
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Zhenyu Wang
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Qiong Zhang
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Yuetong Liu
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Weidong Hao
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Jianjun Jiang
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Qinghe Meng
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China
| | - Xuetao Wei
- Department of Toxicology, School of Public Health, Peking University, Beijing 100191, PR China; Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing 100191, PR China.
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Zimmerle D, Duggan G, Vaughn T, Bell C, Lute C, Bennett K, Kimura Y, Cardoso-Saldaña FJ, Allen DT. Modeling air emissions from complex facilities at detailed temporal and spatial resolution: The Methane Emission Estimation Tool (MEET). Sci Total Environ 2022; 824:153653. [PMID: 35151747 DOI: 10.1016/j.scitotenv.2022.153653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/29/2022] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
Recent attention to methane emissions from oil and gas infrastructure has increased interest in comparing measurements with inventory emission estimates. While measurement methods typically estimate emissions over a few periods that are seconds to hours in length, current inventory methods typically produce long-term average emission estimates. This temporal mis-alignment complicates comparisons and leads to underestimates in the uncertainty of measurement methods. This study describes a new temporally and spatially resolved inventory emission model (MEET), and demonstrates the model by application to compressor station emissions - the key facility type in midstream natural gas operations The study looks at three common facility measurement methods: tracer flux methods for measuring station emissions, the use of ethane-methane ratios for source attribution of basin-scale estimates, and the behavior of continuous monitoring for leak detection at stations. Simulation results indicate that measurement methods likely underestimate uncertainties in emission estimates by failing to account for the variability in normal facility emissions and variations in ethane/methane ratios. A tracer-based measurement campaign could estimate emissions outside the 95% confidence interval of annual emissions 30% of the time, while ethane/methane ratios could be mis-estimated by as much as 50%. Use of MEET also highlights the need to improve data reporting from measurement campaigns to better capture the temporal and spatial variation in observed emissions.
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Affiliation(s)
- Daniel Zimmerle
- Energy Institute, Colorado State University, Fort Collins, CO, USA.
| | - Gerald Duggan
- Energy Institute, Colorado State University, Fort Collins, CO, USA
| | - Timothy Vaughn
- Energy Institute, Colorado State University, Fort Collins, CO, USA
| | - Clay Bell
- Energy Institute, Colorado State University, Fort Collins, CO, USA
| | - Christopher Lute
- Energy Institute, Colorado State University, Fort Collins, CO, USA
| | - Kristine Bennett
- Energy Institute, Colorado State University, Fort Collins, CO, USA
| | - Yosuke Kimura
- Center for Energy and Environmental Resources, University of Texas at Austin, Austin, TX, USA
| | - Felipe J Cardoso-Saldaña
- Center for Energy and Environmental Resources, University of Texas at Austin, Austin, TX, USA; ExxonMobil Upstream Research Company, Spring, TX, USA
| | - David T Allen
- Center for Energy and Environmental Resources, University of Texas at Austin, Austin, TX, USA
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Jahromi KE, Nematollahi M, Krebbers R, Abbas MA, Khodabakhsh A, Harren FJM. Fourier transform and grating-based spectroscopy with a mid-infrared supercontinuum source for trace gas detection in fruit quality monitoring. Opt Express 2021; 29:12381-12397. [PMID: 33984999 DOI: 10.1364/oe.418072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
We present a multi-species trace gas sensor based on a fast, compact home-built Fourier transform spectrometer (FTS) combined with a broadband mid-infrared supercontinuum (SC) source. The spectrometer covers the spectral bandwidth of the SC source (2 - 4 µm) and provides a best spectral resolution of 1 GHz in 6 seconds. It has a detection sensitivity of a few hundred of ppbv Hz-1/2 for different gas species. We study the performance of the developed spectrometer in terms of precision, linearity, long-term stability, and multi-species detection. We use the spectrometer for measuring fruit-produced volatiles under different atmospheric conditions and compare the performance with a previously developed scanning grating-based spectrometer.
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Cardoso-Saldaña FJ, Allen DT. Projecting the Temporal Evolution of Methane Emissions from Oil and Gas Production Basins. Environ Sci Technol 2021; 55:2811-2819. [PMID: 33587606 DOI: 10.1021/acs.est.0c04224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The methane emission intensity (methane emitted/gas produced or methane emitted/methane produced) of individual unconventional oil and gas production sites in the United States has a characteristic temporal behavior, exhibiting a brief period of decrease followed by a steady increase, with intensities after 10 years of production reaching levels that are 2-10 times the 10 year production-weighted average. Temporal patterns for methane emission intensity for entire production regions are more complex. Historical production data and facility data were used with a detailed basin-wide methane emission model to simulate the collective behavior of tens of thousands of wells and associated midstream facilities. For production regions with few to no new wells being brought to production, and existing wells having reached a mature stage, as in the Barnett Shale production region in north central Texas, the methane emission intensity gradually increases, as natural gas production decreases faster than emissions decrease, following the general pattern exhibited by individual wells. In production regions that are rapidly evolving, either with large numbers of new wells being put into production or with the introduction of source-specific regulations, the behavior is more complex. In the Eagle Ford Shale, which has had both a large number of new wells and the introduction of source-specific regulations, the methane emission intensity stays within relatively narrow bounds but the distribution of sources varies. As source distributions vary, basin-wide propane-to-methane and ethane-to-methane emission ratios vary, impacting methods used in source attribution.
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Affiliation(s)
- Felipe J Cardoso-Saldaña
- Center for Energy and Environmental Resources, University of Texas at Austin, 10100 Burnett Road, Austin, Texas 78758, United States
- ExxonMobil Upstream Integrated Solutions, Spring, Texas 77389, United States
| | - David T Allen
- Center for Energy and Environmental Resources, University of Texas at Austin, 10100 Burnett Road, Austin, Texas 78758, United States
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Cardoso-Saldaña FJ, Pierce K, Chen Q, Kimura Y, Allen DT. A Searchable Database for Prediction of Emission Compositions from Upstream Oil and Gas Sources. Environ Sci Technol 2021; 55:3210-3218. [PMID: 33576222 DOI: 10.1021/acs.est.0c05925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Atmospheric emissions from oil and gas production operations are composed of multiple hydrocarbons and can have large variations in composition. Accurate estimates of emission compositions are needed to estimate the fate and impacts of emissions and to attribute emissions to sources. This work presents a database, constructed with empirical data and thermodynamic models, that can be queried to estimate hydrocarbon compositions from emission sources present at oil and gas production sites. The database can be searched for matches using between two and seven well parameters as query inputs (gas-to-oil ratio, API gravity, separator pressure, separator temperature, methane molar fraction in produced gas, ethane molar fraction of produced gas, and propane molar fraction in produced gas). Database query performance was characterized by comparing returns from database queries to a test data set. Application of the database to well parameters for tens of thousands of wells in the Barnett, Eagle Ford, and Fayetteville production regions demonstrates variations in emission compositions. Ethane to methane ratio varies by more than an order of magnitude from well to well and source to source. VOC to methane ratios are comparable in variability to ethane to methane ratios for most emission sources, but have a higher variability for emissions from flashing of liquid hydrocarbon tanks.
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Affiliation(s)
- Felipe J Cardoso-Saldaña
- Center for Energy and Environmental Resources, University of Texas at Austin, 10100 Burnet Road, Austin, Texas 78758, United States
- Now at ExxonMobil Upstream Integrated Solutions, Spring, Texas 77389, United States
| | - Kelly Pierce
- Texas Advanced Computing Center, University of Texas at Austin, 10100 Burnet Road, Austin, Texas 78758, United States
| | - Qining Chen
- Center for Energy and Environmental Resources, University of Texas at Austin, 10100 Burnet Road, Austin, Texas 78758, United States
| | - Yosuke Kimura
- Center for Energy and Environmental Resources, University of Texas at Austin, 10100 Burnet Road, Austin, Texas 78758, United States
| | - David T Allen
- Center for Energy and Environmental Resources, University of Texas at Austin, 10100 Burnet Road, Austin, Texas 78758, United States
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Menduni G, Sgobba F, Russo SD, Ranieri AC, Sampaolo A, Patimisco P, Giglio M, Passaro VM, Csutak S, Assante D, Ranieri E, Geoffrion E, Spagnolo V. Fiber-Coupled Quartz-Enhanced Photoacoustic Spectroscopy System for Methane and Ethane Monitoring in the Near-Infrared Spectral Range. Molecules 2020; 25:molecules25235607. [PMID: 33260601 PMCID: PMC7729494 DOI: 10.3390/molecules25235607] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 11/16/2022] Open
Abstract
We report on a fiber-coupled, quartz-enhanced photoacoustic spectroscopy (QEPAS) near-IR sensor for sequential detection of methane (CH4 or C1) and ethane (C2H6 or C2) in air. With the aim of developing a lightweight, compact, low-power-consumption sensor suitable for unmanned aerial vehicles (UAVs)-empowered environmental monitoring, an all-fiber configuration was designed and realized. Two laser diodes emitting at 1653.7 nm and 1684 nm for CH4 and C2H6 detection, respectively, were fiber-combined and fiber-coupled to the collimator port of the acoustic detection module. No cross talk between methane and ethane QEPAS signal was observed, and the related peak signals were well resolved. The QEPAS sensor was calibrated using gas samples generated from certified concentrations of 1% CH4 in N2 and 1% C2H6 in N2. At a lock-in integration time of 100 ms, minimum detection limits of 0.76 ppm and 34 ppm for methane and ethane were achieved, respectively. The relaxation rate of CH4 in standard air has been investigated considering the effects of H2O, N2 and O2 molecules. No influence on the CH4 QEPAS signal is expected when the water vapor concentration level present in air varies in the range 0.6–3%.
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Affiliation(s)
- Giansergio Menduni
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, 70126 Bari, Italy; (G.M.); (F.S.); (S.D.R.); (A.C.R.); (A.S.); (P.P.); (M.G.)
- Photonics Research Group, Dipartimento di Ingegneria Elettrica e dell’Informazione, Politecnico di Bari, Via Orabona 4, 70126 Bari, Italy;
| | - Fabrizio Sgobba
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, 70126 Bari, Italy; (G.M.); (F.S.); (S.D.R.); (A.C.R.); (A.S.); (P.P.); (M.G.)
| | - Stefano Dello Russo
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, 70126 Bari, Italy; (G.M.); (F.S.); (S.D.R.); (A.C.R.); (A.S.); (P.P.); (M.G.)
| | - Ada Cristina Ranieri
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, 70126 Bari, Italy; (G.M.); (F.S.); (S.D.R.); (A.C.R.); (A.S.); (P.P.); (M.G.)
