Raman mapping of coal halos induced by uranium mineral radiation.

Raman mapping microspectroscopy was used as an advantageous high spatial resolution method for detailed assessment of the structure of radiation-induced halos in bituminous coal (Upper Paleozoic) with numerous inclusions of uraninite and coffinite. The uranium content in inclusions in the samples studied ranged from 40 to 50 wt%. Raman structural parameters such as full width at half maximum, the positions of the D-band and G-band peaks and their area ratios were calculated, and these correlated well with vitrinite reflectance. Using linear profiles across the entire halos, changes in the degree of radiolytic alteration of coal matter caused by ionising radiation resulting from the decay of uranium and its daughter products, were described. Using micro-ATR-FTIR, oxidative radiolytic alteration of coal was identified in halos, with oxidisation to alcohols, ketones and carboxyl groups, which were then converted to COO- ions bound to the cations present, including UO22+. From our data, we conclude that the conversion of the original coal to a type of anthracite occurred during the process of CH and CC cleavage, dehydroaromatisation of naphthenic rings and oxidation resulting in the transformation of aliphatic structures into aromatic clusters. Generally, radiolytic alteration increased the structural organisation of coal. Monte Carlo simulations of the observed radiation alteration by the ionising energy loss and non-ionising energy loss were performed.

Chemical characterization of mountain forest soils: impact of long-term atmospheric deposition loadings (Czech-Polish-German border region).

The composition of lipids in soil offers clues to soil degradation processes due their persistency and selectivity in soil, and close relation to long-term processes in the ecosystem, thanks to their role in cell membranes of organisms. Organic solvent-extractable compounds were recovered from soils collected at two sites differing in the degree of forest damage. Gas chromatography/mass spectroscopy and Fourier transform infrared spectroscopy were applied in order to characterize solvent-extractable lipids. Raman spectroscopy was also applied as it provides distinct advantages for determining the structural order of carbonaceous materials. The organic matter measurement techniques were combined with an established simultaneous multi-element measurement technique. Variations in individual soil horizons from the sites were reflected in the crystallinity of epicuticular waxes, presence of long-chain aliphatic hydrocarbons, concentrations of n-alkanes, saturated and unsaturated fatty acids, dicarboxylic acids, and in the content of aromatic structures, hydroxyl, ester, and carboxylic acid groups. The results are explained by differently transformed organic matter. The concentrations of elements in the soils were also affected by atmospheric depositions, including higher accumulations of arsenic and antimony, and lower contents of natural nutrients. These data have potential to be used as sensitive biogenic indicators of ecosystem damage by long-term atmospheric depositions.

Characterization of Eocene fossil resin from Moravia, Czech Republic: Insights into macromolecular structure.

Two pieces of studlovite - Eocene amber from Studlov (Southeast Moravia, Czech Republic) were investigated. To arrive at a more detailed description, attenuated total reflection Fourier transform infrared spectroscopy, Raman spectroscopy, pyrolysis-gas chromatography/mass spectrometry, and gas chromatography-mass spectrometry were used. Both studlovite samples revealed signs of the same plant source, with higher polymerisation and a higher degree of maturation of the fossilized matter. Despite their close spectral resemblance, they differed in their detailed chemical composition, and in structure. Layering of one of the pieces studied showed how the resin was built and what impact the process had on the chemical composition of the amber. Characterization of the organic matter was completed with an analysis of trace elements in amber samples using scanning electron microscope combined with elemental distribution analysis (SEM/EDAX). The results demonstrated the paleoenvironmental conditions that occurred in the plant during resin exudation following wounding.

Structural changes in amber due to uranium mineralization.

The presence of uranium, with a bulk mass fraction of about 1.5 wt% and radiolytic alterations are a feature of Cenomanian amber from Krizany, at the northeastern edge of the North Bohemian Cretaceous uranium ore district. Pores and microcracks in the amber were filled with a mineral admixture, mainly in the form of Zr-Y-REE enriched uraninite. As a result of radiolytic alterations due to the presence of uranium, structural changes were observed in the Krizany amber in comparison with a reference amber from Nové Strasecí in central Bohemia; this was of similar age and botanical origin but did not contain elevated levels of uranium. Structural changes involved an increase in aromaticity due to dehydroaromatization of aliphatic cyclic hydrocarbons, loss of oxygen functional groups, an increase in the degree of polymerization, crosslinking of CC bonds, formation of a three-dimensional hydrocarbon network in the bulk organic matrix, and carbonization of the organic matrix around the uraninite infill.

A multi-instrumental geochemical study of anomalous uranium enrichment in coal.

Contents of uranium in coals from Oder in the northernmost part of the Sokolov Basin, Czech Republic, in the vicinity of the well known St. Joachimsthal uranium ore deposits, reach extremely high values. In the present work, coal samples with contents of uranium ranging from 0.02 to 6 wt.% were studied. The study employing a whole complex of analytical techniques has been aimed at identification of changes in the structure of coal organic matter, which are associated with the high contents of uranium in coal. The study includes proximate and ultimate analyses, multielement analysis by instrumental neutron and photon activation analyses, micropetrographic analysis by optical microscopy, ESEM/EDX analysis of mineral matter, infrared and Raman spectroscopies, solvent extraction followed by gas chromatography with mass spectroscopy (GC/MS), and analytical pyrolysis (Py-GC/MS). The study has confirmed previously proposed explanation of uraniferous mineralization in sedimentary carboniferous substances by the mechanism of reduction and fixation of soluble U(VI) (uranyl, UO2(2+)) species (e.g., humic, carbonate/hydroxo/phosphate complexes) by sedimentary organic matter under diagenetic or hydrothermal conditions, and formation of insoluble U(IV) species as phosphate minerals and uraninite. The process is accompanied with alteration and destruction of the coal organic matter. The changes in the structure of coal organic matter involve dehydrogenation and oxidation mainly in the aliphatic, aromatic and hydroxyl structures, and an increase in aromaticity, content of ether bonds, and the degree of coalification.

