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Liu Y, Hou X, Li X, Liu J, Jiang G. Simultaneous determination of 19 bromophenols by gas chromatography-mass spectrometry (GC-MS) after derivatization. Talanta 2024; 274:126015. [PMID: 38581850 DOI: 10.1016/j.talanta.2024.126015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 03/26/2024] [Accepted: 03/29/2024] [Indexed: 04/08/2024]
Abstract
Bromophenols (BPs) are a class of ubiquitous emerging halogenated pollutants. Their 19 congeners are problematically separated and detected. This work described the separation and detection of 19 BP congeners by gas chromatography-mass spectrometry (GC-MS). Investigations into the derivatization of bromophenols were carried out using two silylation reagents (N,O-bis(trimethylsilyl)trifluoroacetamide and N-methyl-N-(trimethylsily)trifluoroacetamide), two alkylation reagents (methyl iodide and trimethylsilyldiazomethane) and acetic anhydride prior to GC-MS analysis. Optimal chromatographic separation, sensitivity, and linearity were achieved after BP derivatization using acetic anhydride, featuring the equipment detection limits of 0.39-1.26 pg and correlation coefficients of 0.9948-0.9999 (linear range: 0.5-250 ng mL-1) for all 19 BP congeners. Furthermore, the simultaneous determination of 19 bromophenols and 19 bromoanisoles, common environmental transformation products of BPs, is also demonstrated. The improved analytical performance on GC-MS after derivatization would benefit investigations on the environmental origins, behaviors and fates of BPs and their environmental metabolites.
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Affiliation(s)
- Yanwei Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xingwang Hou
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xiaoying Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Jiyan Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China.
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, China
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2
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Ravanbodshirazi S, Boutfol T, Safaridehkohneh N, Finkler M, Mohammadi-Kambs M, Ott A. The Nature of the Spark Is a Pivotal Element in the Design of a Miller-Urey Experiment. Life (Basel) 2023; 13:2201. [PMID: 38004341 PMCID: PMC10672138 DOI: 10.3390/life13112201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 10/30/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Miller and Urey applied electric sparks to a reducive mixture of CH4, NH3, and water to obtain a complex organic mixture including biomolecules. In this study, we examined the impact of temperature, initial pressure, ammonia concentration, and the spark generator on the chemical profile of a Miller-Urey-type prebiotic broth. We analyzed the broth composition using Gas Chromatography combined with Mass Spectroscopy (GC/MS). The results point towards strong compositional changes with the nature of the spark. Ammonia exhibited catalytic properties even with non-nitrogen-containing compounds. A more elevated temperature led to a higher variety of substances. We conclude that to reproduce such a broth as well as possible, all the studied parameters need to be tightly controlled, the most difficult and important being spark generation.
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Affiliation(s)
| | | | | | | | | | - Albrecht Ott
- Biological Experimental Physics, Center for Biophysics, Faculity of Natural Sciences and Technology, Saarland University, Campus B2 1, 66123 Saarbrücken, Germany; (S.R.)
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3
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Tiusanen A, Ruiz-Jimenez J, Hartonen K, Wiedmer SK. Analytical methodologies for oxidized organic compounds in the atmosphere. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:1263-1287. [PMID: 37491999 DOI: 10.1039/d3em00163f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Oxidized compounds in the atmosphere can occur as emitted primary compounds or as secondary products when volatile emitted precursors react with various oxidants. Due to the presence of polar functional groups, their vapor pressures decrease, and they condense onto small particles. Thereby, they have an effect on climate change by the formation of clouds and scattering solar radiation. The particles and oxidized compounds themselves can cause serious health problems when inhaled. Therefore, it is of utmost importance to study oxidized compounds in the atmosphere. Much ongoing research is focused on the discovery of new oxidized substances and on the evaluation of their sources and factors influencing their formation. Monitoring biogenic and anthropogenic primary oxidized compounds or secondary oxidized products in chamber experiments or field campaigns is common. New discoveries have been reported, including various oxidized compounds and a new group of compounds called highly oxidized organic molecules (HOMs). Analytics of HOMs are mainly focused on chromatography and high-resolution mass spectrometry employing chemical ionization for identifying and quantifying compounds at low concentrations. Oxidized compounds can also be monitored by spectrophotometric methods in which the determinations of total amounts are based on functional groups. This review highlights recent findings on oxidized organic compounds in the atmosphere and analytical methodologies used for their detection and quantification. The discussion includes gas and liquid chromatographic methods, sampling, extraction, concentration, and derivatization procedures involved, as well as mass spectrometric and spectrophotometric methods.
