Abbau von N-Lost

N-Lost grenades (World War II) were investigated to determine composition, environmental impact, and degratation of their contents. The experiments suggest that the contamination of soil and groundwater is less serious than expected, due to the hydrolytic degradation of N-Lost, the minor toxic effect of N,N,N′,N′-tetra(2-chloroethyl)-piperazonium dichloride, the dimerization product of N-Lost, and its hydrolysis to triethanolamine. Gas chromatographic analysis allows for easy and sensitive detection of this warfare agent and its degradation products in water and soil.     

Abbau von Cyclosporin A durch Bodenmikroorganismen

Cyclosporin A, one of the most powerful immunosuppressants used in transplantation surgery, was shown to be degraded very slowly, within some months, by wet samples of garden soil. A standard procedure for the evaluation of cyclosporin A degradation was developed and practicized using HPLC methods. In the course of a special screening several degrading strains have been isolated from soil samples.     

Kinetik und Mechanismen beim photochemischen Abbau von Fluorphenolen

The results of a study of the photolytic degradation of mono- and difluorophenols as a function of oxidation agent and temperature are reported. The effects of the position of fluorine are discussed. Fluorinated aromatic compounds have been mineralized to CO₂, fluoride, acetate and formate by irradiation (l=254nm) over various intermediate steps. The degradation of fluorophenols apparently followed first-order kinetics. A proposed degradation pathway for the photolytic oxidation of fluorophenols is presented. A complete mineralization as generally proposed in the literature cannot be supported by our results.     

Respiration von gelösten organischen Verbindungen durch natürliche Mikroorganismen-Populationen. Ein Vergleich zwischen verschiedenen Biotopen

In 5 different biotopes (sea water, brackish water, lake, river, and sewage waters), respiration, as percent of the total uptake of 9 compounds and an amino-acid mixture, was studied. Strong variations between the biotopes could be demonstrated. Percentage respiration values varied between 11 and 57% for glucose, 20 and 37% for glucosamine, 13 and 36% for glycerol, 28 and 68% for aspartic acid, 1 and 16% for leucine, 3 and 19% for lysine, 15 and 64% for acetate, 15 and 60% for lactate, 52 and 79% for malate and between 21 and 36% for the amino-acid mixture. Despite these variations, the two amino acids leucine and lysine showed the lowest percentage and the two C 4-compounds aspartic acid and malate the highest percentage respiration in each biotope.

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Beitrag Nr. 33 aus dem Sonderforschungsbereich Nr. 95 Wechselwirkung Meer-Meeresboden, Universität Kiel.     

Untersuchungen zum Vorkommen polycyclischer Moschus-Duftstoffe in verschiedenen Umweltkompartimenten

In addition to the three compounds discussed in our first communication (UWSF 6/4, 183–189, 1994) this paper mentions another four substances from the group of the polycyclic musk flavors analysed in a number of detergents and cosmetics, in surface waters, in waste waters from municipal sewage treatment plants and in fish. These four substances are: 6-acetyl-1,1,2,3,3,5-hexamethylindane (AHMI, known for instance under the trade name Phantolide^®), 6,7-dihydro-1,1,2,3,3-pentamethyl-4 (5H)-indanone (DPMI, known for instance under the trade name Cashmeran^®), 7-acetyl-1,1,4,4-tetramethyl-6-ethyltetraline (ATTN, known for instance under the trade name Versalide^®) and 5-acetyl-1,1,2,6-tetramethyl-3-isopropylindane (ATII, known for instance under the trade name Traseolide^®). The results of these analyses show that except for ATTN, the manufacture of which was discontinued some ten years ago, these substances are considered to have an ubiquitous distribution in surface waters. This pollution evidently comes from the use of these flavors in various detergents and cosmetics, from where they enter surface waters via the waste waters from municipal sewage treatment plants. Choosing the Ruhr river as an example, the authors demonstrate that the pollution level is constant and that — due to their lipophilic nature — the compounds accumulate in fish leading to concentrations which markedly exceed those known, e.g., for nitromusk flavors in environmental samples. Two of the main contaminants are HHCB and AHTN, which have the highest concentrations both in the detergents analyzed and in environmental samples.     

