ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Electronic Resource

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

Rudolph, J. ; Muller, K.P. ; Koppmann, R.

Amsterdam : Elsevier

Analytica Chimica Acta 236 (1990), S. 197-211

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ISSN: 0003-2670

Keywords: Air ; Extraction ; Organic volatiles ; Sampling procedures

Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Topics: Chemistry and Pharmacology

Type of Medium: Electronic Resource

URL: http://linkinghub.elsevier.com/retrieve/pii/S0003-2670(00)83313-9

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2

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Light hydrocarbons in the surface water of the mid-Atlantic (1992)

Plass, C. ; Koppmann, R. ; Rudolph, J.

Springer

Journal of atmospheric chemistry 15 (1992), S. 235-251

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ISSN: 1573-0662

Keywords: Hydrocarbons ; sea-water emissions ; hydrocarbon budgets

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Geosciences

Notes: Abstract During a cruise of RV Polarstern over the Atlantic in September/October 1988, C2−C4 hydrocarbons were measured in surface sea water. The ship passed through three different ocean regions divided by divergences at 8° N and 3° S. Hydrocarbon concentrations differed considerably in these regions. The highest values were obtained for ethene with mean concentrations of 246 pMol/l between 35° N and 8° N, 165 pMol/l between 8° N and 3° S, and 63 pMol/l between 3° S and 30° S. Low values were found for i- and n-butane and acetylene between 32 pMol/l and 1 pMol/l. The alkene concentrations were in general higher than the concentrations of their saturated homologs. Concentrations decreased with increasing carbon numbers. The various alkenes were well correlated with one another as were the various alkanes. Oceanic emission rates of the light hydrocarbons were calculated from their sea water concentrations using an ocean atmosphere exchange model. The averaged fluxes ranged from about 108 molec cm-2 s-1 for the alkenes and ethane to less than 107 molec cm-2 s-1 for the C4 alkanes. Acetylene emissions were below 3×106 molec cm-2 s-1. Based upon these rates budget estimates of NMHC in the ocean surface layer were made with a simple model considering production and destruction processes in the water. The emissions to the atmosphere appear to be the dominant loss process between 35° N and 8° N, whereas destruction in the water seems to be dominant in the latitude ranges 8° N-3° S and 3° S-30° S.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00115396

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3

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The distribution of light nonmethane hydrocarbons over the mid-Atlantic: Results of the Polarstern cruise ANT VII/1 (1992)

Koppmann, R. ; Bauer, R. ; Johnen, F. J. ; [et al.]

Springer

Journal of atmospheric chemistry 15 (1992), S. 215-234

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ISSN: 1573-0662

Keywords: Hydrocarbons ; carbon monoxide ; marine atmosphere ; Atlantic ; hydrocarbon budgets

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Geosciences

Notes: Abstract During the cruise ANT VII/1 (September/October 1988) of the German research vessel Polarstern the latitudinal distributions of several nonmethane hydrocarbons were measured over the Atlantic between 45°N and 30°S by in-situ gas chromatography. On the average, the highest mixing ratios of ethane, propane, i- and n-butane, ethene and acetylene were observed in the Northern Hemisphere around 40° N and just north of the intertropical convergence zone, respectively. South of the equator, a bulge in the mixing ratios of ethane and acetylene was observed indicating aged biomass burning emissions. This observation coincided with enhanced tropospheric ozone found in this region at this season. On the average ethane and acetylene mixing ratios were around 500 and 100 ppt, respectively, whereas the levels of the other NMHC were in the range of some ppt up to 100 ppt. compared with the results of the cruise ANT V/5 (March/April, 1987), the ethane mixing ratios in September/October proved to be a factor of 3 lower in the Northern Hemisphere and a factor of 2 higher in the Southern Hemisphere, probably due to seasonal effects. Possible causes are the higher OH radical concentrations in summer, which result in a faster removal of ethane or stronger emission from biomass burning which also peaks in the dry season. The relative pattern of the hydrocarbons just north of the ITCZ was very similar for both measurement series. In this region, the NMHC were advected by long-range transport from the continent, whereas generally the ocean itself acts as a major NMHC source. This is supported by the results of a balance calculation between oceanic emissions and atmospheric removal rates.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00115395

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4

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Measurements of Carbon Monoxide and Nonmethane Hydrocarbons During POPCORN (1998)

Koppmann, R. ; Plass-Dülmer, C. ; Ramacher, B. ; [et al.]

Springer

Journal of atmospheric chemistry 31 (1998), S. 53-72

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ISSN: 1573-0662

Keywords: carbon monoxide ; nonmethane hydrocarbons ; photochemistry ; air mass characterization

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Geosciences

Notes: Abstract During the field campaign POPCORN (Photo oxidant formation by plant emitted compounds and OH radicals in North-eastern Germany) in Pennewitt (Mecklenburg-Vorpommern, Germany) in August 1994, carbon monoxide and nonmethane hydrocarbons were measured over a large maize field by in-situ gas chromatography. Throughout the campaign CO and NMHC showed, even for a remote rural area, unexpectedly low mixing ratios. Except a few episodes, CO mixing ratios were around 120 ppb. Ethane was the only hydrocarbon showing mixing ratios exceeding 1 ppb. The mixing ratios of all other NMHC ranged between several hundred ppt and the lower limit of detection which was between 20 and 5 ppt depending on the compound. During three frontal passages CO and NMHC mixing ratios increased significantly, while between August 13 and 16, 1994, polar air masses were encountered with CO and NMHC mixing ratios dropping to values which are typical for North Atlantic background air. During this period average CO mixing ratios were 85 ppb and ethane as the most abundant hydrocarbon decreased to 650 ppt. The large-scale meteorological situation is reflected in an unusual frequency distribution of CO. The distribution shows three maxima which can be assigned to the periods of the frontal passages, to the observation of polar air masses and the rest of the campaign. Two-day backward trajectories were calculated in order to obtain information about the origin of the air masses transported to the site. The observed NMHC and CO data can be attributed to the origin of the air masses and the air mass trajectories. NMHC and CO mixing ratios were well correlated indicating that these compounds originated from similar mostly anthropogenic sources. An exception was isoprene which showed no correlation with CO. With values below 100 ppt the mixing ratio of isoprene, which is emitted by terrestrial vegetation, was also unexpectedly low during the first half of the campaign although the maximum temperatures were around 35°C.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1023/A:1005996527025

