Quantitative elimination of Flavokavines A and B from Kava Kava (<Emphasis Type="Italic">Piper methysticum</Emphasis> G. Forst) by isoelectric focused adsorptive bubble separation

Adsorptive bubble separation, though still rarely used, is a suitable method for enrichment of surface-active macromolecules such as enzymes and proteins. There is a lack of investigations with small molecules, which can also be separated from complex mixtures by this method. In this work, an aqueous extract of Kava Kava (Piper methysticum G. Forst) was used as a model system. Enrichment of undesirable Flavokavine A (7) and Flavokavine B (8) in the foam was influenced by the pH value, the amount of saponin as surface active substance, and the flow rate of the foam-forming gas. Efficiency was highest with diluted samples at pH 6.5. Under these conditions, transfer of Kavapyrone (1–6) to the foam was negligible.     

A comparative study of polychlorinated alkanes as standards for the determination of C10-C13 polychlorinated paraffines in fish samples

Fish samples of different origins have been analysed with short column gas chromatography-electron capture negative ion/mass spectrometry (SCGC/ECNI-MS). The influence of standards composed from different polychlorinated alkanes on the quantification of short chain polychlorinated paraffines (CP) was studied. Concentration values varied very differently with the response of the standards depending on their chlorination degree. The results show, that technical CP products should not be used as standard in most cases, because the composition of polychlorinated alkanes in fish is different from sample to sample.     

Visual interpretation of satellite imagery for monitoring floods in Bangladesh

This article presents the methods and results of visual interpretation of NOAA AVHRR imagery for mapping flood areas in Bangladesh. Color composites of channels 1 and 2 for 18 August 1987 and 10, 15, and 24 September 1988 were interpreted visually for delineating flood boundaries. On such imagery flood areas appear in dark tones and are separated from land (light tones) owing to the absorption of near infrared by water and its reflectance by land and non-waterbodies. Visual interpretation was aided by the use of ground information, such as physiographic and river maps, previous flood maps, newspaper reports, and other published and unpublished documents on the 1987 and 1988 floods. Interpreted flood areas on selected images ranged from 31% to 43% of the total area of Bangladesh. Visual interpretation overestimated flood areas by 5%–10%, compared to the digitally analyzed data. The main advantage of visual analysis lies in the cost effectiveness of AVHRR photographic products, which make them more accessible than the digital image analysis of computer-compatible tapes.     

Analysis of short chain chlorinated paraffins in sediment samples from the Czech Republic by short-column GC/ECNI-MS

Top layer sediment samples from the Czech Republic were analyzed to obtain the preliminary information about contamination of the region by chlorinated paraffins. Sediment samples from three locations with different industrial discharges were taken over the period of 2 years. The analysis was performed by short-column gas chromatography-electron capture negative ion mass spectrometry (SCGC/ECNI-MS). Short chain chlorinated paraffin sediment concentrations varied between 24.00 and 45.78 ng g(-1) (dry weight, d.w.) in the Kosetice area, 16.30-180.75 ng g(-1) (dry weight) in the Zlín area and 4.58-21.57 ng g(-1) dry weight in the Beroun area. Highly chlorinated undecanes prevailed in the samples. On the basis of these results, more detailed studies should be conducted to determine the magnitude and extent of chlorinated paraffin contamination in these regions.     

Reaktion von Pendimethalin in Lösung bei UV-bestrahlung

Pendimethalin (I) decomposed in hexane, methanol and aqueous methanol upon irradiation with UV-light (λ > 290 nm) to form “polar” products. The main products formed are the dinitroaniline (II) and the isomers mono-nitroanilines (III). Kinetic studies indicate that the photodegradation of pendimethalin is strongly dependent of solvent and concentration.     

Understanding of groundwater salinity using statistical modeling in a small tropical island,East Malaysia

This paper presents an understanding of groundwater salinity by identification of effective factors using chemometric methods (cluster analysis and multiple linear regressions) in Manukan Island, Sabah. Local groundwater and environmental properties were used to explore the effective factors of groundwater salinity. Cluster analysis showed salinity and chloride illustrated the highest similarities. Electrical conductivity and total dissolved solids were also grouped in the same cluster. Seawater is the only chloride source in groundwater of Manukan Island demonstrated an indication of seawater mixing in freshwater. It is an effect of upward movement of the seawater by pumping activities. Precipitation and evapotranspiration (environmental condition) with hydraulic heads were clustered together to show that they also influence salinity concentration in groundwater. Multiple linear regressions showed descending order of the factors from chloride (the largest contribution) to evapotranspiration (the smallest contribution) and illustrated the contribution to groundwater salinity in Manukan Island. The integrated results using chemometric methods have provided a way to identify the effective factors on groundwater salinity. This similar approach and resulting equation can be applied in other small tropical islands with alike hydrogeological condition and limited information available for a better understanding of its groundwater salinity.     

Analysis of airborne pollen grains in Bilecik, Turkey

In this study, pollen grains in the atmosphere of Bilecik were studied for a continuous period of 2 years (2005 and 2006) by using Durham sampler. During this period, pollen grains belonging to 46 taxa were recorded, 26 of which belonged to arboreal plants and 20 to non-arboreal. Of total 14,269 pollen grains determined in Bilecik atmosphere, 6,675 were recorded in 2005 and 7,594 were in 2006. From these, 75.74% were arboreal, 21.80% were non-arboreal and 2.47% unidentifiable. Pinus sp., Poaceae, Cupressaceae, Platanus sp., Quercus sp., Salix sp., Ailanthus sp., Fagus sp., Urticaceae, Chenopodiaceae/Amaranthaceae were the main pollen producers in the atmosphere of Bilecik, respectively. Pollen concentrations reached their highest levels in May. Atmospheric pollen concentrations in February, March, September, October and November were less than those in other months.     

Toxaphen in der Umwelt

Toxaphene is a mixture of more than 200 polychlorinated C₁₀-terpenes. Due to its persistence and long-range transport, it is distributed all over the world. Many of the components are very stable under environmental conditions, while others are easily degraded by UV-light or microorganisms. The main conversion pathway is reductive dechlorination and dehydrochlorination; oxidative degradation possibly occurs only after previous dechlorination. Accumulation especially in the aquatic environment has led in many cases to high residue levels in fish, marine mammals, and sea birds of the northern hemispere. Toxaphene is mutagenic in the Ames test and of high toxicity for fish, but few data are available on the toxicity of single components or their mode of action.