- Faculty of Engineering, Uninettuno University, 00186 Rome, Italy;
| | - Angelo Sampaolo
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, 70126 Bari, Italy; (G.M.); (F.S.); (S.D.R.); (A.C.R.); (A.S.); (P.P.); (M.G.)
| | - Pietro Patimisco
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, 70126 Bari, Italy; (G.M.); (F.S.); (S.D.R.); (A.C.R.); (A.S.); (P.P.); (M.G.)
| | - Marilena Giglio
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, 70126 Bari, Italy; (G.M.); (F.S.); (S.D.R.); (A.C.R.); (A.S.); (P.P.); (M.G.)
| | - Vittorio M.N. Passaro
- Photonics Research Group, Dipartimento di Ingegneria Elettrica e dell’Informazione, Politecnico di Bari, Via Orabona 4, 70126 Bari, Italy;
| | - Sebastian Csutak
- Independent Consultant, 16300 Park Row Dr, Houston, TX 77084, USA;
| | - Dario Assante
- Faculty of Engineering, Uninettuno University, 00186 Rome, Italy;
| | - Ezio Ranieri
- Dipartimento di Biologia, Università degli Studi di Bari, Via Orabona 4, 70126 Bari, Italy;
| | - Eric Geoffrion
- Thorlabs Canada ULC, 361 Boulevard Montpellier, Saint-Laurent, QC H4N 2G6, Canada;
| | - Vincenzo Spagnolo
- PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, CNR-IFN, Via Amendola 173, 70126 Bari, Italy; (G.M.); (F.S.); (S.D.R.); (A.C.R.); (A.S.); (P.P.); (M.G.)
- Correspondence: ; Tel.: +39-080-544-2373
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Pei X, Jiang C, Chen W. Enhanced hydrolysis of 1,1,2,2-tetrachloroethane by multi-walled carbon nanotube/TiO 2 nanocomposites: The synergistic effect. Environ Pollut 2019; 255:113211. [PMID: 31541836 DOI: 10.1016/j.envpol.2019.113211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/01/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
Once released into the environment, engineered nanomaterials can significantly influence the transformation and fate of organic contaminants. To date, the abilities of composite nanomaterials to catalyze environmentally relevant abiotic transformation reactions of organic contaminants are largely unknown. Herein, we investigated the effects of two nanocomposites - consisting of anatase titanium dioxide (TiO2) with different predominantly exposed crystal facets (i.e., {101} or {001} facets) anchored to hydroxylated multi-walled carbon nanotubes (OH-MWCNT) - on the hydrolysis of 1,1,2,2-tetrachloroethane (TeCA), a common groundwater contaminant, at ambient pH (6, 7 and 8). Both OH-MWCNT/TiO2 nanocomposites were more effective in catalyzing the dehydrochlorination of TeCA than the respective component materials (i.e., bare OH-MWCNT and bare TiO2). Moreover, the synergistic effect of the two components was evident, in that the incorporation of OH-MWCNT increased the TeCA adsorption capacity of the nanocomposites, significantly enhancing the catalytic effect of the deprotonated hydroxyl and carboxyl groups on nanocomposite surfaces, which served as the main catalytic sites for TeCA hydrolysis. The findings may have important implications for the understanding of the environmental implications of composite nanomaterials and may shed light on the design of high-performance nanocomposites for enhanced contaminant removal.
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Affiliation(s)
- Xule Pei
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, China
| | - Chuanjia Jiang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, China.
| | - Wei Chen
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, China
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Chutia L, Ojha N, Girach IA, Sahu LK, Alvarado LMA, Burrows JP, Pathak B, Bhuyan PK. Distribution of volatile organic compounds over Indian subcontinent during winter: WRF-chem simulation versus observations. Environ Pollut 2019; 252:256-269. [PMID: 31153030 DOI: 10.1016/j.envpol.2019.05.097] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 05/06/2019] [Accepted: 05/19/2019] [Indexed: 06/09/2023]
Abstract
We investigate the distribution of volatile organic compounds (VOCs) over Indian subcontinent during a winter month of January 2011 combining the regional model WRF-Chem (Weather Research and Forecasting model coupled with Chemistry) with ground- and space-based observations and chemical reanalysis. WRF-Chem simulated VOCs are found to be comparable with ground-based observations over contrasting environments of the Indian subcontinent. WRF-Chem results reveal the elevated levels of VOCs (e. g. propane) over the Indo-Gangetic Plain (16 ppbv), followed by the Northeast region (9.1 ppbv) in comparison with other parts of the Indian subcontinent (1.3-8.2 ppbv). Higher relative abundances of propane (27-31%) and ethane (13-17%) are simulated across the Indian subcontinent. WRF-Chem simulated formaldehyde and glyoxal show the western coast, Eastern India and the Indo-Gangetic Plain as the regional hotspots, in a qualitative agreement with the MACC (Monitoring Atmospheric Composition and Climate) reanalysis and satellite-based observations. Lower values of RGF (ratio of glyoxal to formaldehyde <0.04) suggest dominant influences of the anthropogenic emissions on the distribution of VOCs over Indian subcontinent, except the northeastern region where higher RGF (∼0.06) indicates the role of biogenic emissions, in addition to anthropogenic emissions. Analysis of HCHO/NO2 ratio shows a NOx-limited ozone production over India, with a NOx-to-VOC transition regime over central India and IGP. The study highlights a need to initiate in situ observations of VOCs over regional hotspots (Northeast, Central India, and the western coast) based on WRF-Chem results, where different satellite-based observations differ significantly.
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Affiliation(s)
- Lakhima Chutia
- Centre for Atmospheric Studies, Dibrugarh University, Dibrugarh, India
| | - Narendra Ojha
- Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, India.
| | - Imran A Girach
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India
| | - Lokesh K Sahu
- Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, India
| | | | - John P Burrows
- Institute of Environmental Physics (IUP), University of Bremen, Bremen, Germany
| | - Binita Pathak
- Centre for Atmospheric Studies, Dibrugarh University, Dibrugarh, India; Department of Physics, Dibrugarh University, Dibrugarh, India
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Carter RAA, Liew DS, West N, Heitz A, Joll CA. Simultaneous analysis of haloacetonitriles, haloacetamides and halonitromethanes in chlorinated waters by gas chromatography-mass spectrometry. Chemosphere 2019; 220:314-323. [PMID: 30590297 DOI: 10.1016/j.chemosphere.2018.12.069] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/01/2018] [Accepted: 12/08/2018] [Indexed: 06/09/2023]
Abstract
Nitrogenous classes of disinfection by-products (DBPs), such as haloacetamides (HAAms), haloacetonitriles (HANs) and halonitromethanes (HNMs), while generally present at lower concentrations in disinfected waters than carbonaceous DBPs, such as trihalomethanes or haloacetic acids, have been shown to be more detrimental to human health. While several methods have been shown to be suitable for the analysis of some nitrogenous DBPs (N-DBPs) in disinfected waters, many are unable to quantify HAAms, the most detrimental to health of these three N-DBP classes. Here, we report the first method for the simultaneous analysis of twenty-five N-DBPs (nine HANs, nine HNMs and seven HAAms) in disinfected waters using liquid-liquid extraction followed by gas chromatography-mass spectrometry. The use of a programmable temperature vaporiser injector minimises degradation of the thermally labile HNMs, while avoiding the concomitant decreases in HANs and HAAms which occur when using lower injector temperatures. Extraction parameters, including sample pH, solvent volume, salt addition and sample pre-concentration, were investigated to determine the optimal conditions across all target N-DBPs. Good detection limits were achieved for all analytes (0.8-1.7 μg L-1) and both laboratory and instrumental runtimes were significantly reduced compared to previous methods. The method was validated for the analysis of N-DBPs in drinking, swimming pool and spa waters, and concentrations of up to 41 μg L-1 of some N-DBPs were measured in some pools.
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Affiliation(s)
- Rhys A A Carter
- Curtin Water Quality Research Centre (CWQRC), Chemistry, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Deborah S Liew
- Curtin Water Quality Research Centre (CWQRC), Chemistry, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | | | - Anna Heitz
- School of Civil and Mechanical Engineering, Curtin University, Perth, WA, Australia
| | - Cynthia A Joll
- Curtin Water Quality Research Centre (CWQRC), Chemistry, School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia.
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Teel AL, Elloy FC, Watts RJ. Persulfate activation during exertion of total oxidant demand. Chemosphere 2016; 158:184-192. [PMID: 27269993 DOI: 10.1016/j.chemosphere.2016.05.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/11/2016] [Accepted: 05/17/2016] [Indexed: 06/06/2023]
Abstract
Total oxidant demand (TOD) is a parameter that is often measured during in situ chemical oxidation (ISCO) treatability studies. The importance of TOD is based on the concept that the oxidant demand created by soil organic matter and other reduced species must be overcome before contaminant oxidation can proceed. TOD testing was originally designed for permanganate ISCO, but has also recently been applied to activated persulfate ISCO. Recent studies have documented that phenoxides activate persulfate; because soil organic matter is rich in phenolic moieties, it may activate persulfate rather than simply exerting TOD. Therefore, the generation of reactive oxygen species was investigated in three soil horizons of varied soil organic carbon content over 5-day TOD testing. Hydroxyl radical may have been generated during TOD exertion, but was likely scavenged by soil organic matter. A high flux of reductants + nucleophiles (e.g. alkyl radicals + superoxide) was generated as TOD was exerted, resulting in the rapid destruction of the probe compound hexachloroethane and the common groundwater contaminant trichloroethylene (TCE). The results of this research document that, unlike permanganate TOD, contaminant destruction does occur as TOD is exerted in persulfate ISCO systems and is promoted by the activation of persulfate by soil organic matter. Future treatability studies for persulfate ISCO should consider contaminant destruction as TOD is exerted, and the potential for persulfate activation by soil organic matter.
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Affiliation(s)
- Amy L Teel
- Department of Civil and Environmental Engineering, Washington State University, Pullman, WA, 99163-2910, USA
| | - Farah C Elloy
- Department of Civil and Environmental Engineering, Washington State University, Pullman, WA, 99163-2910, USA
| | - Richard J Watts
- Department of Civil and Environmental Engineering, Washington State University, Pullman, WA, 99163-2910, USA.