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Affiliation(s)
- Aleksi Tiusanen
- Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
| | - Jose Ruiz-Jimenez
- Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
- Institute for Atmospheric and Earth System Research, Chemistry, Faculty of Science, P.O. Box 55, FI-00014 University of Helsinki, Finland
| | - Kari Hartonen
- Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
- Institute for Atmospheric and Earth System Research, Chemistry, Faculty of Science, P.O. Box 55, FI-00014 University of Helsinki, Finland
| | - Susanne K Wiedmer
- Department of Chemistry, P.O. Box 55, FI-00014 University of Helsinki, Finland.
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4
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Noppawan P, Bainier C, Lanot A, McQueen-Mason S, Supanchaiyamat N, Attard TM, Hunt AJ. Effect of harvest time on the compositional changes in essential oils, cannabinoids, and waxes of hemp ( Cannabis sativa L.). ROYAL SOCIETY OPEN SCIENCE 2022; 9:211699. [PMID: 35719880 PMCID: PMC9198500 DOI: 10.1098/rsos.211699] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 04/27/2022] [Indexed: 05/03/2023]
Abstract
Demand for cannabinoid is growing, with the global market expected to reach $9.69 billion by 2025. Understanding how chemical composition changes in hemp at different harvest times is crucial to maximizing this industrial crop value. Important compositional changes in three different compound classes (essential oils, cannabinoids, and lipids) from inflorescences (tops), leaves, and stems of hemp (Cannabis sativa L., Finola variety) at different harvesting stages have been investigated. Over 85% of the total extracts from the tops were cannabinoids, while leaves demonstrated the greatest quantities of wax ester and sterols. Essential oil and cannabinoid increased in tops until full flowering (third harvest), reaching 2030 µg g-1 and 39 475 µg g-1, respectively. Cannabinoids decreased at seed maturity (final harvest) to 26 969 µg g-1. This demonstrates the importance of early harvesting to maximize cannabidiol (CBD), which is highly sought after for its therapeutic and pharmacological properties. A total of 21 161 µg g-1 of CBD was extracted from the tops at full flowering (third harvest); however, a significant increase (63%) in the banned psychoactive tetrahydrocannabinol (THC) was observed from budding (157 µg g-1 of biomass) to the full flowering (9873 µg g-1 of biomass). Harvesting the tops after budding is preferable due to the high CBD content and low amounts of THC.
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Affiliation(s)
- Pakin Noppawan
- Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Camille Bainier
- Department of Chemistry, Green Chemistry Centre of Excellence, University of York, Wentworth Way, York YO10 5DD, UK
| | - Alexandra Lanot
- Department of Biology, Centre for Novel Agricultural Products, University of York, Wentworth Way, York YO10 5DD, UK
| | - Simon McQueen-Mason
- Department of Biology, Centre for Novel Agricultural Products, University of York, Wentworth Way, York YO10 5DD, UK
| | - Nontipa Supanchaiyamat
- Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Thomas M. Attard
- RX Extraction Ltd., Unit 10, Rowen Trade Estate, Neville Road, Bradford BD4 8TQ, UK
| | - Andrew J. Hunt
- Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
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5
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Jaramillo EA, Ferreira Santos MS, Noell AC, Mora MF. Capillary electrophoresis method for analysis of inorganic and organic anions related to habitability and the search for life. Electrophoresis 2021; 42:1956-1964. [PMID: 34287988 DOI: 10.1002/elps.202100134] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/07/2021] [Accepted: 07/09/2021] [Indexed: 11/08/2022]
Abstract
In situ missions of exploration require analytical methods that are capable of detecting a wide range of molecular targets in complex matrices without a priori assumptions of sample composition. Furthermore, these methods should minimize the number of reagents needed and any sample preparation steps. We have developed a method for the detection of metabolically relevant inorganic and organic anions that is suitable for implementation on in situ spaceflight missions. Using 55 mM acetic acid, 50 mM triethylamine, and 5% glycerol, more than 21 relevant anions are separated in less than 20 min. The method is robust to sample ionic strength, tolerating high concentrations of background salts (up to 900 mM NaCl and 300 mM MgSO4 ). This is an important feature for future missions to ocean worlds. The method was validated using a culture of Escherichia coli and with high salinity natural samples collected from Mono Lake, California.
