Analytik von Mineralölkohlenwasserstoffen: Die Problematik der Probenaufbereitung

For the determination of mineral oil hydrocarbons in water and soil, IR-as well as GC/FID-methods (DEV H-18, ISO/TR 11046, NEN 5733) are used. Independent of the measurement method, different clean-up procedures are prescribed in these standard methods. Aluminium oxide, silica gel and magnesium silicate (Florisil^®) are used as adsorbents. This article describes the problems of clean-up occurring in mineral oil analysis using selected substances. Tests concerning the type of adsorbent, extract medium, clean-up-technique and extract/adsorbent-ratio are presented. It will be shown that the clean-up procedure has to be counted as a significant factor of influence in the determination of mineral oil hydrocarbons. The sources of errors resulting from clean-up as well as the possibilities to avoid them are presented. An extraction solvent for soils which is simple to handle and optimally adjustable to the requirements of the clean-up procedure is presented.     

Messung und Quantifizierung von Mineralölkohlenwasserstoffen

Investigations concerning the measurement and evaluation of mineral oil hydrocarbons using Fourier-transform-infrared (FT/IR-)-spectroscopy,¹H-Nuclear magnetic resonance (¹H-NMR)-spectroscopy and Capillary gas chromatography — Flame ionisation detection (GC-FID) are presented. By means of various mineral oils and three certified reference materials (CRM) all tested methods were within a ±7%-range to the mineral oil nominal value and the 95% confidence intervals of the CRM’s, respectively. The GC-FID evaluation could be done without calibration using an relative response ratio of mineral oil to an internal standard (n-tetracontane). A¹H-NMR-method was developed for the quantitative determination of mineral oil hydrocarbons, successfully applied down to 0.2 mg/ml. Due to the determination limit achieved, the¹H-NMR-spectroscopy gain in importance as a reference method for the analysis of mineral oils.     

Bestimmung von leicht freisetzbarem Cyanid in Böden und Wässern mit der Mikrodestillation

Easy-liberatable cyanide has to be analysed if soils and waters are contaminated by cyanide. The aim of this study was to determine easy-liberatable cyanide in these environmental samples using a micro-distillation apparatus by means of a modified digestion vessel. Pure aqueous solutions of different cyanide species, five contaminated and uncontaminated soil samples and two water samples were analysed by micro-distillation according to the German standards. Recovery was determined by analysis of spiked samples. When using the modified digestion vessels, the pH of 4 which is demanded by the standard method can be adjusted. The recovery of potassium cyanide and weakly-complexed zinc-cyanide ranged from 93–101% for standards, and from 87–98% for spiked samples. In contrast, the recovery of strong iron-cyanide complexes was below 4% both for pure solutions and spiked samples. The precision of the method expressed as a relative standard deviation was 25% in cases of very low easy-liberatable cyanide contents (< 1 mg CN kg^?1) and below 12% in case of high easy-liberatable cyanide contents (> 1 mg CN kg^?1) for contaminated soils. The determination of easily-liberatable cyanide in soils and waters using micro-distillation combined with the modified digestion sample is an alternative to other distillation methods.     

Identifikation der kfz-bürtigen Schadstoffbelastung mit Hilfe der Verhältnisse der stabilen Isotope von Kohlenstoff und Schwefel

Different sources of traffic immissions (tyres, soot, oil, asphalt, plastic, paint) were analysed for stable carbon and sulphur isotope ratios. The aim of this study is to investigate whether these isotope ratios can be used to evaluate the environmental impact of traffic immitted harmful substances in roadside soils. The δ¹³C values of technical materials are between -30‰ and -18‰ (PDB). They can be distinguished by their δ¹³C value because of specific production methods. The δ¹³C value of asphalt is between -23 and -18‰, soot shows values from -27 to-22‰ Moreover, soot of different fuel have different carbon isotope ratios. Plastic, paint and oil have similar δ¹³C from -30 to -27‰ Carbon isotope ratios of automobile tyres are around -26‰ Traffic impact on the carbon isotope composition is reflected in δ¹³C values of various carbon spezies found in street sediments and road side soils. These δ¹³C values correlate to concentrations of lead and platinum. Although δ³⁴S values of technical materials are between -6 and +8‰ it was not possible to characterise samples according to their Sulphur isotopic compostion.     