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Rice CP, McCarty GW, Bialek-Kalinski K, Zabetakis K, Torrents A, Hapeman CJ. Analysis of metolachlor ethane sulfonic acid (MESA) chirality in groundwater: A tool for dating groundwater movement in agricultural settings. Sci Total Environ 2016; 560-561:36-43. [PMID: 27093121 DOI: 10.1016/j.scitotenv.2016.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 06/05/2023]
Abstract
UNLABELLED To better address how much groundwater contributes to the loadings of pollutants from agriculture we developed a specific dating tool for groundwater residence times. This tool is based on metolachlor ethane sulfonic acid, which is a major soil metabolite of metolachlor. The chiral forms of metolachlor ethane sulfonic acid (MESA) and the chiral forms of metolachlor were examined over a 6-year period in samples of groundwater and water from a groundwater-fed stream in a riparian buffer zone. This buffer zone bordered cropland receiving annual treatments with metolachlor. Racemic (rac) metolachlor was applied for two years in the neighboring field, and subsequently S-metolachlor was used which is enriched by 88% with the S-enantiomer. Chiral analyses of the samples showed an exponential increase in abundance of the S-enantiomeric forms for MESA as a function of time for both the first order riparian buffer stream (R(2)=0.80) and for groundwater within the riparian buffer (R(2)=0.96). However, the S-enrichment values for metolachlor were consistently high indicating different delivery mechanisms for MESA and metolachlor. A mean residence time of 3.8years was determined for depletion of the initially-applied rac-metolachlor. This approach could be useful in dating groundwater and determining the effectiveness of conservation measures. ONE SENTENCE SUMMARY A mean residence time of 3.8years was calculated for groundwater feeding a first-order stream by plotting the timed-decay for the R-enantiomer of metolachlor ethane sulfonic acid.
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Affiliation(s)
- Clifford P Rice
- Sustainable Agricultural Systems Laboratory, Beltsville Agricultural Research Center, US Department of Agriculture, Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705-2325, United States.
| | - Gregory W McCarty
- Hydrology and Remote Sensing Laboratory, Beltsville Agricultural Research Center, US Department of Agriculture, Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705-2325, United States
| | - Krystyna Bialek-Kalinski
- Sustainable Agricultural Systems Laboratory, Beltsville Agricultural Research Center, US Department of Agriculture, Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705-2325, United States
| | - Kara Zabetakis
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD 20742-0001, United States
| | - Alba Torrents
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD 20742-0001, United States
| | - Cathleen J Hapeman
- Hydrology and Remote Sensing Laboratory, Beltsville Agricultural Research Center, US Department of Agriculture, Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705-2325, United States
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12
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Omara M, Sullivan MR, Li X, Subramanian R, Robinson AL, Presto AA. Methane Emissions from Conventional and Unconventional Natural Gas Production Sites in the Marcellus Shale Basin. Environ Sci Technol 2016; 50:2099-107. [PMID: 26824407 DOI: 10.1021/acs.est.5b05503] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
There is a need for continued assessment of methane (CH4) emissions associated with natural gas (NG) production, especially as recent advancements in horizontal drilling combined with staged hydraulic fracturing technologies have dramatically increased NG production (we refer to these wells as "unconventional" NG wells). In this study, we measured facility-level CH4 emissions rates from the NG production sector in the Marcellus region, and compared CH4 emissions between unconventional NG (UNG) well pad sites and the relatively smaller and older "conventional" NG (CvNG) sites that consist of wells drilled vertically into permeable geologic formations. A top-down tracer-flux CH4 measurement approach utilizing mobile downwind intercepts of CH4, ethane, and tracer (nitrous oxide and acetylene) plumes was performed at 18 CvNG sites (19 individual wells) and 17 UNG sites (88 individual wells). The 17 UNG sites included four sites undergoing completion flowback (FB). The mean facility-level CH4 emission rate among UNG well pad sites in routine production (18.8 kg/h (95% confidence interval (CI) on the mean of 12.0-26.8 kg/h)) was 23 times greater than the mean CH4 emissions from CvNG sites. These differences were attributed, in part, to the large size (based on number of wells and ancillary NG production equipment) and the significantly higher production rate of UNG sites. However, CvNG sites generally had much higher production-normalized CH4 emission rates (median: 11%; range: 0.35-91%) compared to UNG sites (median: 0.13%, range: 0.01-1.2%), likely resulting from a greater prevalence of avoidable process operating conditions (e.g., unresolved equipment maintenance issues). At the regional scale, we estimate that total annual CH4 emissions from 88 500 combined CvNG well pads in Pennsylvania and West Virginia (660 Gg (95% CI: 500 to 800 Gg)) exceeded that from 3390 UNG well pads by 170 Gg, reflecting the large number of CvNG wells and the comparably large fraction of CH4 lost per unit production. The new emissions data suggest that the recently instituted Pennsylvania CH4 emissions inventory substantially underestimates measured facility-level CH4 emissions by >10-40 times for five UNG sites in this study.
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Affiliation(s)
- Mark Omara
- Center for Atmospheric Particle Studies and the Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Melissa R Sullivan
- Center for Atmospheric Particle Studies and the Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Xiang Li
- Center for Atmospheric Particle Studies and the Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - R Subramanian
- Center for Atmospheric Particle Studies and the Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Allen L Robinson
- Center for Atmospheric Particle Studies and the Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Albert A Presto
- Center for Atmospheric Particle Studies and the Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
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13
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Bennett JS, Marlow DA, Nourian F, Breay J, Hammond D. Hexavalent chromium and isocyanate exposures during military aircraft painting under crossflow ventilation. J Occup Environ Hyg 2016; 13:356-371. [PMID: 26698920 PMCID: PMC4916860 DOI: 10.1080/15459624.2015.1117617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Exposure control systems performance was investigated in an aircraft painting hangar. The ability of the ventilation system and respiratory protection program to limit worker exposures was examined through air sampling during painting of F/A-18C/D strike fighter aircraft, in four field surveys. Air velocities were measured across the supply filter, exhaust filter, and hangar midplane under crossflow ventilation. Air sampling conducted during painting process phases (wipe-down, primer spraying, and topcoat spraying) encompassed volatile organic compounds, total particulate matter, Cr[VI], metals, nitroethane, and hexamethylene diisocyanate, for two worker groups: sprayers and sprayer helpers ("hosemen"). One of six methyl ethyl ketone and two of six methyl isobutyl ketone samples exceeded the short term exposure limits of 300 and 75 ppm, with means 57 ppm and 63 ppm, respectively. All 12 Cr[VI] 8-hr time-weighted averages exceeded the recommended exposure limit of 1 µg/m3, 11 out of 12 exceeded the permissible exposure limit of 5 µg/m3, and 7 out of 12 exceeded the threshold limit value of 10 µg/m3, with means 38 µg/m3 for sprayers and 8.3 µg/m3 for hosemen. Hexamethylene diisocyanate means were 5.95 µg/m3 for sprayers and 0.645 µg/m3 for hosemen. Total reactive isocyanate group--the total of monomer and oligomer as NCO group mass--showed 6 of 15 personal samples exceeded the United Kingdom Health and Safety Executive workplace exposure limit of 20 µg/m3, with means 50.9 µg/m3 for sprayers and 7.29 µg/m3 for hosemen. Several exposure limits were exceeded, reinforcing continued use of personal protective equipment. The supply rate, 94.4 m3/s (200,000 cfm), produced a velocity of 8.58 m/s (157 fpm) at the supply filter, while the exhaust rate, 68.7 m3/s (146,000 cfm), drew 1.34 m/s (264 fpm) at the exhaust filter. Midway between supply and exhaust locations, the velocity was 0.528 m/s (104 fpm). Supply rate exceeding exhaust rate created re-circulations, turbulence, and fugitive emissions, while wasting energy. Smoke releases showing more effective ventilation here than in other aircraft painting facilities carries technical feasibility relevance.
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Affiliation(s)
- James S. Bennett
- National Institute for Occupational Health, Division of Applied Research Technology, Cincinnati Ohio
| | - David A. Marlow
- National Institute for Occupational Health, Division of Applied Research Technology, Cincinnati Ohio
| | - Fariba Nourian
- National Institute for Occupational Health, Division of Applied Research Technology, Cincinnati Ohio
| | - James Breay
- U.S. Navy Medical Center San Diego, Industrial Hygiene Department, San Diego California
| | - Duane Hammond
- National Institute for Occupational Health, Division of Applied Research Technology, Cincinnati Ohio
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14
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Wang X, Guo J, Shang J, Ding L, Zhao G, Xie F, Jia Y, Qin Y, Yu Y, Chen L, Zhang S. Determination of nitroalkanes in mainstream cigarette smoke by heart-cutting multidimensional gas chromatography system coupled with mass spectrometry detection. J Chromatogr A 2015; 1424:118-26. [PMID: 26603996 DOI: 10.1016/j.chroma.2015.10.078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 10/26/2015] [Accepted: 10/26/2015] [Indexed: 12/20/2022]
Abstract
In this paper, heart-cutting two-dimensional GC/MS (GC-GC/MS) method in combination with a simple sample collection procedure was developed for the determination of 6 nitroalkanes in mainstream cigarette smoke. The method could remove large amounts of impurities on-line in the first polar column by heart-cuts and separate from the left interferences in a second mid-polar column. And the target compounds could be focused at the inlet of the second column by cryo-concentration. Compared to conventional GC/MS, GC-GC/MS achieved a lower noise level and sensitivity at least an order of magnitude higher. Furthermore, the GC-GC/MS method could avoid the false negative and false positive results that appeared in the compared conventional GC/MS analysis. By trapping the vapor phase of 20 cigarettes smoke, the LODs and LOQs of the nitroalkanes were 1.3 to 9.8 and 4.3 to 32.6ng/cigarette, respectively, and all linear correlation efficiencies were larger than 0.999. The validation results also indicate that the method has high accuracy (spiked recoveries between 84% and 102%) and good repeatability (RSD between 7.2% and 9.4%). The developed method was applied to analyze 1 Kentucky reference cigarette (3R4F) and 10 Chinese commercial brands of cigarettes. The research results indicated that nitromethane, nitroethane, 2-nitropropane and 1-nitro-n-pentane were detected in mainstream cigarette smoke, but 1-nitro-n-butane and 2-nitropropane, which were reported by one previous study, were not detected in all cigarette samples.
