| 1. |
- Barrefors, Gunnar, 1963, et al.
(författare)
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Gas chromatographic separation of volatile furans from birchwood smoke
- 1996
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Ingår i: Journal of Chromatography A. ; 753, s. 151-155
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Tidskriftsartikel (refereegranskat)abstract
- Furan, 2-methylfuran, 3-methylfuran, 2,5-dimethylfuran and the five isomeric C6 alkylfurans, two C7 alkylfurans and three C6-C7 alkenylfurans were determined in birchwood smoke by adsorbent sampling, gas chromatography and mass spectrometric techniques. Retention data, mass spectral data and quantitative proportions are given. Furan and 2-methylfuran are major components. Contrary to other oxygen-containing compounds, the furans elute from the aluminium oxide column widely used for volatile C2-C8 hydrocarbons. The furans are formed mainly from glowing and smouldering combustion.
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| 2. |
- Björkqvist, Susan, 1967, et al.
(författare)
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Isoprene from expired air inside a private car
- 1997
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Ingår i: The science of the total environment. ; 207, s. 63-67
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Tidskriftsartikel (refereegranskat)abstract
- The concentration of isoprene inside a small-sized parked private car with one person was found to be of the order of 20 g/m3. Isoprene was then the major non-methane volatile hydrocarbon except in strongly traffic-polluted parking places. On driving, with intermediate fan ventilation, the isoprene levels were one order of magnitude lower. In the empty car, the concentrations were still much lower, proving that isoprene originates predominantly from expired air. Air samples were taken on triple-layer adsorbent cartridges and were analysed for volatile hydrocarbons by gas chromatography after thermal desorption. The analytical aluminium oxide column permitted simultaneous determination of a range of reported traffic-emitted hydrocarbons including the carcinogenic 1,3-butadiene and benzene.
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| 3. |
- Jonsson, Caroline, 1977, et al.
(författare)
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Kemi på Nätet : Nätet revolutionerar vetenskaplig publicering
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten refererar ett seminarium om kemi på nätet arrangerat av Kemistsamfundet i Göteborg 2011-11-24. Särskilt efterfrågad från omvärlden är fri tillgång på nätet till publikationer. Det gäller inte bara parallellpublicerade vetenskapliga artiklar utan också rapporter, avhandlingar, examensarbeten och populärvetenskap som ger önskad överblick. Det man inte får upp fritt på skärmen väljs oftast bort. En viktig fråga är också att det som nätpubliceras verkligen anpassas för läsaren på nätet. Upplägg och samarbeten som är svåra att förstå utifrån måste förklaras. Sökbarhet, länkar, titelsidors utformning och kontaktuppgifter måste prioriteras.
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| 4. |
- Kjällstrand, Jennica, 1974, et al.
(författare)
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Gas chromatographic and mass spectrometric analyses of 36 lignin-related methoxyphenols from uncontrolled combustion of wood
- 1998
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Ingår i: Journal of Chromatography A. ; 824, s. 205-210
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Tidskriftsartikel (refereegranskat)abstract
- Eighteen 4-hydroxy-3-methoxyphenyl (guaiacyl) compounds in wood smoke from spruce, and 18 4-hydroxy-3,5-dimethoxyphenyl (syringyl) analogues in birchwood smoke were analysed. Smoke samples were taken by a gas syringe from wood burning under varying but more or less choked conditions in laboratory pot experiments. Retention index data for a methylsilicone column and basic mass spectral data are given for all compounds. Retention index in combination with molecular mass and structure-specific fragment ions greatly facilitates qualitative analysis. The syringyl and guaiacyl analogues differ by 240 units in retention index and the matching structure-specific ions in their mass spectra by 30 mass units. The identified methoxyphenols differ in the structure of the sidechain, which may be lacking, an alkyl group, an alkenyl group, a carbonyl-containing group or an alcoholic moiety. The proportions between these groups of compounds varied strongly with combustion conditions whereas the proportions of phenols within them were quite specific for each group. The phenols with reactive olefinic linkages in the sidechain were present in larger proportions than reported in other studies of methoxyphenols.
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| 5. |
- Kjällstrand, Jennica, 1974, et al.
(författare)
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Methoxyphenols from burning of Scandinavian forest plant materials
- 2000
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Ingår i: Chemosphere. ; 41, s. 735-741
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Tidskriftsartikel (refereegranskat)abstract
- Semivolatile compounds in smoke from gram-scale incomplete burning of plant materials were assessed by gas chromatography and mass spectrometry. Gas syringe sampling was shown to be adequate by comparison with adsorbent sampling. Methoxyphenols as well as 1,6-anhydroglucose were released in amounts as large as 10 mg kg(-1) of dry biomass at 90% combustion efficiency. Wood, twigs, bark and needles from the conifers Norway spruce and Scots pine emitted 12 reported 2-methoxyphenols in similar proportions. Grass, heather and birchwood released the same 2-methoxyphenols but also the corresponding 2,6-dimethoxyphenols which are characteristic of angiosperms. The methoxyphenols are formed from lignin and differ in structure by the group in para position relative to the phenolic OH group. Prominent phenols were those with trans-1-propenyl and ethenyl groups in that position. Vanillin, 4-hydroxy-3-methoxybenzaldehyde, was a prominent carbonyl compound from the conifer materials.