Bestimmung von Redoxzonen in einem mineralölbelasteten Grundwasserleiter

Goal and Scope

The goal of this study is the investigation and the grafic presentation of the characteristic redox zonation in a mineral oil contaminated aquifer which will be formed in the plume downstream of the contamination source. Methanogenic conditions, sulfate-reduction, Fe(III)-reduction, Mn(IV)-reduction, nitrate-reduction, aerobic conditions. By that indications type and degree of microbial degradation which is the most important part in Natural Attenuation (NA) processes can be obtained easily.

Methods

Changes of the groundwater parameters Eh, O₂, NO ₃ ^? , SO₄ ^2?, Fe²⁺, Mn²⁺, HCO₃ ^?, Ca²⁺ will be measured upstream, downstream and also in the centre of the plume. The results will be presented in a sequence of special diagrams.

Results and Conclusion

When microbial degradation of hydrocarbons takes place, a microbial community will always use that electron acceptor from which it will gain a maximum of energy by the corresponding redox-reactions. This means as long as oxygen is available this will be used. After its depletion nitrate serves as electron acceptor leading via nitrite to the formation of nitrogen or ammonia. Manganese (IV) and Iron (III) species which are rather insoluble are mainly available from the soil-phase, can act as electron acceptor as next, leading to soluble Manganese (II) and Iron (II) compounds in groundwater. Finally before methanogenic conditions occur sulphate will become a suitable electron acceptor leading to the formation of hydrogen sulphide. All these processes of mineralization of the hydrocarbons will lead to the production of CO₂ and as consequence to an increase of HCO₃ ^? in groundwater changing the calcareous/carbonic acid-equilibrium. By that more soluble Ca(HCO₃)₂ is formed from insoluble CaCO₃, so the concentration from Ca²⁺ will also inerease. Thus, by the action of microorganisms, a typical redox-zonation and changes of other parameters will occur.

Recommendations and Perspective

To follow the changes in time and space of some characteristic groundwater parameters is a simple way to estimate the potential of microbial degradation in a contaminated aquifer considering Natural Attenuation (NA)-processes.     

Die Lösung von Nutzungskonflikten aufgrund flächenhafter Bodenkontaminationen mit Hilfe Geografischer Informationssysteme und Mitteln der Geostatistik

Goal and Scope

By means of Geographical Information Systems (GIS) and other geostatistical methods, the extensive heterogeneous data materials of large area soil contaminations are re-evaluated to eliminate exploitation conflicts and investment obstacles.

Methods

The mapping of relevant frame criteria generates the basis to solve the conflicts, such as types of exploitation of field areas, development plans, protected areas, flooded areas, etc. as well as their geo-referencing in the Geographical Information System. The critical examination of data age and quality as well as the geostatistical evaluation by means of semivariogram analysis and Kriging technique are essential prerequisites for the determination of areas related to utility and exceeding test values.

Results and Conclusions

As a result, one can modify the hazardous situation and can provide recommendations for an optimal elimination of hazards, mostly in the framework of scheduled measures in terms of town planning.

Outlook

On the basis of the results obtained, further exploitation or monitoring work can clearly be optimized.     

Neue Aspekte in der Behandlung von Siedlungsabflüssen

The surface runoff from urban areas is one of the most important sources of pollutants emitted into surface waters. Suspended solids which act as a transport vehicle for many anthropogenic pollutants (e.?g. heavy metals, PAH) are a key factor in this regard. The development of efficient measures of storm water runoff treatment thus requires a further differentiation of suspended solids in a fine (clay and silt) and coarse (sand and gravel) fraction. Both fractions show distinctly different characteristics in pollutant loading, transport and retention on urban surfaces and sewer systems. The primary aim of storm water runoff treatment is the reduction of the fine particles which are always highly loaded with anthropogenic pollutants. In contrast the coarse particles are almost unpolluted especially if they have a low organic share. The widespread sedimentation tanks with surface loadings between 10 and 2?m/h are very inefficient. A significant, save and lasting reduction of the emitted load of fine particles requires a considerable reduction of the surface loads. That can be achieved with the installation of lamellar settler or the utilization of the very large volumes of flood management tanks frequently present in urban areas. Filtration plants are highly efficient but there application in urban areas is limited due to their high space demands.     