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Affiliation(s)
- Xiaoyu Wang
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China
| | - Jizhao Guo
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China
| | - Jingjing Shang
- Anhui Province Tobacco Quality Supervision and Test Station, Hefei, China
| | - Li Ding
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China
| | - Ge Zhao
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China
| | - Fuwei Xie
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China.
| | - Yunzhen Jia
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China
| | - Yaqiong Qin
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China
| | - Yongjie Yu
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China
| | - Li Chen
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, China
| | - Shusheng Zhang
- College of Chemistry & Molecular Engineering, Zhengzhou, China
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15
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Stacewicz T, Targowski T, Bielecki Z, Buszewski B, Ligor T, Wojtas J, Garlińska M. [Detection of disease markers in the breath using optoelectronic methods]. Pol Merkur Lekarski 2015; 39:134-141. [PMID: 26449573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
UNLABELLED Great interest of scientific community is observed recently over non-invasive tests methods dedicated to diagnose disease states using biomarkers. The ability to detect these substances in the human breath can provide valuable information about disorder of biochemical processes in the body. Breath analysis is non-invasive, painless and can provide a quick answer about the existence of the disease. In addition, the sampling process is carried out comfortably for both the patient and the medical staff. AIM The aim of the study was to present opportunity of application the optoelectronic methods for screening tests in medical diagnostics. The results of the researches carried out at the Institute of Experimental Physics, Department of Physics UW and at the Institute of Optoelectronics MUT are presented. MATERIALS AND METHODS For the detection of methane and ammonia in breath the Multipass Spectroscopic Absorption Cells (MUPASS ) were used. In the case of nitric oxide and ethane observation, Cavity Enhanced Absorption Spectroscopy (CEAS) was applied. During the investigation modern tunable and sophisticated infrared radiation sources were used: single mode diode lasers (for CH4, NH3 detection), quantum cascade laser (NO sensing), and optical parametric generator (PG711/DFG) for ethane measurements. The investigations of developed sensors were conducted with use of reference samples of biomarkers, which were prepared with gas standards generator 491M from KIN-TEK company. RESULTS Experiments showed that sensitivities of the sensors are suitable for human breath analyzing. In case of methane sensor, the detection limit (sensitivity) of ~ 0.1 ppm was obtained. This value is significantly lower than the upper limit of methane concentration in the breath of healthy humans (10 ppm). Therefore, our system well satisfies the requirements for diseases screening (e.g. intestines diseases ) and for methane monitoring in healthy human breath. Ammonia sensor is characterized with linear response in the concentration range higher than 1 ppm. The upper limit of ammonia concentration in healthy human breath is approx. 2 ppm, so this system is well suited for the determination of disease states (e.g. liver diseases). During the observation of nitrogen oxide the detection limit of 30 ppb was obtained. According to the ATS recommendation such NO detection limit is sufficient to monitor people's health state and for the detection of respiratory diseases like asthma or chronic bronchitis. For ethane detection with a wavelength of 3.348 microns the detection limit of 20 ppb was obtained. CONCLUSIONS Developed sensors are characterized by high sensitivity (ppb-level) and high selectivity, simple and fast measurement procedure. Therefore, they can be applied as medical screening tools enabling biomarkers detection in exhaled air at the molecular level.
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Affiliation(s)
| | - Tomasz Targowski
- Department of Internal Medicine, Pneumonology and Allergology, Central Clinical Hospital of the Ministry of National Defense, Military Institute of Medicine in Warsaw, Poland
| | - Zbigniew Bielecki
- Institute of Optoelectronics Military University of Technology, Warsaw
| | | | - Tomasz Ligor
- Faculty of Chemistry Nicolaus Copernicus University in Toruń
| | - Jacek Wojtas
- Institute of Optoelectronics Military University of Technology, Warsaw
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16
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Townsend-Small A, Marrero JE, Lyon DR, Simpson IJ, Meinardi S, Blake DR. Integrating Source Apportionment Tracers into a Bottom-up Inventory of Methane Emissions in the Barnett Shale Hydraulic Fracturing Region. Environ Sci Technol 2015; 49:8175-82. [PMID: 26148556 DOI: 10.1021/acs.est.5b00057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A growing dependence on natural gas for energy may exacerbate emissions of the greenhouse gas methane (CH4). Identifying fingerprints of these emissions is critical to our understanding of potential impacts. Here, we compare stable isotopic and alkane ratio tracers of natural gas, agricultural, and urban CH4 sources in the Barnett Shale hydraulic fracturing region near Fort Worth, Texas. Thermogenic and biogenic sources were compositionally distinct, and emissions from oil wells were enriched in alkanes and isotopically depleted relative to natural gas wells. Emissions from natural gas production varied in δ(13)C and alkane ratio composition, with δD-CH4 representing the most consistent tracer of natural gas sources. We integrated our data into a bottom-up inventory of CH4 for the region, resulting in an inventory of ethane (C2H6) sources for comparison to top-down estimates of CH4 and C2H6 emissions. Methane emissions in the Barnett are a complex mixture of urban, agricultural, and fossil fuel sources, which makes source apportionment challenging. For example, spatial heterogeneity in gas composition and high C2H6/CH4 ratios in emissions from conventional oil production add uncertainty to top-down models of source apportionment. Future top-down studies may benefit from the addition of δD-CH4 to distinguish thermogenic and biogenic sources.
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Affiliation(s)
- Amy Townsend-Small
- †University of Cincinnati, Departments of Geology and Geography, Cincinnati, Ohio 45221, United States
| | - Josette E Marrero
- ‡University of California, Irvine, Department of Chemistry, Irvine, California 92697, United States
| | - David R Lyon
- §Environmental Defense Fund, 301 Congress Ave., Suite 1300, Austin, Texas 78701, United States
| | - Isobel J Simpson
- ‡University of California, Irvine, Department of Chemistry, Irvine, California 92697, United States
| | - Simone Meinardi
- ‡University of California, Irvine, Department of Chemistry, Irvine, California 92697, United States
| | - Donald R Blake
- ‡University of California, Irvine, Department of Chemistry, Irvine, California 92697, United States
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17
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Smith ML, Kort EA, Karion A, Sweeney C, Herndon SC, Yacovitch TI. Airborne Ethane Observations in the Barnett Shale: Quantification of Ethane Flux and Attribution of Methane Emissions. Environ Sci Technol 2015; 49:8158-66. [PMID: 26148554 DOI: 10.1021/acs.est.5b00219] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We present high time resolution airborne ethane (C2H6) and methane (CH4) measurements made in March and October 2013 as part of the Barnett Coordinated Campaign over the Barnett Shale formation in Texas. Ethane fluxes are quantified using a downwind flight strategy, a first demonstration of this approach for C2H6. Additionally, ethane-to-methane emissions ratios (C2H6:CH4) of point sources were observationally determined from simultaneous airborne C2H6 and CH4 measurements during a survey flight over the source region. Distinct C2H6:CH4 × 100% molar ratios of 0.0%, 1.8%, and 9.6%, indicative of microbial, low-C2H6 fossil, and high-C2H6 fossil sources, respectively, emerged in observations over the emissions source region of the Barnett Shale. Ethane-to-methane correlations were used in conjunction with C2H6 and CH4 fluxes to quantify the fraction of CH4 emissions derived from fossil and microbial sources. On the basis of two analyses, we find 71-85% of the observed methane emissions quantified in the Barnett Shale are derived from fossil sources. The average ethane flux observed from the studied region of the Barnett Shale was 6.6 ± 0.2 × 10(3) kg hr(-1) and consistent across six days in spring and fall of 2013.
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Affiliation(s)
- Mackenzie L Smith
- †Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Eric A Kort
- †Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Anna Karion
- ‡CIRES, University of Colorado, Boulder, Colorado 80309, United States
- §NOAA Earth System Research Laboratory, Boulder, Colorado 80305, United States
| | - Colm Sweeney
- ‡CIRES, University of Colorado, Boulder, Colorado 80309, United States
- §NOAA Earth System Research Laboratory, Boulder, Colorado 80305, United States
| | - Scott C Herndon
- ∥Aerodyne Research, Inc., Billerica, Massachusetts 01821, United States
| | - Tara I Yacovitch
- ∥Aerodyne Research, Inc., Billerica, Massachusetts 01821, United States
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18
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Yacovitch TI, Herndon SC, Pétron G, Kofler J, Lyon D, Zahniser MS, Kolb CE. Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region. Environ Sci Technol 2015; 49:7889-95. [PMID: 25751617 DOI: 10.1021/es506352j] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Results of mobile ground-based atmospheric measurements conducted during the Barnett Shale Coordinated Campaign in spring and fall of 2013 are presented. Methane and ethane are continuously measured downwind of facilities such as natural gas processing plants, compressor stations, and production well pads. Gaussian dispersion simulations of these methane plumes, using an iterative forward plume dispersion algorithm, are used to estimate both the source location and the emission magnitude. The distribution of emitters is peaked in the 0-5 kg/h range, with a significant tail. The ethane/methane molar enhancement ratio for this same distribution is investigated, showing a peak at ∼1.5% and a broad distribution between ∼4% and ∼17%. The regional distributions of source emissions and ethane/methane enhancement ratios are examined: the largest methane emissions appear between Fort Worth and Dallas, while the highest ethane/methane enhancement ratios occur for plumes observed in the northwestern potion of the region. Individual facilities, focusing on large emitters, are further analyzed by constraining the source location.
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Affiliation(s)
- Tara I Yacovitch
- †Aerodyne Research Inc., Billerica, Massachusetts 01821, United States
| | - Scott C Herndon
- †Aerodyne Research Inc., Billerica, Massachusetts 01821, United States
| | - Gabrielle Pétron
- ‡Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
- §NOAA Earth System Research Laboratory, Boulder, Colorado 80309, United States
| | - Jonathan Kofler
- ‡Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
- §NOAA Earth System Research Laboratory, Boulder, Colorado 80309, United States
| | - David Lyon
- ∥Environmental Defense Fund, 301 Congress Ave Suite 1300, Austin, Texas 78701, United States
| | - Mark S Zahniser
- †Aerodyne Research Inc., Billerica, Massachusetts 01821, United States
| | - Charles E Kolb
- †Aerodyne Research Inc., Billerica, Massachusetts 01821, United States
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19
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Wojtas J. Application of Cavity Enhanced Absorption Spectroscopy to the Detection of Nitric Oxide, Carbonyl Sulphide, and Ethane--Breath Biomarkers of Serious Diseases. Sensors (Basel) 2015; 15:14356-69. [PMID: 26091398 PMCID: PMC4507679 DOI: 10.3390/s150614356] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 06/01/2015] [Accepted: 06/11/2015] [Indexed: 02/03/2023]
Abstract
The paper presents one of the laser absorption spectroscopy techniques as an effective tool for sensitive analysis of trace gas species in human breath. Characterization of nitric oxide, carbonyl sulphide and ethane, and the selection of their absorption lines are described. Experiments with some biomarkers showed that detection of pathogenic changes at the molecular level is possible using this technique. Thanks to cavity enhanced spectroscopy application, detection limits at the ppb-level and short measurements time (<3 s) were achieved. Absorption lines of reference samples of the selected volatile biomarkers were probed using a distributed feedback quantum cascade laser and a tunable laser system consisting of an optical parametric oscillator and difference frequency generator. Setup using the first source provided a detection limit of 30 ppb for nitric oxide and 250 ppb for carbonyl sulphide. During experiments employing a second laser, detection limits of 0.9 ppb and 0.3 ppb were obtained for carbonyl sulphide and ethane, respectively. The conducted experiments show that this type of diagnosis would significantly increase chances for effective therapy of some diseases. Additionally, it offers non-invasive and real time measurements, high sensitivity and selectivity as well as minimizing discomfort for patients. For that reason, such sensors can be used in screening for early detection of serious diseases.
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Affiliation(s)
- Jacek Wojtas
- Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., Warsaw 00-908, Poland.