Untersuchungen zum Vorkommen polycyclischer Moschus-Duftstoffe in verschiedenen Umweltkompartimenten

New flavors have been detected in GC/MS chromatograms of surface and sewage waters and fish analyzed for nitro musk compounds. This article names the polycyclic musk flavors 1,3,4,6,7,8-hexahydro-4, 6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyrane (HHCB, known for instance under the trade names: Galaxolide® and Abbalide®), 7-acetyl-1,1,3,4,4,6-hexamethyltetralin (AHTN, known for instance under the trade names: Tonalide® and Fixolide®) and 4-Acetyl-1,1-dimethyl-6-tert.butylindane (ADBI, known for instance under the trade names: Celestolide® and Crysolide®). These substances, which are widely used in the cosmetics and flavor industries, here have been established for the first time in the aquatic environment. HHCB, AHTN and ADBI — as relatively non-polar lipophilic chemicals — like organochlorine pesticides and PCBs after extraction and consecutive purification by gel permeation and silicagel adsorption chromatography are accessible to analysis by gas chromatography/mass spectrometry. Mass spectra show typical mass fragments which allow an unambigous identification and quantification. First results for surface and sewage waters and fish underline the persistence and a relatively high bioconcentration potential of these substances and suggest their ubiqitious distribution in the aquatic environment.     

Bestimmung von Spurenstoffen in Niederschlagsproben

A precipitation network consisting of 15 sites as part of the national project SANA was established to document and characterize the spatial and temporal changes of pollutants in the precipitation of East Germany. Long-term data records show a significant decrease of sulfate and calcium in the precipitation. The acidity and the nitrogen-containing ions have been remained unchanged up to now.     

Aufnahmepfade von POPs in Biota

POPs (persistent organic pollutants) associated with aquatic sediments can pose a risk to aquatic food chains, since they can be re-introduced to the food web. One major pathway is the bioaccumulation of POPs by endobenthic, sedimentingesting invertebrates (especially tubificid oligochaetes). These worms serve as food for benthivorous fish, which thereby ingest the sediment-borne chemicals and may accumulate contaminant concentrations far higher than from water exposure alone, and consequently transfer them to organisms of higher trophic levels. In order to evaluate such a potential biomagnification, a laboratory test was developed. It consisted of a two-step food chain including the sediment dwelling freshwater oligochaete Tubifex tubifex (Müller) and the three-spined stickleback (Gasterosteus aculeatus, Linné), a small teleost fish which often feeds primarily on benthic invertebrates. Artificial sediment and reconstituted water were used. To examine the influence of benthic prey on the bioaccumulation of a POP in the predator, fish were exposed to ¹⁴C-labelled hexachlorobenzene via spiked water, spiked sediment, pre-contaminated prey organisms, and to combinations of these exposure routes. Summarising the results of these experiments, it could be shown that the exposure to HCB via different routes resulted in a significantly higher accumulation in fish than an exposure to single pathways. It was concluded that the major uptake routes for fish were the overlying water and the food, whereas the contribution of spiked sediment itself was relatively small. HCB was biomagnified in the rested laboratory food chain. Therefore, concerning secondary poisoning, the environmental risk assessment of POPs like HCB should not be based on existing bioaccumulation tests alone, since they focus only on exposure via the water pathway. Instead, the influence of food and sediment as exposure routes should be considered as well, using comprehensive food chain modelling and/or laboratory studies.     

Veränderung von Biokonzentration und Wirkung vom PSM in Anwesenheit von Huminstoffen

Humic substances, in aqueous bodies primarily fulvic acids, may demonstrate an inhibitory as well as an activating influence on organisms. We present evidence with bacteria-containing algal cultures and with cultures of the nematodeCaenorhabditis elegans. Structural elements of the fulvic acids which may be responsible for such effects are not yet known. Furthermore, the presence of fulvic acids may lead to increases in bioconcentration of xenobiotics. Increase in the toxicity of xenobiotics in the presence of humic substances have also been described. We present studies applying lethal as well as sublethal toxicity endpoints.     

Aufnahme von Cyanid in Pflanzen

Cyanides are waste products from the pyrolysis of coal and are frequent soil pollutants in cities nowadays. Prussic acid (HCN) is a fast acting, highly toxic poison, but iron-complexed cyanides in soil are far less toxic. The phytotoxicity of free CN to basket willows (Salix viminalis) was determined with the tree transpiration test. The EC₁₀ for t=72 h is 0.76 mg KCN (0.3 mg CN) per liter, the EC₅₀ is 4.47 mg/l. 5 mg/l KCN are ultimately lethal. Balsam poplars (Populus trichocarpa) can survive concentrations of up to 2500 mg/l ferroferricyanide (Prussian blue), although with reduced growth. Willows survived in gas work soils with up to 452 mg/kg total CN. More CN was taken up from nutrient solution than from the soil. Complexed cyanide is probably translocated into the leaves as well. Free CN was readily eliminated from Erlenmeyers with plants growing in nutrient solution. Planting appropriate vegetation might be a suitable solution for many former gas work and mining sites.     

