170,452 research outputs found
Elemental speciation analysis, from environmental to biochemical challenge
No full textInformation regarding the distribution of
metallic/metalloid chemical species in biological compartments is required
for understanding their biochemical impact on living organisms. To obtain
such information implies the use of a dedicated measurement approach, namely
speciation analysis. The current trend in (elemental) speciation analysis regards bioinorganic
applications. New analytical methodologies are therefore necessary for
identification, detection and characterization of metal(loids) complexed or
incorporated into biomolecules. The established element-speciation
approaches developed for the determination of low molecular mass metal(loid)
species (e.g. organometallic compounds) in environmental, food,
toxicological and health sciences are presently being adapted for the
determination of high molecular mass metal-species, generally related to
biological processes. This is one of the newest approaches in terms of
element speciation and is called metallomics; this concept refers to the totality of
metal species in a cell and covers the inorganic element content and the
ensemble of its complexes with biomolecules, particularly proteins,
participating in the organisms' response to beneficial or harmful
conditions. Compared to conventional elemental speciation analysis, the
approach applied to bioinorganic analysis is challenging, particularly given
the difficulties in identification/characterization of the organic (e.g.
protein) content of such species. In addition, quantification is not
feasible with the conventional approaches, which led to the exploitation of
the unique feature of (post-column) online isotope dilution-mass
spectrometry for species quantification in metallomics
Climate-related variations in atmospheric Sb and Tl in the EPICA Dome C ice (East Antarctica) during the past 800,000 years
No full textA record of antimony (Sb) and thallium (Tl) from the European Project for Ice Coring in Antarctica (EPICA) Dome C Antarctic ice core provides the characteristics of climate-related natural changes in concentrations and fluxes of these toxic elements over the time period back to Marine Isotope Stage 20.2, similar to 800kyrB.P. A strong variability in concentrations and fluxes are observed for both elements, with considerably higher values during glacial maxima and lower values during intermediate and warm periods. Rock and soil dust accounts for, on average, 58% of Sb and 76% of Tl in ice during glacial maxima. This contribution remains significant during warm periods, accounting for 21% for Sb and 27% for Tl. The contribution from volcanoes appears to be very important particularly for Tl when climatic conditions become warmer, with an estimated volcanic contribution of 72% for Tl during interglacials. The sea-salt contribution is significant for Sb, particularly during intermediate climatic periods, with an average contribution of 17%. This sea-salt contribution is most likely caused by greater production of sea salt from highly saline frost flowers and relatively more efficient transport of Sb-enriched sea-ice salt from source areas on the East Antarctic Plateau. Our ice core data, along with snow data recently reported from the Antarctic snow layers at Dome Fuji, shows that the present-day Sb flux (6.6ng/m(2)/yr) is approximately double the highest natural level (2.8ng/m(2)/yr) during glacial maxima throughout the last successive eight glacial/interglacial cycles. This result indicates that human activity has induced the greatest perturbation of the atmospheric cycle of Sb ever experienced over a period of similar to 800 kyr in the most remote area on Earth
Soils as a record of the past
No full textOn the occasion of the EGU General Assembly 2012, researchers and students involved in interdisciplinary soil science studies were invited to submit abstracts to the session SSS10.2. Soils as a Record of the Past. This session, convened by Claudio Zaccone (Univ. of Foggia) and co-convened by Jan M. van Mourik (Univ. of Amsterdam), Carlo Barbante (Univ. of Venice) and Sjoerd J. Kluiving (Univ. of Amsterdam) (http://meetingorganizer.copernicus.org/EGU2012/session/9994), received numerous contributions regarding, only to mention some of the main topics, the application of new techniques to obtain palaeoecological and geoarchaeological information from different soil types, the application of different age-dating techniques to have reliable geochronological information, new reconstructions of vegetation and climate of the past through the integrated analysis of different terrestrial archives, the reconstructions of the human impact on the environment, in terms of organic and inorganic pollutant, land-use, fires, etc, and the reconstruction of soil forming environments of the past and the landscape evolution. In the present Special Issue, we present a selection of papers (8) in order to share the potential of soils as a record of the past with the community of geosciences
Benzina verde. Dalle nevi polari un segnale di riduzione della contaminazione ambientale da piombo.
No full textParma 23/5/2001. Atti del Convegno (Riass. Estesi), pp. 49-53
Benzina verde. Dalle nevi polari un segnale di riduzione della contaminazione ambientale da piombo.
No full textChemometric evaluation of the quality of a few components of the Venetian Lagoon ecosystem. Results of a pilot investigation.
No full textNanoscience, nanotechnology and spectrometry
No full textNanoscience has outgrown its infancy, and nanotechnology has found important applications in our daily life — with many more to come. Although the central concepts of the nano world, namely the changes of particular physical properties on the length scale of individual atoms and molecules, have been known and developed for quite some time already, experimental advances since the 1980s and recognition of the potential of nano- materials led to a genuine breakthrough of the inherently multidisciplinary nanoscience field. Analytical nanoscience and nanotechnology and especially the use of micro and nano electro mechanical systems, of the quantum dots and of mass spectrometry, currently provide one of the most promising avenues for developments in analytical science, derived from their two main fields of action, namely (a) the analysis of nano-structured materials and (b) their use as new tools for analysis. An overview is given of recent developments and trends in the field, highlighting the importance and point out future directions, while also touching drawbacks, such as emerging concerns about health and environmental issues
Direct ultra trace determination of lead and cadmium in Antarctic snow by differential pulse anodic stripping voltammetry
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