HPLC-MS/MS in der Rückstandsanalytik von Pflanzenschutzmitteln

Goal and Scope

Increasing demands from the regulatory authorities of plant protection products for residue analytical methods on the one hand and the need for cost reduction by shorter development times on the other hand have led to a significant displacement of conventional methods (e.g. HPLC-UV or GC-MS) by HPLC-MS/MS with atmospheric pressure ionization (API) in residue analysis since the mid of the 1990s. This development started in the pharmaceutical industries where HPLC-MS/MS had already been used for the quantitation of drugs and their metabolites in plasma since the late 1980s.

Methods

The reason for the high acceptability of HPLC-MS/MS with electrospray ionisation (ESI) or chemical ionization at atmosheric pressure (APCI) compared with alternative methods are shown with respect to analytical quality parameters, compliance with international registration guidelines and economic reasons.

Results and Conclusion

HPLC-MS/MS is being applied for solving ca. 75% of all analytical problems occuring in modern residue analytical laboratories. This technique offers convincing advantages for the determination of plant protection products and their metabolites in various matrices. These are a reduced number of or no clean-up steps after extraction of the samples, high throughput besides high ruggedness, low limits of detection and a large linear measuring range. In addition, several analytes of various chemical classes can be determined within one chromatographic run. Due to the high selectivity there is only little need for additional confirmatory methods. For enforcement purposes HPLC-MS/MS is accepted by the European authorities since 2002. However, due to high costs for instrumentation and specially skilled personnel only few enforcement laboratories have invested into this technology, so far.

Recommendation and Perspective

The importance of HPLC-MS/MS in residue analysis will further increase, as new ionization techniques will enable the analysis of more analytes and as the investment costs will decrease in the future. However, proven conventional methods will still survive in some cases. New concepts, such as parallel HPLC-MS/MS or on-line purification of extracts by column switching which are already widely used in the pharmaceutical industry could help to further increase the throughput. However, for a sound evaluation with respect to their applicability in residue analysis there is so far too little experience.     

Photometrische Bestimmung der Zytotoxizität von Chemikalien

Two test methods are presented to assess the cytotoxicity of chemicals. On one hand the protozoonTetrahymena pyriformis and on the other the bacteriumPseudomonas aeruginosa is cultured in defined media containing the test chemicals. Test parameter is the quantity of living cells surviving exposure. The conversion of the tetrazolium salt MTT into formazan is equivalent to cell viability. A mixture of detergent and isopropanol is used to dissolve the blue formazan which is not soluble in water, prior to photometric measurement. For cetyltrimethylammonium bromide, benzyldimethyldodecylammonium chloride, dodecylbenzenesulfonic acid sodium salt, potassium dichromate, 4-toluenesulfonic acid sodium salt, and 4-nitrophenol the EC50-values (mol/l) in theTetrahymena pyriformis- (Pseudomonas aeruginosa) test system were: 10^?5,81 (10^?5,08); 10^?4,68) (10^?3,80; 10^?4,50 (10^?4,14); 10^?3,97 (10^?5,11); 10^?2,71 (10^?2,50) and 10^?4,00 (10^?3,64). — With the assays described here it is possible to measure a large number of samples by quick and simple means.     

Bewertungsmaßstäbe zur Beurteilung von Schadstoffbelastungen in Böden anhand der Bioverfügbarkeit

Until now, assessment of contaminated sites is based on variable protection goals, whereby total contents and in part mobile contents are considered. Due to interactions of pollutants in soil and bound residues, total contents do not reflect the actual risk. In contrast an investigation based on availability/bioavailability of contaminants would enable a harmonization of the protection-goal-based evaluation and a closer-to-reality risk assessment for the individual location.     

Die rolle der umweltprobenbank in der Umweltüberwachung am beispiel von chlorierten kohlenwasserstoffen in ausgewählten matrizes

For precautinary environmental protection the Environmental Specimen Bank (ESB) has been successfully established as a permanent environmental surveillance tool in Germany. The presented monitoring results on chlorinated hydrocarbons (CHC) show very clearly the effects of political decisions and can be used for the identification of pollutant sources. The CHC burden of breams (Abramis brama) from five German rivers (Elbe, Rhein, Saar, Mulde, Saale) gives an current overview of the pollution situation of different limnic ecosystems in Germany. A calculation model about the distribution of organic pollutants between different tissues offers the possibility to predict concentrations in liver and muscle of breams. Legislative emission restrictions have led to a significant decrease of dioxin levels in herring gull (Larus argentatus) eggs between 1988–1996.     