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Affiliation(s)
| | | | - Aaron C Noell
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Maria F Mora
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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6
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Bikkina S, Kawamura K, Sakamoto Y, Hirokawa J. Low molecular weight dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls as ozonolysis products of isoprene: Implication for the gaseous-phase formation of secondary organic aerosols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 769:144472. [PMID: 33477044 DOI: 10.1016/j.scitotenv.2020.144472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 12/06/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Oxidation of isoprene, a major biogenic volatile organic compound emitted from forest canopies, is a potential source of oxalic acid; the dominant species in organic aerosols. We evaluated here ozonolysis of isoprene in dry darkness as a source of oxalic (C2), malonic (C3) and succinic (C4) acids. We found that oxalic acid and methylglyoxal are dominant products within 10 min of reaction followed by glyoxylic, malonic or succinic acids. Interestingly, molecular distributions of oxidation products from early reactions (9-29 min) were characterized by the predominance of methylglyoxal followed by C2, which became dominant after 30 min. The isoprene-derived secondary organic aerosols (SOAs) showed chemical evolution with reaction time towards the molecular characteristics of dicarboxylic acids similar to those of ambient aerosols (C2>C3≥C4). The carbon-based relative abundances of methylglyoxal decreased steadily (40%→30%), while those of C2 increased with reaction time (15%→25%), but no such variations persisted for glyoxal (6-10%). This finding means that methylglyoxal is more important intermediate of oxalic acid than glyoxal. In contrast, smaller variability and lower concentrations of pyruvic and glyoxylic acids than other intermediates indicate that oxalic acid formation under dry conditions follows a different pathway than in aqueous-phase heterogeneous chemistry usually invoked for cloud/fog/atmospheric waters. Here, we propose new reaction schemes for high levels of methylglyoxal and oxalic acid via gas-phase chemical reactions with ozone and OH radicals to better interpret the ambient SOA composition. Furthermore, the relative abundances of C2 exhibit small variability from 1 to 8 h, suggesting its stable character towards the oxidation by hydroxyl radicals.
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Affiliation(s)
- Srinivas Bikkina
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, Aichi, Japan
| | - Kimitaka Kawamura
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, Aichi, Japan; Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.
| | - Yosuke Sakamoto
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan; Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Jun Hirokawa
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
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7
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Zhang Y, Gao B, Valdiviez L, Zhu C, Gallagher T, Whiteson K, Fiehn O. Comparing Stable Isotope Enrichment by Gas Chromatography with Time-of-Flight, Quadrupole Time-of-Flight, and Quadrupole Mass Spectrometry. Anal Chem 2021; 93:2174-2182. [PMID: 33434014 PMCID: PMC10782559 DOI: 10.1021/acs.analchem.0c04013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Stable isotope tracers are applied for in vivo and in vitro studies to reveal the activity of enzymes and intracellular metabolic pathways. Most often, such tracers are used with gas chromatography coupled to mass spectrometry (GC-MS) owing to its ease of operation and reproducible mass spectral databases. Differences in isotope tracer performance of the classic GC-quadrupole MS instrument and newer time-of-flight instruments are not well studied. Here, we used three commercially available instruments for the analysis of identical samples from a stable isotope labeling study that used [U-13C6] d-glucose to investigate the metabolism of the bacterium Rothia mucilaginosa with respect to 29 amino acids and hydroxyl acids involved in primary metabolism. The prokaryote R. mucilaginosa belongs to the family of Micrococcaceae and is present and metabolically active in the airways and sputum of cystic fibrosis patients. Overall, all three GC-MS instruments (low-resolution GC-SQ MS, low-resolution GC-TOF MS, and high-resolution GC-QTOF MS) can be used to perform stable isotope tracing studies for glycolytic intermediates, tricarboxylic acid (TCA) metabolites, and amino acids, yielding similar biological results, with high-resolution GC-QTOF MS offering additional capabilities to identify the chemical structures of unknown compounds that might show significant isotope enrichments in biological studies.