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20
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Allard JP, Royall D, Kurian R, Muggli R, Jeejeebhoy KN. Effect of omega 3 fatty acids and vitamin E supplements on lipid peroxidation measured by breath ethane and pentane output: a randomized controlled trial. World Rev Nutr Diet 2015; 75:162-5. [PMID: 7871820 DOI: 10.1159/000423573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- J P Allard
- Department of Medicine, University of Toronto, Ont., Canada
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21
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Yacovitch TI, Herndon SC, Roscioli JR, Floerchinger C, McGovern RM, Agnese M, Pétron G, Kofler J, Sweeney C, Karion A, Conley SA, Kort EA, Nähle L, Fischer M, Hildebrandt L, Koeth J, McManus JB, Nelson DD, Zahniser MS, Kolb CE. Demonstration of an ethane spectrometer for methane source identification. Environ Sci Technol 2014; 48:8028-34. [PMID: 24945706 DOI: 10.1021/es501475q] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Methane is an important greenhouse gas and tropospheric ozone precursor. Simultaneous observation of ethane with methane can help identify specific methane source types. Aerodyne Ethane-Mini spectrometers, employing recently available mid-infrared distributed feedback tunable diode lasers (DFB-TDL), provide 1 s ethane measurements with sub-ppb precision. In this work, an Ethane-Mini spectrometer has been integrated into two mobile sampling platforms, a ground vehicle and a small airplane, and used to measure ethane/methane enhancement ratios downwind of methane sources. Methane emissions with precisely known sources are shown to have ethane/methane enhancement ratios that differ greatly depending on the source type. Large differences between biogenic and thermogenic sources are observed. Variation within thermogenic sources are detected and tabulated. Methane emitters are classified by their expected ethane content. Categories include the following: biogenic (<0.2%), dry gas (1-6%), wet gas (>6%), pipeline grade natural gas (<15%), and processed natural gas liquids (>30%). Regional scale observations in the Dallas/Fort Worth area of Texas show two distinct ethane/methane enhancement ratios bridged by a transitional region. These results demonstrate the usefulness of continuous and fast ethane measurements in experimental studies of methane emissions, particularly in the oil and natural gas sector.
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Affiliation(s)
- Tara I Yacovitch
- Aerodyne Research Inc., Billerica, Massachusetts 01821, United States
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22
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Schwietzke S, Griffin WM, Matthews HS, Bruhwiler LMP. Natural gas fugitive emissions rates constrained by global atmospheric methane and ethane. Environ Sci Technol 2014; 48:7714-7722. [PMID: 24945600 DOI: 10.1021/es501204c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The amount of methane emissions released by the natural gas (NG) industry is a critical and uncertain value for various industry and policy decisions, such as for determining the climate implications of using NG over coal. Previous studies have estimated fugitive emissions rates (FER)--the fraction of produced NG (mainly methane and ethane) escaped to the atmosphere--between 1 and 9%. Most of these studies rely on few and outdated measurements, and some may represent only temporal/regional NG industry snapshots. This study estimates NG industry representative FER using global atmospheric methane and ethane measurements over three decades, and literature ranges of (i) tracer gas atmospheric lifetimes, (ii) non-NG source estimates, and (iii) fossil fuel fugitive gas hydrocarbon compositions. The modeling suggests an upper bound global average FER of 5% during 2006-2011, and a most likely FER of 2-4% since 2000, trending downward. These results do not account for highly uncertain natural hydrocarbon seepage, which could lower the FER. Further emissions reductions by the NG industry may be needed to ensure climate benefits over coal during the next few decades.
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Affiliation(s)
- Stefan Schwietzke
- Department of Engineering and Public Policy, Carnegie Mellon University , Baker Hall 129, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
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Nijenhuis I, Schmidt M, Pellegatti E, Paramatti E, Richnow HH, Gargini A. A stable isotope approach for source apportionment of chlorinated ethene plumes at a complex multi-contamination events urban site. J Contam Hydrol 2013; 153:92-105. [PMID: 24077332 DOI: 10.1016/j.jconhyd.2013.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 06/14/2013] [Accepted: 06/17/2013] [Indexed: 06/02/2023]
Abstract
The stable carbon isotope composition of chlorinated aliphatic compounds such as chlorinated methanes, ethanes and ethenes was examined as an intrinsic fingerprint for apportionment of sources. A complex field site located in Ferrara (Italy), with more than 50years history of use of chlorinated aliphatic compounds, was investigated in order to assess contamination sources. Several contamination plumes were found in a complex alluvial sandy multi-aquifer system close to the river Po; sources are represented by uncontained former industrial and municipal dump sites as well as by spills at industrial areas. The carbon stable isotope signature allowed distinguishing 2 major sources of contaminants. One source of chlorinated aliphatic contaminants was strongly depleted in ¹³C (<-60‰) suggesting production lines which have used depleted methane for synthesis. The other source had typical carbon isotope compositions of >-40‰ which is commonly observed in recent production of chlorinated solvents. The degradation processes in the plumes could be traced interpreting the isotope enrichment and depletion of parent and daughter compounds, respectively. We demonstrate that, under specific production conditions, namely when highly chlorinated ethenes are produced as by-product during chloromethanes production, ¹³C depleted fingerprinting of contaminants can be obtained and this can be used to track sources and address the responsible party of the pollution in urban areas.
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Affiliation(s)
- Ivonne Nijenhuis
- Helmholtz Center for Environmental Research - UFZ, Department for Isotope Biogeochemistry, Permoserstrasse 15, 04318 Leipzig, Germany
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Chan CCH, Mundle SOC, Eckert T, Liang X, Tang S, Lacrampe-Couloume G, Edwards EA, Lollar BS. Large carbon isotope fractionation during biodegradation of chloroform by Dehalobacter cultures. Environ Sci Technol 2012; 46:10154-10160. [PMID: 22900494 DOI: 10.1021/es3010317] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Compound specific isotope analysis (CSIA) has been applied to monitor bioremediation of groundwater contaminants and provide insight into mechanisms of transformation of chlorinated ethanes. To date there is little information on its applicability for chlorinated methanes. Moreover, published enrichment factors (ε) observed during the biotic and abiotic degradation of chlorinated alkanes, such as carbon tetrachloride (CT); 1,1,1-trichloroethane (1,1,1-TCA); and 1,1-dichloroethane (1,1-DCA), range from -26.5‰ to -1.8‰ and illustrate a system where similar C-Cl bonds are cleaved but significantly different isotope enrichment factors are observed. In the current study, biotic degradation of chloroform (CF) to dichloromethane (DCM) was carried out by the Dehalobacter containing culture DHB-CF/MEL also shown to degrade 1,1,1-TCA and 1,1-DCA. The carbon isotope enrichment factor (ε) measured during biodegradation of CF was -27.5‰ ± 0.9‰, consistent with the theoretical maximum kinetic isotope effect for C-Cl bond cleavage. Unlike 1,1,1-TCA and 1,1-DCA, reductive dechlorination of CF by the Dehalobacter-containing culture shows no evidence of suppression of the intrinsic maximum kinetic isotope effect. Such a large fractionation effect, comparable to those published for cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC) suggests CSIA has significant potential to identify and monitor biodegradation of CF, as well as important implications for recent efforts to fingerprint natural versus anthropogenic sources of CF in soils and groundwater.
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Affiliation(s)
- Calvin C H Chan
- Department of Earth Sciences, University of Toronto, Toronto, ON, Canada
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Wennberg PO, Mui W, Wunch D, Kort EA, Blake DR, Atlas EL, Santoni GW, Wofsy SC, Diskin GS, Jeong S, Fischer ML. On the sources of methane to the Los Angeles atmosphere. Environ Sci Technol 2012; 46:9282-9. [PMID: 22853880 DOI: 10.1021/es301138y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We use historical and new atmospheric trace gas observations to refine the estimated source of methane (CH(4)) emitted into California's South Coast Air Basin (the larger Los Angeles metropolitan region). Referenced to the California Air Resources Board (CARB) CO emissions inventory, total CH(4) emissions are 0.44 ± 0.15 Tg each year. To investigate the possible contribution of fossil fuel emissions, we use ambient air observations of methane (CH(4)), ethane (C(2)H(6)), and carbon monoxide (CO), together with measured C(2)H(6) to CH(4) enhancement ratios in the Los Angeles natural gas supply. The observed atmospheric C(2)H(6) to CH(4) ratio during the ARCTAS (2008) and CalNex (2010) aircraft campaigns is similar to the ratio of these gases in the natural gas supplied to the basin during both these campaigns. Thus, at the upper limit (assuming that the only major source of atmospheric C(2)H(6) is fugitive emissions from the natural gas infrastructure) these data are consistent with the attribution of most (0.39 ± 0.15 Tg yr(-1)) of the excess CH(4) in the basin to uncombusted losses from the natural gas system (approximately 2.5-6% of natural gas delivered to basin customers). However, there are other sources of C(2)H(6) in the region. In particular, emissions of C(2)H(6) (and CH(4)) from natural gas seeps as well as those associated with petroleum production, both of which are poorly known, will reduce the inferred contribution of the natural gas infrastructure to the total CH(4) emissions, potentially significantly. This study highlights both the value and challenges associated with the use of ethane as a tracer for fugitive emissions from the natural gas production and distribution system.
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Affiliation(s)
- Paul O Wennberg
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States.
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Basu D, Asolekar SR. Evaluation of substrate removal kinetics for UASB reactors treating chlorinated ethanes. Environ Sci Pollut Res Int 2012; 19:2419-2427. [PMID: 22286857 DOI: 10.1007/s11356-012-0754-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 01/10/2012] [Indexed: 05/31/2023]
Abstract
PURPOSE Lack of focus on the treatment of wastewaters bearing potentially hazardous pollutants like 1,1,2 trichloroethane and 1,1,2,2 tetrachloroethane in anaerobic reactors has provided an impetus to undertake this study. The objective of this exercise was to quantify the behavior of upflow anaerobic sludge blanket reactors and predict their performance based on the overall organic substrate removal. METHODS The reactors (wastewater-bearing TCA (R2), and wastewater-bearing TeCA (R3)) were operated at different hydraulic retention times (HRTs), i.e., 36, 30, 24, 18, and 12 h corresponding to food-to-mass ratios varying in the range of 0.2–0.7 mg chemical oxygen demand (COD) mg−1 volatile suspended solids day−1. The process kinetics of substrate utilization was evaluated on the basis of experimental results, by applying three mathematical models namely first order, Grau second order, and Michaelis-Menten type kinetics. RESULTS The results showed that the lowering of HRT below 24 h resulted in reduced COD removal efficiencies and higher effluent pollutant concentrations in the reactors. The Grau second-order model was successfully applied to obtain the substrate utilization kinetics with high value of R 2 (>0.95). The Grau second-order substrate removal constant (K 2) was calculated as 1.12 and 7.53 day−1 for reactors R2 and R3, respectively. CONCLUSION This study demonstrated the suitability of Grau second-order kinetic model over other models, for predicting the performance of reactors R2 and R3, in treating wastewaters containing chlorinated ethanes under different organic and hydraulic loading conditions.
