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Identification of oxidized TNT metabolites in soil samples of a former ammunition plant Полный текст
1999
Bruns-Nagel, Dirk | Schmidt, Torsten C. | Drzyzga, Oliver | Löw, Eberhard v | Steinbach, Klaus
Water extracts of soil samples of the former ammunition plant “Tanne” near Clausthal-Zellerfeld, Lower Saxony, Germany, were investigated for highly polar oxidized 2,4,6-trinitrotoluene (TNT) metabolites. 0.4 to 9.0 mg/kg dry soil 2,4,6-trinitrobenzoic acid (TNBA) and 5.8 to 544 mg/kg dry soil 2-amino-4,6-dinitrobenzoic acid (2-ADNBA) were found. In addition to the oxidized metabolites, TNT, 4- and 2-aminodinitrotoluene (4- and 2-ADNT), and 2,4-dinitrotoluene (2,4-DNT) were extractable with water. Most interestingly, in one sample, 2-ADNBA represented the main contaminant.The origin of the oxidized nitroaromatics is unknown at this time. They might be generated chemically or photochemically. Furthermore, a biological synthesis seems possible.
Показать больше [+] Меньше [-]A review of biomarker compounds as source indicators and tracers for air pollution Полный текст
1999
Simoneit, Bernd R. T.
An overview of the application of organic geochemistry to the analysis of organic matter on aerosol particles is presented here. This organic matter is analyzed as solvent extractable bitumen/ lipids by gas chromatography-mass spectrometry. The organic geochemical approach assesses the origin, the environmental history and the nature of secondary products of organic matter by using the data derived from specific molecular analyses. Evaluations of production and fluxes, with cross-correlations can thus be made by the application of the same separation and analytical procedures to samples from point source emissions and the ambient atmosphere. This will be illustrated here with typical examples from the ambient atmosphere (aerosol particles) and from emissions of biomass burning (smoke).Organic matter in aerosols is derived from two major sources and is admixed depending on the geographic relief of the air shed. These sources are biogenic detritus (e.g., plant wax, microbes, etc.) and anthropogenic particle emissions (e.g., oils, soot, synthetics, etc.). Both biogenic detritus and some of the anthropogenic particle emissions contain organic materials which have unique and distinguishable compound distribution patterns (C₁₄-C₄₀). Microbial and vascular plant lipids are the dominant biogenic residues and petroleum hydrocarbons, with lesser amounts of the pyrogenic polynuclear aromatic hydrocarbons (PAH) and synthetics (e.g., chlorinated compounds), are the major anthropogenic residues.Biomass combustion is another important primary source of particles injected into the global atmosphere. It contributes many trace substances which are reactants in atmospheric chemistry and soot paniculate matter with adsorbed biomarker compounds, most of which are unknown chemical structures. The injection of natural product organic compounds into smoke occurs primarily by direct volatilization/steam stripping and by thermal alteration based on combustion temperature. Although the molecular composition of organic matter in smoke particles is highly variable, the molecular tracers are generally still source specific. Retene has been utilized as a tracer for conifer smoke in urban aerosols, but is not always detectable. Dehydroabietic acid is generally more concentrated in the atmosphere from the same emission sources. Degradation products from biopolymers (e.g., levoglucosan from cellulose) are also excellent tracers. An overview of the biomarker compositions of biomass smoke types is presented here. Defining additional tracers of thermally-altered and directly-emitted natural products in smoke aids the assessment of the organic matter type and input from biomass combustion to aerosols. The precursor to product approach of compound characterization by organic geochemistry can be applied successfully to provide tracers for studying the chemistry and dispersion of ambient aerosols and smoke plumes.
Показать больше [+] Меньше [-]Measurements of selected PCBs in open urban ambient air of Madrid (Spain) : First results Полный текст
1999
García-Alonso, Susana | Pérez-Pastor, Rosa María | Sevillano-Castaño, María Luisa
The focus of this study was to characterize the concentration levels of selected PCBs and compare them to compiled data in order to contribute to the international database. The sampling site is located in the outskirts of Madrid and can be considered an open urban area. 32 samples of air were taken from February 1998 to June 1998 by using a high volume air sampler. Glass fiber filters and polyurethane foam (PUF) were used to collect the paniculate and gas phase material, respectively.PUF plugs were Soxhlet extracted and filters were ultrasonically extracted by using pesticide-grade hexane and dichloromethane, respectively. The cleanup procedure was carried out on a florisil column with hexane and hexane/dichloromethane as elution solvents.GC/MS in a selected ion monitoring mode was used for quantification and 29 selected PCBs congeners were analyzed.
Показать больше [+] Меньше [-]Assessing the effects of international emissions reduction scenarios to combat the acidification of freshwaters in Great Britain with the First-order Acidity Balance (FAB) model and the Hull Acid Rain Model (HARM)
1999
Curtis, C.J. | Whyatt, J.D. | Metcalfe, S.E. | Allott, T.E.H. | Harriman, R.
Effect-based control strategies: what do we need in the future?
1999
Grennfelt, P.
How are results from critical load calculations reflected in lake water chemistry?
1999
Wilander, A. (SLU, Uppsala (Sweden))
Investigation of the uncertainties and assumptions in the Simple Mass Balance equation for acidity critical loads
1999
Hall, J. | Hornung, M. | Kennedy, F. | Langan, S. | Reynolds, B. | Aherne, J.
The link between the exceedance of acidity critical loads for freshwaters and biological damage: a re-interpretation
1999
Curtis, C.J. (ECRC, London (UK)) | Reynolds, B. | Allott, T.E.H. | Harriman, R.
Aluminum biogeochemistry in two Czech catchments with contrasting lithology subject to chronic acidic deposition
1999
Kram, P. | Hruska, J. (Czech Geological Survey, Prague (Czech Republic)) | Driscoll, C.T. | Johnson, C.E.
Can the division sum (Ca + K + Mg divided by Al) ratio be used as a predictive tool for estimating forest damages?
1999
Goeransson, A. (SLU, Uppsala (Sweden))