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Affiliation(s)
- Ying Zhang
- West Coast Metabolomics Center, University of California, Davis, 95616, CA, USA
- Department of Chemistry, University of California, Davis, 95616, CA, USA
| | - Bei Gao
- Department of Medicine, University of California, San Diego, San Diego, 92093, CA, USA
- School of Marine Sciences, Nanjing University of Information Science and Technology, Nanjing, 210044, China
| | - Luis Valdiviez
- West Coast Metabolomics Center, University of California, Davis, 95616, CA, USA
| | - Chao Zhu
- College of Medicine & Nursing, Dezhou University, De Zhou, Shandong, 253023, China
| | - Tara Gallagher
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - Katrine Whiteson
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - Oliver Fiehn
- West Coast Metabolomics Center, University of California, Davis, 95616, CA, USA
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8
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Kristensen M, Christensen P, Christensen JH. Optimization and validation of a derivatization method with boron trifluoride in ethanol for analysis of aromatic carboxylic acids in water. J Chromatogr A 2019; 1601:21-26. [PMID: 31078279 DOI: 10.1016/j.chroma.2019.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 10/26/2022]
Abstract
Gas-chromatography (GC) analysis of carboxylic acids is limited by the high polarity and low volatility of most of these compounds. Boron trifluoride (BF3) mediated alkylation reactions is one of the most commonly used derivatization methods for making carboxylic acids GC compatible. A semi-automated BF3·EtOH (ethanol) derivatization method was optimized for comprehensive two-dimensional gas chromatography high-resolution mass spectrometry (GC × GC-HR MS) analysis of carboxylic acids in solid phase extraction (SPE) extracts of oil polluted water. The optimal derivatization method were found to be with addition of 300 μL BF3·EtOH per 200 μL sample and reaction at 75 °C for 24 h. Derivatives of eight selected acids (aliphatic, mono- and di-aromatic) were stable over 12 h with relative standard deviations (RSDs) of 2.0-10.7 %, the derivatization method was repeatable (RSDs of 3.2-17.2 %), detection limits (DL) and limit of detections (LODs) was in the range of DL = 0.53-1.63 ppb and LOD = 0.19-2.51 ppb for pure acid standards, and DL = 0.18-3.41 ppb and LOD = 0.28-5.46 ppb for matrix matched acid standards. Finally, the method was validated on the acidic fraction of a mixed anion-exchange SPE of oil polluted water. Thousands of degradation products from parent alkylated polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons, such as aliphatic acids and mono-, di- and tri- aromatic acids were analyzed by the applied method and compound groups were tentatively identified.
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Affiliation(s)
- Mette Kristensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.
| | - Peter Christensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Jan H Christensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
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9
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Makoś P, Przyjazny A, Boczkaj G. Methods of assaying volatile oxygenated organic compounds in effluent samples by gas chromatography—A review. J Chromatogr A 2019; 1592:143-160. [DOI: 10.1016/j.chroma.2019.01.045] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/12/2019] [Accepted: 01/17/2019] [Indexed: 12/13/2022]
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10
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Balla D, Voutsa D, Samara C. Study of polar organic compounds in airborne particulate matter of a coastal urban city. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:12191-12205. [PMID: 28887799 DOI: 10.1007/s11356-017-9993-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
Two classes of polar organic compounds, dicarboxylic acids (DCAs) and sugars/sugar anhydrides (S/SAs), were measured in airborne particulate matter in the area of Thessaloniki, northern Greece. The target compounds were measured simultaneously in two particle fractions PM10 and PM2.5 during cold and warm periods by employing extraction in an ultrasonic bath with a mixture of MeOH/DCM (1:2 v/v), derivatization with BSTFA-TMCS and GC-MS for analysis. At both fractions, phthalic was the predominant carboxylic acid during cold season and a-ketoglutaric acid in warm season, followed by maleic and malic. Levoglucosan was the dominant sugar anhydride during the cold and arabitol during the warm season. In total, the distribution of DCAs seemed to favor the PM2.5 particle fraction, probably due to anthropogenic emissions and photochemical formation. The relative contribution of DCAs to PM2.5 fraction was 0.9-3.2% in cold and 0.9-7.0% in warm period. Regarding S/SAs, levoglucosan was also predominantly distributed in fine particles, with relative contribution to this fraction 0.1-6.3% in cold and <0.65% in warm season, suggesting impact of biomass burning emissions. In contrast, arabitol, fructose, and glucose were mainly found in coarse fraction, possibly due to their biogenic origin. Negative correlation of target compounds with temperature and total solar radiation suggested the contribution of seasonal dependant local sources. Positive relationship with NO and NO2 oxidants and relative humidity showed secondary formation of polar compounds or enhanced gas-to-particle conversion.
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Affiliation(s)
- Dimitra Balla
- Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University, 541 24, Thessaloniki, Greece.
| | - Dimitra Voutsa
- Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University, 541 24, Thessaloniki, Greece.