Regionale Klimatrends mit Hilfe der phänologischen Uhr, dargestellt am Beispiel Rheinland-Pfalz

Aims and Scope

Over recent decades, the climate has changed. Up to now this statement has been made predominantly for the global and/or continental area. What, however, is the situation regarding the climatic trend at the regional scale? Is it already possible to show effects of a climate change in small-scale landscape structures? These questions were addressed looking at the example of the situation in the federal state of Rhineland-Palatinate (Germany).

Methods

Phenological data of plants of the last 50 years from a total of 386 stations of the German Weather Service (DWD) were evaluated. The timing of the different plant phases, beginning of the foliation and plant senescence in autumn, flowering and the first ripening of the fruits had to be registered for different agricultural crops, wild plants, ornamental woods as well as fruit trees. The analysed data material was used to develop the threefold phenological clock (DPU).

Results

Summarising the findings of the DPU for the 15 evaluated nature districts of Rhineland-Palatinate according to individual seasons, which were defined in generic terms as spring, summer, autumn and winter, a tendency of a prematuring of the spring, a prolongation of the autumn as well as a shortening of the winter is evident. From a regional point of view, on the other hand, in individual nature districts such as the ‘Westerwald’ and the ‘Bergisch-Sauerländische Gebirge’, winter seasons are getting longer. Thus the effects of a climate change can differ considerably from region to region.

Outlook

The regionally quite different changes of the climatic situation in Rhineland-Palatinate will not remain without an effect on the ecosystems of this federal state. The currently existing biocoenosis will therefore change. The consequences for forestry, agriculture and nature conservation are of special interest in this context.     

Raumbezug in der ökosystemaren Umweltbeobachtung

Using the example of the transboundary Biosphere Reserve Rhone, experiments were performed and expounded upon with regard to the concept of ‘integrated monitoring’. The paper describes the components of a step-by-step harmonisation of data sampling and analysis procedures. Special emphasis is given to topics dealing with suitable methods for a sound selection of areas and plots to be monitored, as well as on rules for the spatial integration and generalisation of sampling results. As tools for this purpose the concept of ‘integrated monitoring’ uses the federal ‘Classification System of Ecoregions’ (Standortökologische Raumgliederung) and geostatistical methods for the spatial integration of existing monitoring programmes and sampling grids. Further, the paper outlines how to judge the development of water catchment areas using existing data from hydrological analyses and by means of an ecosystem-oriented water balance model.     

Schwermetallmonitoring mit der Standardisierten Graskultur im Untersuchungsgebiet München

For the pilotproject ?Effect Monitoring — Biomonitoring of Immission Effects in the Testing Area of Munich”, standardized grass cultures were exposed at 19 locations during 10 series for two weeks each. The grass was analyzed for the accumulation of lead, antimony arsenic, cadmium, and copper. Highest accumulation was observed with antimony near traffic situations. The comparison of the results from the different sampling points identifies motor vehicle traffic as the source of antimony. First examinations of brake linings support this conclusion. Lead is only slightly increased near traffic. Immission-caused copper contents in the grass were found near the overhead tramway cables. The accumulation detection limits for arsenic and cadmium were not exceeded at any of the measuring points.     

Nativ-basierte Grundöle für die Produktion von Kühlschmierstoffen

Aims and Scope

Compared to mineral oil products, cooling lubricants based on fatty acid esters have technological advantages. Moreover, they are more environmentally compatible and make a contribution to a sustainable economy. Nevertheless, they are rarely applied in practice, because of their comparably high price, that is based on raw-material and synthesis costs. Alternatives concerning raw-materials and synthesis pathways are considered and properties of resulting ester products are compared.

Methods

The investigations aimed at three fatty acid-2-ethyl-hexylesters that were synthesized in an enzymatic-catalytic routine based on peanut oil, suet, and waste edible fat and at esters that were conventionally produced from animal and plant fats and 2-ethyl-1-hexanol. Physical properties, fatty acid patterns, contents of free fatty acids, as well as oxidative and hydrolytic stabilities were determined. Thermolysis experiments were performed.