Geochemical distribution of polycyclic aromatic hydrocarbons in soils and sediments of El-Tabbin, Egypt.

Polycyclic aromatic hydrocarbons (PAHs) were extracted from 30 samples (24 soils and 6 stream sediments) collected in El-Tabbin area in the southern part of Greater Cairo, Egypt. Isopleth maps of PAHs clarified the regional variability and identified the most affected regions in the area suffering from high pollution. The total PAH concentrations were 53.4-5558.0 ng g(-1) in the sample extracts. The highest values were found in a soil sample near a coke factory, with the highest concentration of single PAHs, which were 1064.8 ng g(-1) of fluoranthene and 1286.4 ng g(-1) of phenanthrene. The calculated ratios and indexes allowed to elucidate origin of the organic compounds and to identify emission sources. The overall molecular patterns are signatures of pyrolysis of fossil fuels and biomass. Petrogenic contamination was recognised in the sediment samples due to petroleum products deliveries from ships. Also perylene was prominent especially in samples of the River Nile sediments as a diagenetic product of fungi. Other detailed information on petrogenic sources was provided by analysis of alkanes and calculation of alkane ratios.

Innovative technique for the direct determination of proteins in calcified aortic valves.

Aortal valve mineralization very frequently causes a genesis of aortic stenosis, which is the most often surgically treated heart disease. Hydroxyapatite deposits have been identified as one of the causes leading to the loss of elasticity of the aortic valves. It is known that phosphates/calcium is accumulated in valve tissues during mineralization, but the mechanism of this process remains unclear. The work is focused mainly on the study of protein composition of mineralized aortic valves by nano-liquid chromatography electrospray ionization in a quadrupole orthogonal acceleration time-of-flight mass spectrometry. New methodological approach based on direct enzymatic digestion of proteins contained in hydroxyapatite deposits was developed for the study of pathological processes connected with osteogenesis. Our objectives were to simplify the traditional analytical protocols of sample preparation and to analyze the organic components of the explanted aortic valves for significant degenerative aortic stenosis. The study of aortic valve mineralization on the molecular level should contribute to understanding this process, which should consequently lead to effective prevention as well as to new ways of treatment of this grave disease.

Toxicologically important trace elements and organic compounds investigated in size-fractionated urban particulate matter collected near the Prague highway.

Urban particulate matter was collected in the most exposed area of Prague, near a busy highway, in order to provide petrographic and chemical characterization useful for health impact assessment in that locality or other applications. Samples were collected from filters of the air conditioning system in two years, 2009 and 2010, and sieved into four grain-size fractions: 0.507-0.119 mm, 0.119-0.063 mm, <0.063 mm and sub-fraction <0.025 mm. Methods of destructive and non-destructive analyses were used for the determination of total analyte (As, Cd, Cr, Mn, Ni, Pb, Zn) contents. Labile forms of some toxicologically important analytes were tested in 2 M HNO(3) extracted solutions. A composition of inorganic and carbonaceous particles of natural and anthropogenic origin and their morphology were studied by optical and electron microscopy. Organic solvent extracts of the samples were analyzed using gas chromatography to compare the organic compound distribution in fractions. Only slight differences between 2009 and 2010 years are visible. The relatively high extractable part of most investigated elements confirms mobility and potential availability to organisms. The changes can be recognized in the petrographic and organic composition in samples from both years, which were likely the result of various inputs of source materials. Specific organic marker compounds indicate contribution from fossil fuels, plant materials and bacteria.

Carbon air pollution reflected in deposits on chosen building materials of Prague Castle.

Thin black surface layers or black coloured gypsum crusts can be observed on stones of many buildings and sculptures around the world. The black weathered stone and mortar surface from selected sections of the Prague Castle were studied by microscopic methods, GC/MS and pyrolysis-GC/MS analysis. Microscopically, we found an authigenic gypsum formation with an outer layer of an admixture of fine grains of quartz, clay minerals, thermally altered clay minerals, fly ash, and carbonaceous particles of natural and anthropogenic origin particularly chars, cokes, soots. Noncarbonate C content ranged between 0.8% and 4.3%. Phtalates dominated in extracts from the samples and benzonitrile had the greatest abundance in the pyrolysis products. The identified organic particles and compounds are known to result from human activities.

Sorption of metal ions on lignite and the derived humic substances.

The study presents results of sorption of metal ions (Pb2+, Zn2+, Cu2+, and Cd2+) onto lignite mined in South Moravia, Czech Republic, and solid humic substances (humin and humic acid) derived from it. The efficiency of these sorbents has been studied as a function of contact time, solution pH, and metal concentration. The sorption efficiencies were higher for humin and lower for humic acid samples than for the original lignite. With its high sorption capacities of several mmol/g, particularly for Pb2+ and Cd2+, the South Moravian lignite can provide a cheap source material for preparation of sorbents utilizable in removal of toxic metals from wastewaters.