| | - Constantini Samara
- Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University, 541 24, Thessaloniki, Greece
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11
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Rousová J, Chintapalli MR, Lindahl A, Casey J, Kubátová A. Simultaneous determination of trace concentrations of aldehydes and carboxylic acids in particulate matter. J Chromatogr A 2018; 1544:49-61. [DOI: 10.1016/j.chroma.2018.02.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 02/06/2018] [Accepted: 02/14/2018] [Indexed: 01/26/2023]
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12
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Fiori J, Amadesi E, Fanelli F, Tropeano CV, Rugolo M, Gotti R. Cellular and mitochondrial determination of low molecular mass organic acids by LC-MS/MS. J Pharm Biomed Anal 2017; 150:33-38. [PMID: 29216582 DOI: 10.1016/j.jpba.2017.11.071] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/24/2017] [Accepted: 11/28/2017] [Indexed: 12/23/2022]
Abstract
A selective and sensitive method for the determination of low molecular mass organic acids (LMMOAs) in cell and mitochondrial extracts is presented. The analytical method consists in the separation by reversed phase liquid chromatography and detection with tandem mass spectrometry (LC-MS/MS) of the LMMOAs like malic, succinic, formic and citric acids. These acids are among the cellular intermediates of the tricarboxylic acid cycle (TCA), thus their quantitation can provide essential information about the catabolic and anabolic processes occurring in cells under physiological and pathological conditions. The analytical method was fully validated in terms of linearity, detection and quantification limits, recovery and precision. Detection limits (LOD) for malic, succinic and fumaric acids were in the range of 1-10nM, while 20nM was obtained for citric acid. Analytical recovery in cell and mitochondrial extracts was found between 88 and 105% (CV% ≤7.1) and matrix effect was estimated to be less than 108%. The LC-MS/MS method applied to the quantification of TCA cycle metabolites revealed a different distribution of the four acids in cells and mitochondria, and it could be used to monitoring metabolic alterations associated with TCA cycle and oxidative phosphorylation dysfunctions.
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Affiliation(s)
- Jessica Fiori
- Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy.
| | - Elisa Amadesi
- Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy
| | - Flaminia Fanelli
- Endocrinology Unit and Center for Applied Biomedical Research, Department of Medical and Surgical Sciences, University of Bologna - S. Orsola-Malpighi Hospital, Italy
| | | | - Michela Rugolo
- Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy
| | - Roberto Gotti
- Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126, Bologna, Italy
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13
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Optimization of an ultrasound-assisted derivatization for GC/MS analysis of oxygenated organic species in atmospheric aerosol. Anal Bioanal Chem 2017; 409:4279-4291. [DOI: 10.1007/s00216-017-0379-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/06/2017] [Accepted: 04/24/2017] [Indexed: 11/26/2022]
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14
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Zhu H, Janusson E, Luo J, Piers J, Islam F, McGarvey GB, Oliver AG, Granot O, McIndoe JS. Phenol-selective mass spectrometric analysis of jet fuel. Analyst 2017; 142:3278-3284. [DOI: 10.1039/c7an00908a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A bromobenzyl charged tag selectively reacts with key contaminants in jet fuel to provide charged ethers that are readily detectable by ESI-MS.
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Affiliation(s)
- Haoxuan Zhu
- Department of Chemistry
- University of Victoria
- Canada
| | | | - Jingwei Luo
- Department of Chemistry
- University of Victoria
- Canada
| | - James Piers
- Department of Chemistry
- University of Victoria
- Canada
| | | | | | - Allen G. Oliver
- Molecular Structure Facility
- Department of Chemistry and Biochemistry
- University of Notre Dame
- Notre Dame
- USA
| | - Ori Granot
- Department of Chemistry
- University of Victoria
- Canada
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15
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Xiong Y, Zhou J, Schauer JJ, Yu W, Hu Y. Seasonal and spatial differences in source contributions to PM 2.5 in Wuhan, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 577:S0048-9697(16)32338-5. [PMID: 28029452 DOI: 10.1016/j.scitotenv.2016.10.150] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/19/2016] [Accepted: 10/19/2016] [Indexed: 06/06/2023]
Abstract
Fine particle (PM2.5) samples were collected in 2011 and 2012 simultaneously at three sites in Wuhan in an industrial area (ID), downtown Wuhan (DT), and the Wuhan botanical gardens (BG). The annual average concentration of PM2.5 was highest in the industrial area at 180μgm-3 and lowest in the botanical gardens, with an average of 93μgm-3. The average downtown PM2.5 concentration was 113μgm-3. All sites had concentrations well above the World Health Organization (WHO) guidelines and the Chinese air quality standard. The concentration of major constituents of PM2.5 varied seasonally across all sites; specifically, sulfate, nitrate, and organic carbon varied most strongly during spring, followed by summer and fall. Organic carbon varied the most across sites for all seasons, which is attributable to large differences in local source emissions. The major primary sources contributing to OC were vehicle emissions (38.1±8.3%), coal combustion (7.0±6.2%), meat cooking (3.0±1.6%), and biomass burning (3.0±1.0%). All these sources had large seasonal variations across the three sites. Biomass burning had the largest impact at BG, mobile sources had the largest impact at DT, and coal combustion had the largest impact at ID. Mineral dust was a major contributor to PM2.5 (average 16.8±9.6μgm-3) and had very homogenous concentrations across the sites during springtime due to regional dust storms, but had much higher concentration at ID during the summer and fall. The results demonstrate the need for both regional and local air pollution control strategies to reduce air pollution in Wuhan. This research contributes to the field of particulate matter studies by providing information about seasonal and regional fluctuations in PM2.5 in large urban areas, which helps advance understanding of the sources responsible for urban haze.