Results

The physical properties of the seven esters, density, viscosity, pourpoint, and flash point, were comparable and gave reason for the assumption, that the products could be used as basis oils in lubricant formulations. Hydrolysis stabilities of the esters were high and thermal stress did not point at high potential of hazardous compounds formation. Especially the enzymatic-catalytically produced esters showed deficits concerning oxidation stabilities and free fatty acid contents.

Outlook

For practice it will be necessary to define minimum qualities for raw-materials and resulting ester oils to be used as lubricant basis oils. Moreover, processes have to be developed, that yield high quality ester products from waste edible and animal fats without loosing the advantage of low-cost raw-materials by high production and refinement costs. Surely, one contribution is the further development of the energy-saving enzymtic alcoholysis for ester production.     

Kombinationswirkungen von Umweltchemikalien in der Ökotoxikologie

Ecosystems and biocoenoses are exposed to multiple mixtures of environmental pollutants, but the usual risk assessment of chemical toxicities is focussed only on the judgement of single substance toxicity. With the two biometrical models concentration-addition and independent action known from pharmacology and toxicology, a pragmatic way for the analysis of combined effects is possible using the experimental knowledge of single substance toxicity. A short introduction to the models is given and an appropriate experimental design for mixture toxicity analysis is outlined. The principal suitability of the concepts was verifed in two different bioassays (green alga; luminescent bacterium) with the analysis of binary and multiple mixture toxicities of environmental chemicals. In this paper we present the results obtained with the green algae bioassay. Congruent results from the bioluminescence inhibition assay can be found in Grimme (1998). The results obtained indicate that the toxicities of mixtures of chemicals can be studied experimentally, even at low concentrations of the individual components. Mixture toxicities were detected at low, statistically non-significantly acting concentrations of the single compounds. These results force one to take mixture toxicities into account when environmental standards are established.     

Bestimmung von Nitrodiphenylaminen und verwandten Verbindungen im Sickerwasser einer Rüstungsaltlast

Goal, Scope and Background

Nitrodiphenylamines can be found at abandoned military sites where the explosive 2,2′,4,4′,6,6′-hexanitrodiphenylamine (hexyl) or diphenylamine as a stabilizer of smokeless powder was handled. Aim of the present study is the development of HPLC methods for the analysis of contaminants which can be expected in particular under aerobic conditions at premises which are contaminated by nitrodiphenyl-amines and related compounds.

Methods

A list of 13 compounds which can be expected at these explosives factories was deduced from literature studies. HPLC methods were developed for the analytes. Water samples from the unsaturated zone of a former hexyl-producing factory were collected by suction cups and the material was analysed according to these procedures to demonstrate the practicability of the new methods and to verify the existence of the postulated compounds in the environment of the former nitration plant.

Results and Conclusion

The new HPLC methods are suitable for the exploration of sites contaminated by nitrodiphenylamines. Beside some hexyl its intermediates 1-chloro-2,4-dinitrobenzene, 2,4-dinitrodiphenylamine und 2,2′,4,4′-tetranitrodiphenylamine were identified in the leachate water.

Recommendation and Perspective

It is advisable to include at least these 4 compounds in the examination of former hexyl-producing plants. Several unknown peaks were observed in the HPLC-chromatogram. It is recommendable to perform further investigations of the unidentified compounds to compile a final list of analytes for military sites polluted by nitrodiphenylamines.     

Die Organisation der Früherkennung von Umweltproblemen im Rahmen der wissenschaftlichen Beratung der Umweltpolitik

This study is based on the theses that

1. early diagnosis is indispensable in the context of precautionary policy for the management of environmental problems which have the character of a “creeping disaster” and that
2. the public must play the active role that is adequate within a democratic society. In the context of the study, three existing advisory committees for environmental policy as well as two concepts which have not been put into effect are investigated.

In the fourth part the work of the oldest of the committees, the SRU, is examined with respect to the three most important environmental problems of the last 15 years. In part I, the concept of the Picht commission from 1972, which has never been realized in this form, was introduced. In part II, the concepts and the working method of the three existing advisory committees (SRU, WBGU, TAB) were presented. Part III deals with the critique of these committees and an alternative concept of early diagnosis which has not yet been put into effect.