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5

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Peroxyacetyl Nitrate (PAN) Measurements During the POPCORN Campaign (1998)

Schrimpf, W. ; Linaerts, K. ; Müller, K. P. ; [et al.]

Springer

Journal of atmospheric chemistry 31 (1998), S. 139-159

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ISSN: 1573-0662

Keywords: peroxyacetyl nitrate ; rural measurements ; odd oxygen radicals ; photochemistry

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Geosciences

Notes: Abstract During the POPCORN campaign between 3 and 24 August 1994 we measured peroxyacetyl nitrate (PAN) in a rural area of Mecklenburg-Vorpommern (North-Eastern Germany) above a corn field. A total of about 5000 PAN measurements were carried out within the three weeks of the campaign. Measured PAN mixing ratios ranged from below the detection limit of 10 ppt up to an afternoon maximum of 1 ppb. The mean value of all data was 140 ppt. The daily mean PAN mixing ratios were typically in the range of 50 to 250 ppt, but during a clean air episode PAN mixing ratios of well below 40 ppt were observed. The characteristic relative diurnal variation of the PAN mixing ratios with a late night/early morning minimum and an afternoon maximum persisted during these episodes. The daily averages of the PAN mixing ratios showed clear episodic variations which coincided with the duration of typical synoptic episodes of two to six days duration. Based on the measurements of the various parameters determining the PAN formation and destruction rates, the local budget for PAN was calculated. During daytime the calculated net photochemical formation rate of PAN was nearly always significantly higher than the observed change of the PAN concentration. This demonstrates that substantial amounts of PAN (often in the range of several hundred ppt/h) were exported from the corn field. The resulting removal of NOx to some extent effects the budget of nitrogen oxides (NOx), but the export of odd oxygen radicals in the form of PAN during daytime often amounted up to 30–50% of the OH-radical formation by ozone photolysis. Thus the importance of PAN as reservoir and transport medium for odd oxygen radicals can be very substantial and may have a significant impact on the budget and distribution of odd oxygen radicals.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1023/A:1006004031055

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6

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Field study of the emissions of methyl chloride and other halocarbons from biomass burning in Western Africa (1995)

Rudolph, J. ; Khedim, A. ; Koppmann, R. ; [et al.]

Springer

Journal of atmospheric chemistry 22 (1995), S. 67-80

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ISSN: 1573-0662

Keywords: biomass burning ; halocarbons ; hydrocarbons ; methylchloride ; emission ratios

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology , Geosciences

Notes: Abstract A field study of trace gas emissions from biomass burning in Equatorial Africa gave methyl chloride emission ratios of 4.3×10−5±0.8×10−5 mol CH3Cl/mol CO2. Based on the global emission rates for CO2 from biomass burning we estimate a range of 226−904×109 g/y as global emission rate with a best estimate of 515×109 g/y. This is somewhat lower than a previous estimate which has been based on laboratory studies. Nevertheless, our emission rate estimates correspond to 10–40% of the global turnover of methyl chloride and thus support the importance of biomass burning as methyl chloride source. The emission ratios for other halocarbons (CH2Cl2, CHCl3, CCl4, CH3CCl3, C2HCl3, C2Cl4, F-113) are lower. In general there seems to be a substantial decrease with increasing complexity of the compounds and number of halogen atoms. For dichloromethane biomass burning still contributes significantly to the total global budget and in the Southern Hemisphere biomass burning is probably the most important source for atmospheric dichloromethane. For the global budgets of other halocarbons biomass burning is of very limited relevance.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00708182

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7

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Measurements of dissolved nonmethane hydrocarbons in sea water (1991)

Plass, C. ; Koppmann, R. ; Rudolph, J.

Springer

Fresenius' Zeitschrift für analytische Chemie 339 (1991), S. 746-749

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ISSN: 1618-2650

Source: Springer Online Journal Archives 1860-2000

Topics: Chemistry and Pharmacology

Notes: Summary An automated stripping technique for the measurement of dissolved hydrocarbons in sea water is presented together with some results obtained during a ship cruise from Europe to Brazil. The sea water concentrations of NMHC were determined in a three step process: degassing, preconcentration, and gas chromatographic analysis. In a stripping chamber the dissolved gases were purged from sea water with helium. The stripped hydrocarbons were cryogenically concentrated, and after thermal desorption they were injected into the gas chromatograph. The light fraction (C2–C4) was separated on a packed and the heavy fraction (C5–C10) on a capillary column. All valves were microprocessor controlled in order to achieve an automated process. For the C2–C4 hydrocarbons the stripping efficiencies exceeded 90% except for acetylene (80%), the lower limit of detection was 1 to 4.5 pmol hydrocarbon per liter of sea water and the accuracy of the method was better than 25%, depending on the individual hydrocarbons. Typical oceanic concentrations were in the 10 and 100 pmol/l range. Alkenes were generally more abundant than the corresponding alkanes and within the homologous series the concentrations decreased with increasing number of carbon atoms.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00321737

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