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Affiliation(s)
- Ying Xiong
- School of Resources and Environmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China
| | - Jiabin Zhou
- School of Resources and Environmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
| | - James J Schauer
- Environmental Chemistry and Technology Program, University of Wisconsin-Madison, 660 North Park Street, Madison, WI 53706, USA.
| | - Wenyang Yu
- School of Resources and Environmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China
| | - Yan Hu
- School of Resources and Environmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China
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16
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Flores RM, Doskey PV. Evaluation of multistep derivatization methods for identification and quantification of oxygenated species in organic aerosol. J Chromatogr A 2015; 1418:1-11. [DOI: 10.1016/j.chroma.2015.09.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 08/24/2015] [Accepted: 09/15/2015] [Indexed: 11/29/2022]
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17
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Lai C, Liu Y, Ma J, Ma Q, Chu B, He H. Heterogeneous Kinetics of cis-Pinonic Acid with Hydroxyl Radical under Different Environmental Conditions. J Phys Chem A 2015; 119:6583-93. [DOI: 10.1021/acs.jpca.5b01321] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chengyue Lai
- State Key Joint Laboratory
of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yongchun Liu
- State Key Joint Laboratory
of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Jinzhu Ma
- State Key Joint Laboratory
of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Qingxin Ma
- State Key Joint Laboratory
of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Biwu Chu
- State Key Joint Laboratory
of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Hong He
- State Key Joint Laboratory
of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
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18
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Lai C, Liu Y, Ma J, Ma Q, He H. Laboratory study on OH-initiated degradation kinetics of dehydroabietic acid. Phys Chem Chem Phys 2015; 17:10953-62. [DOI: 10.1039/c5cp00268k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The degradation kinetics of dehydroabietic acid by OH radicals were investigated under various environmental conditions.
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Affiliation(s)
- Chengyue Lai
- State Key Joint Laboratory of Environment Simulation and Pollution Control
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing
- China
| | - Yongchun Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing
- China
| | - Jinzhu Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing
- China
| | - Qingxin Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing
- China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing
- China
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19
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Tan B, Lu Z, Dong S, Zhao G, Kuo MS. Derivatization of the tricarboxylic acid intermediates with O-benzylhydroxylamine for liquid chromatography-tandem mass spectrometry detection. Anal Biochem 2014; 465:134-47. [PMID: 25102203 DOI: 10.1016/j.ab.2014.07.027] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/24/2014] [Accepted: 07/25/2014] [Indexed: 02/04/2023]
Abstract
The tricarboxylic acid (TCA) cycle is an interface among glycolysis, lipid metabolism, and amino acid metabolism. Increasing interest in cancer metabolism has created a demand for rapid and sensitive methods for quantifying the TCA cycle intermediates and related organic acids. We have developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify the TCA cycle intermediates in a 96-well format after O-benzylhydroxylamine (O-BHA) derivatization under aqueous conditions. This method was validated for quantitation of all common TCA cycle intermediates with good sensitivity, including α-ketoglutarate, malate, fumarate, succinate, 2-hydroxyglutarate, citrate, oxaloacetate, pyruvate, isocitrate, and lactate using a 8-min run time in cancer cells and tissues. The method was used to detect and quantify changes in metabolite levels in cancer cells and tumor tissues treated with a pharmacological inhibitor of nicotinamide phosphoribosyl transferase (NAMPT). This method is rapid, sensitive, and reproducible, and it can be used to assess metabolic changes in cancer cells and tumor samples.