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Affiliation(s)
- Debolina Basu
- Centre for Environmental Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
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Zhao SL, Zhang J, Zhang WC. [Evaluation of uncertainty in 1,1-dichloro-1-nitroethane measurement in the air of workplace]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2012; 30:477-478. [PMID: 22931786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Haque F, Lunn J, Fang H, Smithrud D, Guo P. Real-time sensing and discrimination of single chemicals using the channel of phi29 DNA packaging nanomotor. ACS Nano 2012; 6:3251-3261. [PMID: 22458779 PMCID: PMC3337346 DOI: 10.1021/nn3001615] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A highly sensitive and reliable method to sense and identify a single chemical at extremely low concentrations and high contamination is important for environmental surveillance, homeland security, athlete drug monitoring, toxin/drug screening, and earlier disease diagnosis. This article reports a method for precise detection of single chemicals. The hub of the bacteriophage phi29 DNA packaging motor is a connector consisting of 12 protein subunits encircled into a 3.6 nm channel as a path for dsDNA to enter during packaging and to exit during infection. The connector has previously been inserted into a lipid bilayer to serve as a membrane-embedded channel. Herein we report the modification of the phi29 channel to develop a class of sensors to detect single chemicals. The lysine-234 of each protein subunit was mutated to cysteine, generating 12-SH ring lining the channel wall. Chemicals passing through this robust channel and interactions with the SH group generated extremely reliable, precise, and sensitive current signatures as revealed by single channel conductance assays. Ethane (57 Da), thymine (167 Da), and benzene (105 Da) with reactive thioester moieties were clearly discriminated upon interaction with the available set of cysteine residues. The covalent attachment of each analyte induced discrete stepwise blockage in current signature with a corresponding decrease in conductance due to the physical blocking of the channel. Transient binding of the chemicals also produced characteristic fingerprints that were deduced from the unique blockage amplitude and pattern of the signals. This study shows that the phi29 connector can be used to sense chemicals with reactive thioesters or maleimide using single channel conduction assays based on their distinct fingerprints. The results demonstrated that this channel system could be further developed into very sensitive sensing devices.
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Affiliation(s)
- Farzin Haque
- Nanobiotechnology Center, Department of Pharmaceutical Sciences, and Markey Cancer Center, University of Kentucky, Lexington, KY 40536
| | - Jennifer Lunn
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45267
| | - Huaming Fang
- Nanobiotechnology Center, Department of Pharmaceutical Sciences, and Markey Cancer Center, University of Kentucky, Lexington, KY 40536
| | - David Smithrud
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45267
| | - Peixuan Guo
- Nanobiotechnology Center, Department of Pharmaceutical Sciences, and Markey Cancer Center, University of Kentucky, Lexington, KY 40536
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Tan J, Guo S, Ma Y, He K, Yang F, Yu Y, Wang J. Characteristics of atmospheric non-methane hydrocarbons in Foshan City, China. Environ Monit Assess 2011; 183:297-305. [PMID: 21380924 DOI: 10.1007/s10661-011-1922-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 02/08/2011] [Indexed: 05/30/2023]
Abstract
Foshan is the most air-polluted city in Pearl River Delta. Non-methane hydrocarbons (NMHCs) were investigated for the first time in Foshan in winter 2008. Ethene, ethane, ethyne, propane, i-pentane, and toluene were the most abundant hydrocarbons and observed to be higher in Foshan than those in many other cities in China. Different from other cities, ethene and ethane were observed to be the two highest compounds in Foshan. Generally, the most abundant hydrocarbons showed high mixing ratios in the morning (0930-1030 hours), decreased to the lowest level in the afternoon (1430-1530 hours), and increased to higher value in the evening (1930-2030 hours). But i-pentane exhibited a different diurnal pattern with the highest level (13.4 ± 5.8 ppbv) in the afternoon, implying the acceleration of solvent evaporation resulting from higher temperature. Correlation coefficients (R(2) = 66% for n = 6 at 95% confidence level) of the individual hydrocarbons with ethyne and i-pentane indicated vehicular emissions were the main sources of ethene, propene, i-butene, isoprene, benzene and toluene, while gasoline evaporation was responsible for n-pentane, n-hexane, and n-heptane. The good correlation of most of the hydrocarbons with ethyne, indicating vehicular emissions, were the main sources of NMHCs. B/T ratio was 0.36 ± 0.06, implying vehicular emissions acted as the major contributors as well as additional emissions of toluene emitted from solvent usage. According to investigation, it also suggested that LPG leakage was the main source of propane, while NG leakage was responsible for ethane in Foshan City.
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Affiliation(s)
- Jihua Tan
- College of Earth Science, Graduate University of Chinese Academy of Sciences, Beijing, 100049, China
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Yang JP, Zhang LX, Liu T, Liu DL, Hou YG, Feng HT. [Determination of 1, 1-dichloro-l-nitroethane in air of workplaces by gas chromatography]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2011; 29:629-631. [PMID: 22335170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To establish a gas chromatography method for detecting the concentration of 1,1-dichloro-1-nitroethane in air of workplaces. METHOD 1,1-dichloro-1-nitroethane in air of workplaces was collected by activated charcoal tube, absorbed using carbon disulfide and analyzed by Gas Chromatography (FID) with FFAP capillary column. RESULTS The linear rang of 1,1-dichloro-1-nitroethane in this method was 4.0-858.2 microg/ml, the linear regression formula was Y = 283X-1076, the correlation coefficient was 0.9999, the lowest detection concentration was 0.4 mg/m3 (3L sampling air), the relative standard deviation (RSD) was 1.8%-4.1%, the desorption efficiency was 88.5%-90.6%, the breakthrough volume was > 0.7 mg, the sampling efficiency was 100%, the samples could be kept at ambient temperature for at least 7 days. CONCLUSION The indicators of this method were conformed to the requirements of "Guide for establishing occupational health standards--Determination methods of air chemicals in workplace". This method could be used to detect 1,1-dichloro-1-nitroethane in air of workplaces.
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Affiliation(s)
- Jin-Ping Yang
- Tianjin Dongli District Center for Disease Control and Prevention, Tianjin, China
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Ross BM, Maxwell R, Glen I. Increased breath ethane levels in medicated patients with schizophrenia and bipolar disorder are unrelated to erythrocyte omega-3 fatty acid abundance. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:446-53. [PMID: 21115087 DOI: 10.1016/j.pnpbp.2010.11.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 11/05/2010] [Accepted: 11/22/2010] [Indexed: 01/19/2023]
Abstract
Oxidative stress has been reported to be elevated in mental illness. Preliminary evidence suggests this phenomenon can be assessed non-invasively by determining breath levels of the omega-3 polyunsaturated fatty acid (PUFA) oxidation product ethane. This study compares alkane levels in chronic, medicated, patients with schizophrenia or bipolar disorder with those in healthy controls. Both ethane and butane levels were significantly increased in patients with schizophrenia or bipolar disorder, although elevated butane levels were likely due to increased ambient gas concentrations. Ethane levels were not correlated with symptom severity or with erythrocyte omega-3 PUFA levels. Our results support the hypothesis that oxidative stress is elevated in patients with schizophrenia and bipolar disorder leading to increased breath ethane abundance. This does not appear to be caused by increased abundance of omega-3 PUFA, but rather is likely due to enhanced oxidative damage of these lipids. As such, breath hydrocarbon analysis may represent a simple, non-invasive means to monitor the metabolic processes occurring in these disorders.
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Affiliation(s)
- Brian M Ross
- Northern Ontario School of Medicine, Lakehead University, Thunder Bay, Ontario, Canada
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Chen K, Mackie JC, Kennedy EM, Dlugogorski BZ. Air pollutants formed in thermal decomposition of folpet fungicide under oxidative conditions. Environ Sci Technol 2011; 45:554-560. [PMID: 21121660 DOI: 10.1021/es102652w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This contribution studies the decomposition of folpet fungicide under oxidative conditions and compares the product species with those of captan fungicide, which is structurally related to folpet. Toxic products arising from folpet comprised carbon disulfide (highest emission factor of 4.9 mg g(-1) folpet), thiophosgene (14.4), phosgene (34.1), hydrogen cyanide (2.6), tetrachloroethylene (111), hexachloroethane (167), and benzonitrile (4.5). Owing to their related molecular structures, folpet emitted similar products to captan but at different yields, under the same experimental conditions. It appears that the availability of easily abstractable H atoms, in the structure of captan but not in that of folpet, defines the product distribution. In conjunction with the quantum chemical calculations, these experimental measurements afford an enhanced explanation of the formation pathways of hazardous decomposition products of these two structurally related fungicides.
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Affiliation(s)
- Kai Chen
- School of Engineering, The University of Newcastle, Callaghan, New South Wales, Australia
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Abstract
Although a number of gas-phase chemical mechanisms, such as CBM-IV, RADM2, and SAPRC have been successful in studying gas-phase atmospheric chemical processes, they all used different combinations of lumped organic species to describe the role of organics in gas-phase chemical processes. Photochemical Assessment Monitoring Stations (PAMS) have been in use for over a decade and yet it is not clear how the detailed organic species measured by PAMS compare to the lumped modeled species. By developing a detailed mechanism specifically for the PAMS organics and embedding this diagnostic model within a regional-scale transport and chemistry model, one can then directly compare PAMS observation with regional-scale model simulations. By means of this comparison one can perhaps better evaluate model performance. The Taiwan Air Quality Model (TAQM) was modified by adding a submodel with transport processes and chemical mechanism for interactions of the 56 species observed by PAMS. It is assumed that TAQM can simulate the overall regional-scale environment including time evolution of oxidants and radicals; these results are then used to simulate the evolution of PAMS organics with species-specific source functions, meteorological transport, and chemical interactions. Model simulations of each PAMS organic were compared with PAMS hourly surface measurements. A case study with data collected at three sites in central Taiwan showed that when meteorological simulations were comparable with observations, diurnal patterns of most organics performed well with PAMS data after emissions were corrected. It is found emissions of over half of the PAMS species require correction, some by surprisingly large factors. With such correlation, simulated time evolution of ratios of ethylbenzene/m,p-xylenes and ethane/n-butane showed similar behaviors as shown by observation data. From the results of PAMS organics diurnal variations as well as indicator ratios, one can conclude that PAMS Air Quality Model (PAMS-AQM) has been successfully developed and can be applied to the study of evolution of PAMS organics in regional and urban environments. Further, one finds that an existing VOC emissions estimation procedure heavily dependent on U.S.-data based emissions speciation factors is suspect in application in Taiwan and perhaps in other countries as well. A protocol, using PAMS-AQM for testing consistency between detailed VOC emissions and PAMS observations, has been developed and demonstrated.
