Determination of C2–C5 hydrocarbons in the atmosphere at low parts per 109 to high parts per 1012 levels

Rudolph, J.; Ehhalt, D. H.; Khedim, A.; Jebsen, C.

doi:10.1016/s0021-9673(00)88084-x

Cited by 39 publications

(7 citation statements)

References 17 publications

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“…There have been several series of measurements of light nonmethane hydrocarbons, including ethane, in the remote troposphere. These measurements cover seasonal cycles [Singh and Salas, 1982 by Rudolph and Jebsen [1983], Rudolph and Khedim [1985], and Rudolph et al [1981bRudolph et al [ , 1986Rudolph et al [ , 1989aRudolph et al [ , b, 1990Rudolph et al [ , 1992b. The ethane mixing ratios were determined by comparing the peak areas or heights of the sample chromatograms with those of a reference air of known ethane concentration.…”

Section: Introductionmentioning

confidence: 99%

The tropospheric distribution and budget of ethane

Rudolph¹

1995

J. Geophys. Res.

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Abstract. From about 1500 measurements of ethane in the remote troposphere the longitudinally and vertically averaged latitudinal and seasonal variability of ethane was derived. To improve the data coverage, several data sets from literature were included. There are only very few data sets available for the southern hemisphere. Nevertheless, the uncertainty of the average seasonal/latitudinal ethane profile is estimated to less than 30%. The global annually averaged ethane mixing ratio is 860 ppt. There is a strong interhemispheric gradient with an average north/south ratio of 3.5. Within the northern hemisphere there is an average gradient from the highest annual mean value of 2500 ppt around 65øN to about 600 ppt at the equator. In the southern hemisphere there is only a small gradient at low latitudes and at middle and high southern latitudes no significant gradient can be seen. In both hemispheres a significant seasonal cycle with highest mixing ratios in late winter is observed. The ethane source strength needed to balance the atmospheric budget of ethane is estimated to 15.5 Tg/yr, with most of the emissions in the northern hemisphere. An independent estimate of the sources indicate that most of the emissions are due to natural gas losses (6 Tg/yr) and biomass burning (6.4 Tg/yr). This is also compatible with the latitudinal and seasonal variation of the atmospheric ethane removal rates. However, these estimates have substantial uncertainties and it should be noted that the role of the biosphere for the atmospheric budget of ethane is presently not understood.

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Section: Introductionmentioning

confidence: 99%

The tropospheric distribution and budget of ethane

Rudolph¹

1995

J. Geophys. Res.

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“…A precolumn of Spherosil and Carbosieve at -100°C was used to enrich the hydrocarbons prior to injection. The details of the gaschromatographic analysis have been published by Rudolph et al (1981c). The hydrocarbons measured were ethane.…”

Section: Methodsmentioning

confidence: 99%

Measurements of selected C2-C5 hydrocarbons in the background troposphere: Vertical and latitudinal variations

et al. 1985

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ABSTRACT. Meridional cross sections of the concentration of light hydrocarbons are reported. They were obtained from 20. April to 10. May, 1980, during the French research flight STRATOZ 11, and cover the latitudes between 60 0 Nand 60 0 S and the altitudes between 800 mb and 200 mb. The mixing ratios of ethane, ethene, acetylene, propane, propene, n-butane, i-butane, n-pentane, and i-pentane range between 2.0 and 0.02 ppb. Globally, a decrease in concentration with increasing altitude and -in most cases -with decreasing latitude is observed. In addition the 2-dimensional concentration fields show structures of different scales. In particular, isolated maxima of high concentrations are found in the upper troposphere. They paint to fast vertical transport between the boundary layer and the upper troposphere. In the present case these maxima seem to be correlated with large scale meteorological systems, such as low pressure regions Or the Inter Tropical Convergence Zone. It is argued that the NMHC provide a set of tracers well suited to the detection of fast vertical transport.

