Organic aerosol (OA) represents a significant fraction of ambient aerosol. One of the largest primary sources of OA in the atmosphere is biomass burning (BB). In BB aerosol many different compounds can be present; their chemistry is highly variable and directly dependent on the chemical composition of the burning material and the combustion conditions. Some of these compounds are very specific to biomass burning; therefore, they can be used as markers. A well-established tracer compound for primary BBA is levoglucosan, which originates from the pyrolysis of cellulose or hemicellulose. Secondary BBA, which is formed after physical and chemical changes (aging) of the primary BBA in the atmosphere, contains more oxidized and polar compounds. An important class of compounds of secondary organic aerosols (SOA) is nitrocatechols, which are strong absorbers of UV and Vis light, and thus can affect the earth’s radiative balance and climate. They can have adverse effects on human health and on all living beings. Very recently, methyl-nitrocatechols were proposed as suitable markers for highly oxidized secondary BBA.
B.04 Guest lecture
COBISS.SI-ID: 36976901The University of Ljubljana, Slovenia is part of an international consortium which seeks to reveal the secrets behind the composition of elements in plant tissue. The partners bring together cutting-edge expertise on sample preparation and elemental and molecular imaging techniques to propel this exciting field forward.
D.04 Initiative to set up a new research area in Slovenia
COBISS.SI-ID: 2862159At a conference talk we presented the recent developments of 2D and 3D LA-ICP-MS elemental imaging for ancient glass. 2D imaging is based on laser rastering over the sample suface with subsequent "sum-normalization" calibration, yielding quantitative information for 54 measured elements, from trace to major, for each pixel of the map. This approach is unaffected by the instrumental drift, laser power and defocusing issues. We analyzed 2 Egyptian mosaic style glass artefacts (2000 year old). The 2D approach is excellent for the initial investigations of ancient manufacturing, raw materials and provenancing. 3D imaging is based on slow laser drilling on a virtual grid on the surface, followed by extraction of depth maps along the z-axis. Using a burst of 50 laser shots at 1 Hz on each point of the grid, each laser shot is related to a specific voxel with a size of 90 x 90 x 0.15 μm and a content of 19 elemens. We tested the approach by investigation of the degradation mechanisms of a medieval, weathered glass artifact by colocalization analysis of selected cross-sectional 2D elemental images in arbitrary planes of the volume images.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 5322778The latest results of our investigations in the field of bismuth- and antimony- based electrodes for measuring (trace) metal ions and selected organic compounds, using either electrochemical stripping protocols or direct voltammetry were presented; also a critical comparison was given versus their mercury counterparts.
B.04 Guest lecture
COBISS.SI-ID: 5265434The research work which was carried out in the frame of doctoral dissertation by Hanna Ingrid Sopha was focused on studies and preparation of different types of bismuth- and antimony-based electrodes as excellent replacements for the most commonly used mercury electrode, and on investigation of their electroanalytical performances and possibilities for their broader applications in measuring trace metal ions and selected organic compounds in combination with advanced electrochemical (stripping) techniques. Bismuth and antimony electrode have gained a wide interest in the last decade (J. Wang, J. Lu, S.B. Hocevar, P.A.M. Farias, B. Ogorevc, Anal. Chem. 72 (2000) 3218 and S.B. Hocevar, I. Svancara, B. Ogorevc, K. Vytras, Anal. Chem. 79 (2007) 8639), therefore the candidate's work was dedicated to this attractive theme.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 266044416