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Affiliation(s)
- Sheng-Po Chen
- Institute of Atmospheric Physics and Department of Chemistry, National Central University, Taiwan
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Salau OR, Warneke T, Notholt J, Shim C, Li Q, Xiao Y. Tropospheric trace gases at Bremen measured with FTIR spectrometry. J Environ Monit 2009; 11:1529-1534. [PMID: 19657539 DOI: 10.1039/b903198g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The total column densities of acetylene (C(2)H(2)), carbon monoxide (CO), hydrogen cyanide (HCN) and ethane (C(2)H(6)) measured in Bremen (Germany, 53.107 degrees N, 8.854 degrees E) were compared with data from Mace Head/Ireland (MHD) and GEOS-Chem model simulations. The data were obtained between August 2002 and October 2006 with the ground based high resolution Fourier Transform Infra-Red (FTIR) Spectrometry, using the sun as the light source. The analysis showed good agreements between all the three data sets for the seasonal cycle of CO. Enhancements in summer 2003 and summer 2004 due to influence of biomass burning were identified in all three data sets. The high correlations between C(2)H(6) and C(2)H(2), C(2)H(2) and CO, and for C(2)H(6) and CO support the similarities in their sources and sinks. The results suggest that the background air in Bremen is mainly influenced by long-ranged transport of biomass burning products. Local pollution plays a minor role for the measurements performed in Bremen.
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Affiliation(s)
- O R Salau
- Institute of Environmental Physics, University of Bremen, Bremen, Germany.
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Abela JE, Skeldon KD, Stuart RC, Padgett MJ. Exhaled ethane concentration in patients with cancer of the upper gastrointestinal tract - a proof of concept study. Biosci Trends 2009; 3:110-114. [PMID: 20103832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
There has been growing interest in the measurement of breath ethane as an optimal non-invasive marker of oxidative stress. High concentrations of various breath alkanes including ethane have been reported in a number of malignancies. Our aim was to investigate the use of novel laser spectroscopy for rapid reporting of exhaled ethane and to determine whether breath ethane concentration is related to a diagnosis of upper gastrointestinal malignancy. Two groups of patients were recruited. Group A (n = 20) had a histo-pathological diagnosis of either esophageal or gastric malignancy. Group B (n = 10) was made up of healthy controls. Breath samples were collected from these subjects and the ethane concentration in these samples was subsequently measured to an accuracy of 0.2 parts per billion, ppb. Group A patients had a corrected exhaled breath ethane concentration of 2.3 +/- 0.8 (mean +/- SEM) ppb. Group B patients registered a mean of 3.1 +/- 0.5 ppb. There was no statistically significant difference between the two groups (p = 0.39). In conclusion, concentrations of ethane in collected breath samples were not significantly elevated in upper gastrointestinal malignancy. The laser spectroscopy system provided a reliable and rapid turnaround for breath sample analysis.
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Parameswaran KR, Rosen DI, Allen MG, Ganz AM, Risby TH. Off-axis integrated cavity output spectroscopy with a mid-infrared interband cascade laser for real-time breath ethane measurements. Appl Opt 2009; 48:B73-B79. [PMID: 19183584 DOI: 10.1364/ao.48.000b73] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cavity-enhanced tunable diode laser absorption spectroscopy is an attractive method for measuring small concentrations of gaseous species. Ethane is a breath biomarker of lipid peroxidation initiated by reactive oxygen species. A noninvasive means of quickly quantifying oxidative stress status has the potential for broad clinical application. We present a simple, compact system using off-axis integrated cavity output spectroscopy with an interband cascade laser and demonstrate its use in real-time measurements of breath ethane. We demonstrate a detection sensitivity of 0.48 ppb/Hz(1/2).
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Affiliation(s)
- Krishnan R Parameswaran
- Physical Sciences Incorporated, 20 New England Business Center, Andover, Massachusetts 01810, USA.
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Abstract
Geological and biological evidence suggests that Earth was warm during most of its early history, despite the fainter young Sun. Upper bounds on the atmospheric CO2 concentration in the Late Archean/Paleoproterozoic (2.8-2.2 Ga) from paleosol data suggest that additional greenhouse gases must have been present. Methanogenic bacteria, which were arguably extant at that time, may have contributed to a high concentration of atmospheric CH4, and previous calculations had indicated that a CH4-CO2-H2O greenhouse could have produced warm Late Archean surface temperatures while still satisfying the paleosol constraints on pCO2. Here, we revisit this conclusion. Correction of an error in the CH4 absorption coefficients, combined with the predicted early onset of climatically cooling organic haze, suggest that the amount of greenhouse warming by CH4 was more limited and that pCO2 must therefore have been 0.03 bar, at or above the upper bound of the value obtained from paleosols. Enough warming from CH4 remained in the Archean, however, to explain why Earth's climate cooled and became glacial when atmospheric O2 levels rose in the Paleoproterozoic. Our new model also shows that greenhouse warming by higher hydrocarbon gases, especially ethane (C2H6), may have helped to keep the Late Archean Earth warm.
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Affiliation(s)
- Jacob D Haqq-Misra
- Department of Meteorology, The Pennsylvania State University, University Park, PA 16802, USA.
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Noubactep C. Comment on "1,1,2,2-Tetrachloroethane reactions with OH-, Cr(II), granular iron, and a copper-iron bimetal: insights from product formation and associated carbon isotope fractionation". Environ Sci Technol 2007; 41:7947-7950. [PMID: 18075113 DOI: 10.1021/es071678i] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Bai P, Xie WJ, Liu JH. [New method of mixed gas infrared spectrum analysis based on SVM]. Guang Pu Xue Yu Guang Pu Fen Xi 2007; 27:1323-1327. [PMID: 17944405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A new method of infrared spectrum analysis based on support vector machine (SVM) for mixture gas was proposed. The kernel function in SVM was used to map the seriously overlapping absorption spectrum into high-dimensional space, and after transformation, the high-dimensional data could be processed in the original space, so the regression calibration model was established, then the regression calibration model with was applied to analyze the concentration of component gas. Meanwhile it was proved that the regression calibration model with SVM also could be used for component recognition of mixture gas. The method was applied to the analysis of different data samples. Some factors such as scan interval, range of the wavelength, kernel function and penalty coefficient C that affect the model were discussed. Experimental results show that the component concentration maximal Mean AE is 0.132%, and the component recognition accuracy is higher than 94%. The problems of overlapping absorption spectrum, using the same method for qualitative and quantitative analysis, and limit number of training sample, were solved. The method could be used in other mixture gas infrared spectrum analyses, promising theoretic and application values.
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Affiliation(s)
- Peng Bai
- School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
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Li D, Wang ZY, Xia SN. [Determination of residual epoxyethane in medical instruments by headspace capillary gas chromatography]. Zhongguo Yi Liao Qi Xie Za Zhi 2007; 31:201-2, 230. [PMID: 17672366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
OBJECTIVE To establish a method of determining the residual epoxyethane in medical instruments. METHOD An HP-5 capillary column (30 m x 0.32 mm x 0.25 microm), an FID detecter and an oven were used in the determination. The oven temperature was kept at 120 degrees C for 8 minutes, the example inlet temperature was kept at 200 degrees C, while the detecter temperature was kept at 250 degrees C. RESULT The method has a linear range between 5.1920-51.920 microg, (r = 0.997, n = 6). The average rate of recovery of the injecter is 103.3%. The average rate of recovery of the infusion devices is 81.04%. CONCLUSION The method has been proved to be convenient, sensitive and accurate. It is suitable for the determination of residual organic solvents in medical instruments.
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Affiliation(s)
- Dan Li
- Nanjing Institute for Drug Control
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Dale O, Lund T, Bergum H, Nilsen T, Aadahl P, Stenseth R. Serial samples of breath ethane can also be analyzed by gas-chromatography. Respir Med 2007; 101:679; author reply 680. [PMID: 17223332 DOI: 10.1016/j.rmed.2006.11.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 11/28/2006] [Indexed: 11/28/2022]
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Lärstad MAE, Torén K, Bake B, Olin AC. Determination of ethane, pentane and isoprene in exhaled air--effects of breath-holding, flow rate and purified air. Acta Physiol (Oxf) 2007; 189:87-98. [PMID: 17280560 DOI: 10.1111/j.1748-1716.2006.01624.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM Exhaled ethane, pentane and isoprene have been proposed as biomarkers of oxidative stress. The objectives were to explore whether ethane, pentane and isoprene are produced within the airways and to explore the effect of different sampling parameters on analyte concentrations. METHODS The flow dependency of the analyte concentrations, the concentrations in dead-space and alveolar air after breath-holding and the influence of inhaling purified air on analyte concentrations were investigated. The analytical method involved thermal desorption from sorbent tubes and gas chromatography. The studied group comprised 13 subjects with clinically stable asthma and 14 healthy controls. RESULTS Ethane concentrations decreased slightly, but significantly, at higher flow rates in subjects with asthma (P = 0.0063) but not in healthy controls. Pentane levels were increased at higher flow rates both in healthy and asthmatic subjects (P = 0.022 and 0.0063 respectively). Isoprene levels were increased at higher flow rates, but only significantly in healthy subjects (P = 0.0034). After breath-holding, no significant changes in ethane levels were observed. Pentane and isoprene levels increased significantly after 20 s of breath-holding. Inhalation of purified air before exhalation resulted in a substantial decrease in ethane levels, a moderate decrease in pentane levels and an increase in isoprene levels. CONCLUSION The major fractions of exhaled ethane, pentane and isoprene seem to be of systemic origin. There was, however, a tendency for ethane to be flow rate dependent in asthmatic subjects, although to a very limited extent, suggesting that small amounts of ethane may be formed in the airways.
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Affiliation(s)
- M A E Lärstad
- Department of Occupational and Environmental Medicine, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden.
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Pollmann J, Helmig D, Hueber J, Tanner D, Tans PP. Evaluation of solid adsorbent materials for cryogen-free trapping—gas chromatographic analysis of atmospheric C2–C6 non-methane hydrocarbons. J Chromatogr A 2006; 1134:1-15. [PMID: 17010353 DOI: 10.1016/j.chroma.2006.08.050] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 08/17/2006] [Accepted: 08/17/2006] [Indexed: 10/24/2022]
Abstract
Nine commercial solid adsorbent materials (in order of decreasing surface area: Carboxen 1000, Carbosieve S III, molecular sieve 5A, molecular sieve 4A, silica gel, Carboxen 563, activated alumina, Carbotrap and Carboxen 1016) were investigated for their ability to trap and release C2-C6 non-methane hydrocarbons (NMHCs) in atmospheric samples for subsequent thermal desorption gas chromatography-flame ionization detection analysis (GC-FID). Recovery rates for 23 NMHCs and methyl chloride (CH3Cl) were determined. A microtrap filled with the three adsorbents Carbosieve S III, Carboxen 563 and Carboxen 1016 was found to allow for the analysis of the widest range of target analytes. A detection limit of approximately 3pptC [parts per trillion (carbon)] in a 1l air sample and a linear response over a wide range of volatilities and sample volumes was determined for this configuration. Water vapor in the sample air was found to causes interference in trapping and subsequent chromatographic analysis of light NMHCs. A Peltier-cooled, regenerable water trap inserted into the sample flow path was found to mitigate these problems and to allow quantitative and reproducible results for all analytes at all tested humidity conditions.