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Affiliation(s)
- Bo Tan
- Tailored Therapeutics, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA.
| | - Zhaohai Lu
- Cancer Research, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - Sucai Dong
- Cancer Research, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - Genshi Zhao
- Cancer Research, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - Ming-Shang Kuo
- Tailored Therapeutics, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA
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20
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GC/MS analysis of water-soluble organics in atmospheric aerosol: optimization of a solvent extraction procedure for simultaneous analysis of carboxylic acids and sugars. Anal Bioanal Chem 2012; 405:1095-104. [DOI: 10.1007/s00216-012-6592-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 11/16/2012] [Accepted: 11/16/2012] [Indexed: 10/27/2022]
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21
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Hyder M, Jönsson JÅ. Hollow-fiber liquid phase microextraction for lignin pyrolysis acids in aerosol samples and gas chromatography–mass spectrometry analysis. J Chromatogr A 2012; 1249:48-53. [DOI: 10.1016/j.chroma.2012.06.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 06/11/2012] [Accepted: 06/14/2012] [Indexed: 11/26/2022]
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22
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Jurado-Sánchez B, Ballesteros E, Gallego M. Determination of carboxylic acids in water by gas chromatography–mass spectrometry after continuous extraction and derivatisation. Talanta 2012; 93:224-32. [DOI: 10.1016/j.talanta.2012.02.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 02/06/2012] [Accepted: 02/10/2012] [Indexed: 10/28/2022]
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23
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Hyder M, Genberg J, Jönsson JÅ. Application of hollow fiber liquid phase microextraction for pinic acid and pinonic acid analysis from organic aerosols. Anal Chim Acta 2012; 713:79-85. [DOI: 10.1016/j.aca.2011.11.046] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 11/22/2011] [Accepted: 11/24/2011] [Indexed: 11/28/2022]
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24
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Kitanovski Z, Grgić I, Veber M. Characterization of carboxylic acids in atmospheric aerosols using hydrophilic interaction liquid chromatography tandem mass spectrometry. J Chromatogr A 2011; 1218:4417-25. [DOI: 10.1016/j.chroma.2011.05.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 02/28/2011] [Accepted: 05/09/2011] [Indexed: 10/18/2022]
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25
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Št’ávová J, Beránek J, Nelson EP, Diep BA, Kubátová A. Limits of detection for the determination of mono- and dicarboxylic acids using gas and liquid chromatographic methods coupled with mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:1429-38. [PMID: 21185238 PMCID: PMC3090519 DOI: 10.1016/j.jchromb.2010.11.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 10/01/2010] [Accepted: 11/24/2010] [Indexed: 11/24/2022]
Abstract
The chromatographic separation and instrumental limits of detection (LODs) were obtained for a broad range of C(1)-C(18) monocarboxylic (MCAs) and C(2)-C(14) dicarboxylic acids (DCAs) employing either chemical derivatization followed by gas chromatography-mass spectrometry and flame ionization detection (GC-MS/FID) or direct analysis with liquid chromatography high resolution MS and tandem MS (LC-MS). Suitability, efficiency and stability of reaction products for several derivatization agents used for esterification (BF(3)/butanol), and trimethysilylation, including trimethylsilyl-N-N-dimethylcarbamate (TMSDMC) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) were evaluated. The lowest limits of detection for the majority of compounds below 10 pg (with the exception of acetic acid) were obtained for derivatization with BF(3)/butanol followed by GC-MS in the total ion current (TIC) mode. Further improvements were achieved when applying either selected ion monitoring (SIM), which decreased the LODs to 1-4 pg or a combination of SIM and TIC (SITI) (2-5 pg). GC-FID provided LODs comparable to those obtained by GC-MS TIC. Both trimethylsilylation (followed by GC-MS) and direct LC-MS/MS analysis yielded LODs of 5-40 pg for most of the acids. For volatile acids the LODs were higher, e.g., 25 and 590 ng for TMSDMC and BSTFA derivatized formic acid, respectively, whereas the LC-MS methods did not allow for the analysis of formic acid at all.