Aufnahme von 2,4,6-Trinitrotoluol in Pflanzen

Soil contaminations with the explosive 2,4,6-TNT are a major problem at many sites of former ammuniton plants in Germany. But only little is known about its environmental or metabolic fate in soil or plants. A field study was conducted on a former ammunition plant in Stadtallendorf/Hessen. Three areas with different TNT concentrations were planted with 8 different crops. After harvest plants were analyzed for TNT, ADNTs and DNTs. Soil contamination decreased in the rhizosphere compared to unplanted areas and there was a transfer of TNT from soil to the plants. Accumulation in plants was dependent on soil contamination and also specific for different plant parts or plant species. The contamination spectrum of TNT and derivatives was different in soil or plant tissue, respectively. After acid hydrolysis of bean roots, 2,6-DNT and 2,4-DNT could be identified in the extract.     

Umweltmonitoring von Herbiziden in aquatischen Systemen

Herbicides of the chlorinated phenoxyalkanoic acid group like 2,4-D, 2,4-DP and MCPP, belong to the most commonly used pesticides. This is also true for the Land Brandenburg. Therefore, this substance group was integrated in the current state monitoring programme for ground and surface water quality. Starting in 2001, the analysis was carried out complying with DIN 38407-20 by gas chromatography and mass spectrometric detection after enrichment with solid phase extraction and following derivatization with diazomethane-forming methyl esters. Quantifying 2,4-D considering selected ions in a surface water sample from the river Oder, a remarkable peak pattern was observed. A second peak with identical spectrum was found about 0.7 minutes earlier than the 2,4-D calibrated peak. Its intensity suggested a concentration 10–20 fold higher than the 2,4-D level. This unknown peak was identified as 2,6-D which is a structure isomer of the herbicide 2,4-D. This substance has not been described in literature or chemical substance databases known to us yet. Structure isomers have been found in other samples too. We suppose that the chlorinated phenoxyalkanoic acids chlorinated in the 6-position of the phenyl ring are formed as a technical by-product and show a higher persistance than the commonly known agents.     

Reagenzienfreie Bestimmung von Quecksilberspuren in Wasserproben

A comprehensive ecological monitoring of hazardous substances is indispensable to preserve our health and environment. Therefore, fast and inexpensive techniques for routine analysis of pollutants are essential. However, in the measuring procedure itself often toxic reagents are used producing hazardous waste. Omitting environmentally hazardous substances in the analysis procedure is an important contribution to a more sustainable and green analytical chemistry. A reagent-free method for ultra-trace (pg to ng?L^-1) mercury determination in water samples was developed and validated. An active nanogold collector integrated in a fully automated flow injection system is the core of this new method. All mercury species dissolved in the water sample are adsorbed and preconcentrated on the nano-structured gold surface of the collector. After rinsing and drying of the collector, the enriched mercury is thermally desorbed and finally measured by atomic fluorescence spectrometry. This method was optimized and validated for the determination of mercury in natural waters. The influence of various water constituents was investigated and only high contents of dissolved organic carbon (DOC) showed interferences of mercury preconcentration due to the strong complexation of mercury by DOC. This restriction can be solved by UV-irradiation, i.?e. reagent-free digestion of DOC rich samples prior to the preconcentration procedure. Mercury concentration of several natural river and sea waters and water from the discharge of a waste water treatment plant were determined with this new analytical method. Accuracy and precision of the method were demonstrated by several recovery experiments in natural water samples (recoveries: 96–102?%) and by analysis of the certified reference material BCR-579 (Mercury in Coastal Sea Water; recovery: 101?±?1?%). With a detection limit of only 80?pg?Hg?L^–1 the proposed method is highly sensitive. Furthermore the method avoids potential contamination of the sample by reagent addition and is due to the reagent-free procedure environment-friendly. Hence this work is an important contribution to sustainable environmental analysis and at the same time improves accurate routine mercury trace analysis.     

Anwendungen von Pflanzenschutzmitteln in der Landwirtschaft

A political dispute has broken out over a research project by the Federal Environmental Agency (UBA) concerning the use of plant protection agents in agriculture. Under Article 15 para. 1 No. 3 d and e of the Plant Protection Act, plant protection agents can only be authorised if their proper and appropriate use, or the consequences of such use, have no negative impacts on human or animal health or on other biological communities, especially water bodies. In specific cases the Federal Environmental Agency as the approving authority fulfils the legislative requirements with a conditional authorisation. Thus, for example, specified minimum distances to the water body must be observed according to the toxicity and exposure of the plant protection agent. The many continuing negative impacts on water bodies from the use of plant protection agents raise questions as to whether certain plant protection agents ought not to have been authorised, and whether environmental requirements were strict enough in the past or whether farmers did not comply with them to a sufficient degree. The research project described here will clarify and document possible improper practices and practical problems. Investigations will be undertaken without prior notice, as only this will enable the actual practices to be recorded. Data will be anonymous, since the project does ’not aim to ‘convict’ individual farmers. The task of the project is to collect representative data for the whole of Germany. Initial interim results will be available in 2006. This report will then be continued in a ‘Part 2’.