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Affiliation(s)
- Jan Pollmann
- Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, Boulder, CO 80309, USA
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Hinrichs KU, Hayes JM, Bach W, Spivack AJ, Hmelo LR, Holm NG, Johnson CG, Sylva SP. Biological formation of ethane and propane in the deep marine subsurface. Proc Natl Acad Sci U S A 2006; 103:14684-9. [PMID: 16990430 PMCID: PMC1595412 DOI: 10.1073/pnas.0606535103] [Citation(s) in RCA: 199] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Concentrations and isotopic compositions of ethane and propane in cold, deeply buried sediments from the southeastern Pacific are best explained by microbial production of these gases in situ. Reduction of acetate to ethane provides one feasible mechanism. Propane is enriched in (13)C relative to ethane. The amount is consistent with derivation of the third C from inorganic carbon dissolved in sedimentary pore waters. At typical sedimentary conditions, the reactions yield free energy sufficient for growth. Relationships with competing processes are governed mainly by the abundance of H(2). Production of C(2) and C(3) hydrocarbons in this way provides a sink for acetate and hydrogen but upsets the general belief that hydrocarbons larger than methane derive only from thermal degradation of fossil organic material.
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Affiliation(s)
- Kai-Uwe Hinrichs
- Deutsche Forschungsgemeinschaft–Research Center Ocean Margins, Department of Geosciences, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
- Departments of Geology and Geophysics and
| | | | - Wolfgang Bach
- Deutsche Forschungsgemeinschaft–Research Center Ocean Margins, Department of Geosciences, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
- Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institute, Woods Hole, MA 02543
| | - Arthur J. Spivack
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882; and
| | - Laura R. Hmelo
- Deutsche Forschungsgemeinschaft–Research Center Ocean Margins, Department of Geosciences, University of Bremen, P.O. Box 330440, 28334 Bremen, Germany
- Departments of Geology and Geophysics and
| | - Nils G. Holm
- Department of Geology and Geochemistry, Stockholm University, 10691 Stockholm, Sweden
| | - Carl G. Johnson
- Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institute, Woods Hole, MA 02543
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Abstract
Scleroderma (systemic sclerosis) is a chronic multisystem autoimmune disease in which oxidative stress is suspected to play a role in the pathophysiology. Therefore, it was postulated that patients with scleroderma would have abnormally high breath ethane concentrations, which is a volatile product of free-radical-mediated lipid peroxidation, compared with a group of controls. There was a significant difference (p<0.05) between the mean exhaled ethane concentration of 5.27 pmol ml(-1) CO(2) (SEM=0.76) in the scleroderma patients (n=36) versus the mean exhaled concentration of 2.72 pmol ml(-1) CO(2) (SEM=0.71) in a group of healthy controls (n=21). Within the scleroderma group, those subjects taking a calcium channel blocker had lower ethane concentrations compared with patients who were not taking these drugs (p=0.05). There was a significant inverse association between lung diffusion capacity for carbon monoxide (per cent of predicted) and ethane concentration (b=-2.8, p=0.026, CI=-5.2 to -0.35). These data support the presence of increased oxidative stress among patients with scleroderma that is detected by measuring breath ethane concentrations.
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Affiliation(s)
- K A Cope
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 20705, USA.
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Abstract
We investigated whether methane, ethylene and ethane gas can be detected in gas emanating from human skin, which is called skin gas. Skin gas was collected with a homemade stainless-steel trap system, which was cooled with liquid nitrogen, and analyzed with a gas chromatograph fitted with a flame ionization detector (FID). Skin-gas samples were obtained by covering a hand for 30 min with a polyfluorovinyl bag in which pure helium gas was introduced. The bag, the trap system and GC were set up online to avoid any contamination by air. Methane, ethylene and ethane in skin gas were successfully collected at an average amount emanated for 30 min (from ten subjects) of 150 +/- 63, 20 +/- 11 and 17 +/- 8 [mean +/- SD] pg/cm2, respectively.
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Affiliation(s)
- Kazutoshi Nose
- Department of Materials Science & Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555, Japan.
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Tanner D, Helmig D, Hueber J, Goldan P. Gas chromatography system for the automated, unattended, and cryogen-free monitoring of C2 to C6 non-methane hydrocarbons in the remote troposphere. J Chromatogr A 2006; 1111:76-88. [PMID: 16497314 DOI: 10.1016/j.chroma.2006.01.100] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 01/23/2006] [Accepted: 01/24/2006] [Indexed: 11/22/2022]
Abstract
An unattended, automated, on-line, cryogen-free, remotely controlled gas chromatography (GC) system was developed and has been deployed for more than 1 year for the continuous determination of C(2) to C(6) hydrocarbons at an observatory located at 2225 m elevation, on the summit caldera of an inactive volcano on the island of Pico, Azores. The GC instrument is tailored to the measurement challenges at this remote and high altitude site. All consumable gases are prepared in situ. Total power use remains below 700 W at all times. Sample collection and analysis is performed without use of cryogen. Hydrocarbons are concentrated on a one-stage trapping/injection system consisting of a Peltier-cooled multi-bed solid adsorbent trap. Analytes are detected after thermal desorption and separation on an alumina-PLOT (porous-layer open tubular) column by flame ionization detection (FID). Sample focusing, desorption, separation and detection parameters were thoroughly investigated to ensure quantitative collection and subsequent injection onto the GC system. GC operation is controlled remotely and data are downloaded daily. Sample volumes (600 and 3000 ml) are alternated for analysis of C(2) to C(3) and C(3) to C(6) hydrocarbons, respectively. Detection limits are in the low parts per trillion by volume (pptv) range, sufficient for quantification of the compounds of interest at their central North Atlantic lower free troposphere background concentrations.
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Affiliation(s)
- David Tanner
- Institute of Arctic and Alpine Research, University of Colorado at Boulder, 80309-0450, USA
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Shoemaker JA, Bassett MV. Development of EPA method 535 for the determination of chloroacetanilide and other acetamide herbicide degradates in drinking water by solid-phase extraction and liquid chromatography/tandem mass spectrometry. J AOAC Int 2006; 89:201-9. [PMID: 16512249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
U.S. Environmental Protection Agency (EPA) Method 535 has been developed in order to provide a method for the analysis of "Alachlor ESA and other acetanilide degradation products," which are listed on EPA's 1998 Drinking Water Contaminant Candidate List. Method 535 uses solid-phase extraction with a nonporous graphitized carbon sorbent to extract the ethane sulfonic acid (ESA) and oxanilic acid degradates of propachlor, flufenacet, dimethenamid, alachlor, acetochlor, and metolachlor from finished drinking water matrixes. Separation and quantitation of the target analytes are achieved with liquid chromatography/tandem mass spectrometry. Dimethachlor ESA and butachlor ESA were chosen during the method development as the surrogate and internal standard. Drinking water samples were dechlorinated with ammonium chloride without adversely affecting the analyte recoveries. Typical mean recoveries of 92-116% in deionized water and 89-116% in ground water were observed with relative standard deviations of <5%.
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Affiliation(s)
- Jody A Shoemaker
- U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory, Cincinnati, OH 45268, USA.
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Wyse CA, Skeldon K, Hotchkiss JW, Gibson G, Yam PS, Christley RM, Preston T, Cumming DRS, Padgett M, Cooper JC, Love S. Effects of changes to the stable environment on the exhalation of ethane, carbon monoxide and hydrogen peroxide by horses with respiratory inflammation. Vet Rec 2005; 157:408-12. [PMID: 16199775 DOI: 10.1136/vr.157.14.408] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The aim of this study was to assess the effects of changes to the stable environment on exhaled markers of respiratory inflammation in six horses with clinical histories of recurrent airway obstruction. The horses were maintained for two weeks under conventional stable management (straw bedding and hay) and for two weeks on a reduced-dust regimen (paper bedding and ensiled grass), in a crossover study design. Exhaled ethane and carbon monoxide (CO) and exhaled breath condensate hydrogen peroxide (H(2)O(2)) were measured every three days under each regimen. The presence of clinical signs of airway inflammation (nasal discharge and cough) was monitored daily. The reduced-dust regimen was associated with fewer clinical signs of airway inflammation than the conventional regimen. Exhaled ethane and CO were significantly lower on the reduced-dust regimen and these markers were correlated with clinical signs of respiratory inflammation, but exhaled H(2)O(2) was not affected by the management regimen.
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Affiliation(s)
- C A Wyse
- Division of Companion Animal Sciences, Institute of Comparative Medicine, University of Glasgow Veterinary School, Bearsden, Glasgow G61 1QH, Scotland, UK
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Abstract
BACKGROUND Oxidative stress plays a role in the pathogenesis and progression of interstitial lung disease (ILD). Exhaled ethane is a product of lipid peroxidation that has been proposed as a biomarker of oxidative stress in vivo. OBJECTIVES To determine whether the exhaled ethane level is elevated in patients with ILD and to compare it with other clinical parameters. METHODS Breath samples were collected from 34 patients with ILD, including 13 with idiopathic pulmonary fibrosis (IPF), 9 patients with cryptogenic organizing pneumonia, 6 patients with collagen vascular disease-associated interstitial pneumonia, and 6 patients with pulmonary sarcoidosis. Gas samples were obtained at hospital admission and after 3 weeks. After each expired sample was concentrated using a trap-and-purge procedure, the ethane level was analyzed by gas chromatography. RESULTS Exhaled ethane levels were elevated in ILD patients (n = 34, mean +/- SD, 8.5 +/- 8.0 pmol/dL) compared with healthy volunteers (n = 16, 2.9 +/- 1.0 pmol/dL; p < 0.001). Serial measurements revealed that increase and decrease of ethane levels were largely consistent with the clinical course. Four patients with IPF who had persistently high ethane levels died or deteriorated, whereas those with ethane levels < 5.0 pmol/dL remained stable or improved. Exhaled ethane concentrations were positively correlated with levels of lactate dehydrogenase (Spearman rank correlation coefficient [rs], 0.28, p = 0.026) and C-reactive protein (rs, 0.38, p = 0.025) and were inversely correlated with Pa(O2) (rs, - 0.40, p = 0.0026). Patients showing increased uptake on (67)Ga scintigraphy demonstrated higher ethane levels (n = 19, 7.5 +/- 5.7 pmol/dL) compared with those who did not show increased uptake on scintigraphy (n = 10, 3.0 +/- 2.4 pmol/dL; p < 0.01). CONCLUSIONS Exhaled ethane is elevated in patients with ILD and is correlated with the clinical outcome, suggesting that it provides useful information about ongoing oxidative stress, and thereby disease activity and severity in ILD.
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Affiliation(s)
- Soichiro Kanoh
- Third Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
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