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Affiliation(s)
- Jana Št’ávová
- University of North Dakota, Department of Chemistry, 151 Cornell Street Stop 9024, Grand Forks, ND 58202, USA
| | - Josef Beránek
- University of North Dakota, Department of Chemistry, 151 Cornell Street Stop 9024, Grand Forks, ND 58202, USA
| | - Eric P. Nelson
- University of North Dakota, Department of Chemistry, 151 Cornell Street Stop 9024, Grand Forks, ND 58202, USA
| | - Bonnie A. Diep
- University of North Dakota, Department of Chemistry, 151 Cornell Street Stop 9024, Grand Forks, ND 58202, USA
| | - Alena Kubátová
- University of North Dakota, Department of Chemistry, 151 Cornell Street Stop 9024, Grand Forks, ND 58202, USA
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26
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Optimisation of pressurised liquid extraction for the ultra-trace quantification of 20 priority substances from the European Water Framework Directive in atmospheric particles by GC–MS and LC–FLD–MS/MS. Anal Chim Acta 2011; 693:47-53. [DOI: 10.1016/j.aca.2011.03.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2010] [Revised: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 11/22/2022]
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27
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Pietrogrande MC, Bacco D. GC–MS analysis of water-soluble organics in atmospheric aerosol: Response surface methodology for optimizing silyl-derivatization for simultaneous analysis of carboxylic acids and sugars. Anal Chim Acta 2011; 689:257-64. [DOI: 10.1016/j.aca.2011.01.047] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 01/18/2011] [Accepted: 01/23/2011] [Indexed: 10/18/2022]
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28
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Luo LH, Seo JW, Oh BR, Seo PS, Heo SY, Hong WK, Kim DH, Kim CH. Stimulation of reductive glycerol metabolism by overexpression of an aldehyde dehydrogenase in a recombinant Klebsiella pneumoniae strain defective in the oxidative pathway. J Ind Microbiol Biotechnol 2010; 38:991-9. [PMID: 20862513 DOI: 10.1007/s10295-010-0872-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 09/08/2010] [Indexed: 11/30/2022]
Abstract
Previously, we constructed a glycerol oxidative pathway-deficient mutant strain of Klebsiella pneumoniae by inactivation of glycerol dehydrogenase (dhaD) to eliminate by-product synthesis during production of 1,3-propanediol (1,3-PD) from glycerol. Although by-product formation was successfully blocked in the resultant strain, the yield of 1,3-PD was not enhanced, probably because dhaD disruption resulted in insufficient regeneration of the cofactor NADH essential for the activity of 1,3-PD oxidoreductase (DhaT). To improve cofactor regeneration, in the present study we overexpressed an NAD(+)-dependent aldehyde dehydrogenase in the recombinant strain. To this end, an aldehyde dehydrogenase AldHk homologous to E. coli AldH but with NAD(+)-dependent propionaldehyde dehydrogenase activity was identified in K. pneumoniae. Functional analysis revealed that the substrate specificity of AldHk embraced various aldehydes including propionaldehyde, and that NAD(+) was preferred over NADP(+) as a cofactor. Overexpression of AldHk in the glycerol oxidative pathway-deficient mutant AK/pVOTHk resulted in a 3.6-fold increase (0.57 g l(-1) to 2.07 g l(-1)) in the production of 3-hydroxypropionic acid (3-HP), and a 1.1-fold enhancement (8.43 g l(-1) to 9.65 g l(-1)) of 1,3-PD synthesis, when glycerol was provided as the carbon source, compared to the levels synthesized by the control strain (AK/pVOT). Batch fermentation using AK/pVOTHk showed a significant increase (to 70%, w/w) in conversion of glycerol to the reductive metabolites, 1,3-PD and 3-HP, with no production of by-products except acetate.
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Affiliation(s)
- Lian Hua Luo
- Microbe-Based Fusion Technology Research Center, Jeonbuk Branch Institute, KRIBB, Jeongeup, Jeonbuk, 580-185, South Korea
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29
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Pietrogrande MC, Bacco D, Marchetti N, Mercuriali M, Zanghirati G. 2D autocovariance function for comprehensive analysis of two-way GC-MS data matrix: application to environmental samples. Talanta 2010; 83:1225-32. [PMID: 21215857 DOI: 10.1016/j.talanta.2010.07.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 07/19/2010] [Accepted: 07/24/2010] [Indexed: 10/19/2022]
Abstract
This paper describes a signal processing method for comprehensive analysis of the large data set generated by hyphenated GC-MS technique. It is based on the study of the 2D autocovariance function (2D-EACVF) computed on the raw GC-MS data matrix, extending the procedure previously developed for 1D to 2D signals. It appears specifically promising for GC-MS investigation, in particular to single out ordered patterns in complex data: such patterns can be simply identified by visual inspection from deterministic peaks in the 2D-EACVF plot. A case of order along the retention time axis (x=t(R)) is represented by a horizontal sequence of peaks, located at the same interdistance Δt(R)=b(x), e.g., b(x) is the CH(2) retention time increment between subsequent terms of an homologous series. The order along the fragment mass axis (y=m/z) contains information on analyte fragmentation patterns. Deterministic peaks appear in the 2D-EACVF plot at Δm/z values corresponding to the most abundant ion fragments - dominating fragments in MS spectrum - or to ions generated by repetitive loss of the same ion fragment, i.e., Δm/z=14 amu produced by the [CH(2)]() group loss in n-alkanes. Method applicability was tested by processing GC-MS data of organic extracts of atmospheric aerosol samples: attention is focused on identifying and characterizing homologous series of organics, i.e., n-alkanes and n-alkanoic acids, since they are considered molecular tracers able to track the origin and fate of different organics in the environment.
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