| 1. |
- Björkqvist, Susan, 1967, et al.
(författare)
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Hydrocarbons in biogas from household solid waste
- 1998
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Ingår i: Environmental Technology (United Kingdom). - 1479-487X .- 0959-3330. ; 19:6, s. 639-642
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Tidskriftsartikel (refereegranskat)abstract
- The components of biogas from source-separated domestic waste were studied for the first major Swedish plant (Sobacken, Boras) in operation. Methane, carbon dioxide and C-6-C-11 hydrocarbons were determined by gas chromatographic methods. The content of methane was found to be just over 70% (v/v). The major polluting hydrocarbon in the biogas was p-cymene. It may be formed by rearrangement and dehydrogenation of limonene and other monoterpenes in food waste.
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| 2. |
- 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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| 3. |
- 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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| 4. |
- Barrefors, Gunnar, 1963, et al.
(författare)
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Exposure to volatile hydrocarbons in commuter trains and diesel buses
- 1996
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Ingår i: Environmental Technology. ; 17, s. 643-647
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Tidskriftsartikel (refereegranskat)abstract
- Percentage proportions of 25 C2-C7 hydrocarbons were determined inside both diesel buses and commuter trains in regular traffic. The hydrocarbons originate predominantly from petrol-fuelled vehicles. The total proportion of unburnt petrol components (mainly alkanes and arenes) was considerably larger than the proportion of combustion-formed components (mainly ethene, ethyne and propene). The approximate relative proportions 1 :1 :0.4 :0.1 were observed for the genotoxic species benzene, ethene, propene, and 1,3-butadiene. Isoprene from expired air of the passengers constituted a prominent fraction, particularly in the buses. Samples were taken on triple-layer adsorbent cartridges and were analyzed in the laboratory by thermal desorption and gas chromatography on an aluminium oxide column. Passenger exposure to traffic-emitted volatile hydrocarbons was 2-3 times higher for diesel bus commuters than for train commuters. The presence of road vehicles nearer to the buses explains this difference. Additional pollution in buses from their diesel exhaust strengthens commuter trains as a superior alternative with respect to the exposure of the passengers to hazardous air pollutants.
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| 5. |
- 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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| 6. |
- Barrefors, Gunnar, 1963, et al.
(författare)
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Assessment by gas chromatography and gas chromatography - mass spectrometry of volatile hydrocarbons from biomass burning
- 1995
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Ingår i: Journal of Chromatography A. ; 710, s. 71-77
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Tidskriftsartikel (refereegranskat)abstract
- Well over thirty combustion-formed non-methane hydrocarbons were determined from uncontrolled burning of biogenic materials. Results are given for straw, conifer twigs, newsprint and hardwood. Samples were taken on triple-layer adsorption cartridges. After thermal desorption, the hydrocarbons were separated by gas chromatography on an aluminium oxide column. Samples were also taken with a gas syringe and analyzed after gas injection. The hydrocarbon compositions were found to be remarkably similar for different kinds of biomass. Among 21 recorded alkenes and alkadienes, ethene was predominant, and the next most prominent species were propene and 1,3-butadiene. The large proportions of ethyne and the carcinogenic benzene increased further with increasing combustion efficiency.
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| 7. |
- Barrefors, Gunnar, 1963, et al.
(författare)
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Volatile hydrocarbons from domestic wood burning
- 1995
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Ingår i: Chemosphere. ; 30, s. 1551-1556
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Tidskriftsartikel (refereegranskat)abstract
- The quantitative proportions of 16 alkenes, 5 alkadienes, 5 alkynes and several alkanes and arenes were determined in emissions from wood burning in a wood-stove and in small-scale model experiments. Samples were taken on triple-layer adsorption cartridges, and gas chromatographic separations were performed on an aluminium oxide column.Ethene, ethyne and benzene were major components, especially from efficient flame combustion. The proportions of C3-C7 alkenes were markedly higher for smouldering. The carcinogenic compounds benzene and 1,3-butadiene constituted roughly 10-20% and 1-2% by weight of total non-methane hydrocarbons. Similar results were obtained for hardwood and softwood.
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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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