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“…1 dm 3 to several tens of dm 3 • Glass or stainless-steel sample containers cause less contamination problems but are more expensive than plastic bags. In the past, glass vessels have been widely used for air sampling [21][22][23][24][25][26], but more recently mostly stainless-steel canisters have become more popular [1][2][3][4][5]7,14,17,[27][28][29][30][31][32][33][34][35][36][37][38][39]. Stainless-steel sample canisters are nowadays in general equipped with metal bellows valves [1][2][3][4][5]14,16,19,28,29], which avoids all polymenc seals etc.…”

Section: Whole-air Samplingmentioning

confidence: 99%

“…In addition to thorough cleanmg of the sample containers, mimmization of the active surface area is essentIal. Electropolishing of the internal surfaces and electron-beam vacuum welding of all connections are examples of technIques that help to optimize the performance of stamless-steel sample contamers [14,31]. There IS not yet a "standard" procedure for preparing, conditioning and clean-109 such containers.…”

Section: Whole-air Samplingmentioning

confidence: 99%

“…Further, the possible condensatIOn of water vapour at reduced temperatures limits the sample volume or requires the use of a drying agent. However, it should be mentIOned that preconcentration at subambient temperatures is widely used for the analysis of whole-air samples in the laboratory [1][2][3][4][5][16][17][18][19][28][29][30][31][32] or for in situ analysis [53].…”

Section: Thermal Desorptlonmentioning

confidence: 99%

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Sampling of organic volatiles in the atmosphere at moderate and low pollution levels

Rudolph¹,

Müller²,

Koppmann³

1990

Analytica Chimica Acta

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Several techntques are avatlable for measunng organic volattles m the atmosphere. For measurements at low and moderate pollUtlon levels (between several p.g m-3 and a fraction of a p.g m-3 ), the eXIstmg methods can be adopted to a broad range of different compounds. Whole-atr samphng m stamless-steel containers With metal bellows valves combmed With subsequent gas chromatograpluc separatIOn after preconcentratlon 10 the laboratory IS probably the best procedure for low and medium molecular Weight trace gases of moderate or low polanty and reasonable cherrncal stability (e.g., hydrocarbons and halocarbons). For orgamc compounds of lower volatility, adsorptlve samphng on non-polar porous orgaruc polymers (e.g, Tenax) and thermal desorptlon combmed WIth cryotrappmg and gas chromatograpluc separation of the sampled compounds IS Widely used However, there are often substantial problems due to artefact formatIOn or loss reactIOns Owmg to the generally larger sample volumes, these problems are even more pronounced for sorptlve samphng techntques combmed with sample recovery by solvent extraction. Unfortunately, the general understandmg of the vanous processes of sample degradatlon due to cherrncal reactlons of reactlve components of the atmosphere With each other or WIth the sorbent IS not yet suffiCient to allow reasonable estlmates of the extent of such mterferences Without elaborate test procedures. Keywords. Au, Samplmg procedures; Extractlon, Orgamc volatdesThe demand for accurate, reliable and sensitive techniques for the monitoring of organic trace constituents in the atmosphere has increased tremendously in the recent past. The reasons include not only a growing concern for the quality of the environment but also the realization that atmosphenc pollution is not only a local problem. At the same time, the number of different organic compounds which are emitted into the atmosphere has been rising steadily. Further, it has been recognized that several substances which had been considered harmless can pose serious hazards to the enVIronment. There is a broad range of techniques for the determination of organic compounds at trace levels wmch are sufficiently sensitive and selective. Chromatography (predominantly LC and GC) is the most widely used method and allows the identification and quantification of organic compounds in sub-nanogram amounts. With few exceptions, the analysis itself is carried out in the laboratory, which means that the sample has somehow to be transported to the laboratory. For many kinds of environmental measurements, representative and contamination-or lossfree sampling often requires substantial efforts and iD general air is one of the most difficult environmenal media for sampling. The problems are easy to understand but difficult to solve. Sample contamers for air are not only more complicated than those for solid or liquid material but also, owing to the low density of air, the volume which has to be collected for an analysis for trace components is generally larger than that for...

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Determination of C2–C5 hydrocarbons in the atmosphere at low parts per 109 to high parts per 1012 levels

Cited by 39 publications

References 17 publications

The tropospheric distribution and budget of ethane

The tropospheric distribution and budget of ethane

Measurements of selected C2-C5 hydrocarbons in the background troposphere: Vertical and latitudinal variations

Sampling of organic volatiles in the atmosphere at moderate and low pollution levels

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