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| 6. |
- Löfgren, Lars, 1964, et al.
(författare)
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Selective assessment of C2-C6 alkenes in air by adsorption sampling and gas chromatography
- 1991
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Ingår i: Journal of environmental analytical chemistry. ; 45, s. 39-44
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Tidskriftsartikel (refereegranskat)abstract
- A system is described for the specific determination in air of ethene, propene, the four isomeric butenes, cyclopentene and the six isomeric pentenes. The butenes, pentenes and hexenes are well separated from the commonly occurring matrix of alkanes in much higher concentrations. Field samples were taken using easily carried equipment consisting of an air pump connected to an adsorbent cartridge. An advantageous combination of triple-layer adsorbents was found to be Tenax + Carbotrap + Carbosieve S-III. In the laboratory, the hydrocarbons were thermally desorbed into a cold trap. The trap was directly linked to the aluminium oxide PLOT column which effected the alkene separations.
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| 7. |
- Olsson, Maria, 1976, et al.
(författare)
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Specific volatile hydrocarbons in smoke from oxidative pyrolysis of softwood pellets
- 2004
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Ingår i: Journal of Analytical and Applied Pyrolysis. ; 71:2, s. 847-854
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Tidskriftsartikel (refereegranskat)abstract
- Samples of smoke from laboratory burning of commercial sawdust-based softwood pellets were analysed by gas chromatography on an aluminium oxide column. Flaming burning was very efficient. Significant emitted hydrocarbons were methane, quantitatively followed by ethene and lower proportions of ethane, ethyne and propene. The even lower hydrocarbon emissions from final glowing combustion were strikingly different with ethyne and benzene as the only prominent non-methane hydrocarbons. Smouldering combustion caused much higher hydrocarbon concentrations. Prominent non-methane compounds were furan and ethene from initial smouldering, and ethane, ethene and benzene from after-flame smouldering. The large differences in the proportions of specific hydrocarbons should be considered in evaluations of emissions from residential burning of pellets, with respect to combustion technology and impact on environment and health.
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| 8. |
- Ramnäs, Olle Jerker, 1941, et al.
(författare)
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Ambient solvent hydrocarbons from the gluing of table tennis bats.
- 1995
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Ingår i: Toxicological and Environmental Chemistry. ; 47, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Solvent hydrocarbons released to air from the controversial but widely applied gluing of table tennis bats were studied during the 1993 world championships in Göteborg. Sampling on adsorbent cartridges and thermal desorption combined with gas chromatography and mass spectrometry were used for the determinations.The total concentrations recorded above the players´ gluing tables were in the range 20-100 mg/m3. The prominent solvent constituents were C6( 80%), and C8(
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| 9. |
- Ramnäs, Olle Jerker, 1941, et al.
(författare)
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Assessment by gas chromatography - mass spectrometry of hexenes emitted to air
- 1993
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Ingår i: Journal of Chromatography. ; 638, s. 65-69
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Tidskriftsartikel (refereegranskat)abstract
- Hexenes and cyclohexenes in vapours of conventional petrol were separated by gas chromatography on an aluminium oxide column. All hexenes appear in a favourable chromatographic position between hexanes and heptanes. The seventeen isomeric acyclic hexenes were identified by mass spectra and single-ion monitoring on an ion-trap mass spectrometer. The rapidly photooxidant-forming isomers with a non-terminal double bond constitute 70% of the total amount of acyclic hexenes. The proportions of isomers in petrol vapour are similar to those in urban air and in exhaust from petrol-fuelled vehicles.
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| 10. |
- Ramnäs, Olle Jerker, 1941, et al.
(författare)
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Characterization of sixty alkenes in a cat-cracked gasoline naphtha by gas chromatography
- 1994
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Ingår i: Chromatographia. ; 38, s. 222-226
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Tidskriftsartikel (refereegranskat)abstract
- The alkene-rich petrol fraction from refinery fluid catalytic cracking (FCC) has been characterized by GC and GC-MS. Quantitative proportions and retention data of 52 acyclic and 11 cyclic C5–C7 alkenes are given. Relative retentions are reported for methylsilicone and aluminium oxide stationary phases as methylene units (MU). Applications of mass spectra, single-ion GC-MS monitoring and retention data for identifications are demonstrated.
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