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Thermodynamic Study of Water Activity in Atmospheric Aerosol Particles.
Asadzadeh, Behnaz ; Bendová, Magdalena ; Ždímal, Vladimír
Atmospheric aerosols are complex mixtures of various inorganic−organic compounds and play significant roles in atmospheric chemistry, earth’s climate, and global radiation budget as well as in human health. Hygroscopicity is the ability of the particle to uptake water from surrounding environment. Hygroscopicity can directly control the size distribution, chemical reactivity, and phase state of aerosol particles and thus contribute to radiative forcing on the climate system, including both the direct forcing by absorbing or scattering light and indirect forcing through activation of cloud condensation nuclei (CCN). Interactions between inorganic−organic may have a crucial impact on the hygroscopic behaviour of aerosol droplets and lead to discrepancies from ideal thermodynamic behavior. The non-ideality of mixtures in aerosol particles influences the gas-particle partitioning and affects the physical state of the condensed phase, potentially leading to liquid-liquid phase separation. Thermodynamic models are key tools to gain insight into the non-ideal behavior of organic-inorganic mixtures. By means of activity coefficients, non-ideal behaviour can be taken into account. In this study we developed a thermodynamic segment-based local composition model named NRTL (Non Random Two Liquid) to describe the aktivity coefficients of organic and inorganic aerosol particles.\n
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22019110512053 - PDF
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NMR Aerosolomics as a Tool to Distinguish Various Types of Aerosols.
Horník, Štěpán ; Schwarz, Jaroslav ; Ždímal, Vladimír ; Sýkora, Jan
Water-soluble organic compounds represent up to 80% of all organic compounds present in atmospheric aerosols. Unlike composition of inorganic compounds or volatile organic compounds, which seems to be well explored, the knowledge about WSOC composition is still rather limited. The most frequently used method for WSOC analysis is GC-MS, which is a very sensitive technique. However, the analysis of polar compounds via GC-MS requires derivatization and the quantification is extremely time consuming. The second widely used technique is ion chromatography (IC). Nowadays, IC is routinely used for analysis of specific groups of organic compounds such as carboxylic acids, amines or carbohydrates. On the other hand, there is NMR spectroscopy as a fully quantitative but rather insensitive method. NMR spectroscopy was for the purpose of aerosol chemistry employed only recently as this technique has undergone rapid development and sensitivity gain of late. So far, the use of NMR spectroscopy is mainly restricted to socalled Functional Group Analysis, of which main interest lies elsewhere than in identification of individual compounds.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019110512330 - PDF
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Origin of Atmospheric Aerosol Based on Data with Different Time Resolution at the National Atmospheric Observatory Košetice.
Pokorná, Petra ; Zíková, Naděžda ; Lhotka, Radek ; Vodička, Petr ; Makeš, Otakar ; Mbengue, Saliou ; Holubová Šmejkalová, Adéla ; Schwarz, Jaroslav ; Ondráček, Jakub ; Ždímal, Vladimír
To improve the air quality the underlying causalities must be well understood,particularly when it comes to aspects such as PM concentration, sources and their origin. The aim of this work was to determine air pollution origin at NAOK based on atmospheric aerosol (AA) data of different time resolution measured during intensive summer campaing.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019110512031 - PDF
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Identification of Sources of Polycyclic Aromatic Hydrocarbons in Central Europe.
Lhotka, Radek ; Pokorná, Petra ; Zíková, Naděžda
This study evaluates the trends and sources of polycyclic aromatic hydrocarbons (PAH) monitored at National atmospheric observatory Košetice (NAOK), a rural background site. In total, 14 PAH concentrations in particulate matter (PM10) between 2006 and 2016 were evaluated. The highest concentrations of all PAH were measured at the beginning of the study period, in 2006. The positive matrix factorization (EPA PMF 5.0) was used to determine the sources of PAH at NAOK, with three factors resolved. The probable origin areas of PMF factors were identified by Conditional Bivariate Probability Function method (CBPF) and Potential Source Contribution Function method (PSCF) methods. NAOK is affected by local sources of PAH, as well as by regional and long-range transport.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019110511050 - PDF
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ACTRIS IMP – ÚČAST ČESKÉ REPUBLIKY V NÁRODNÍCH VÝZKUMNÝCH INFRASTRUKTURÁCH A TÉMATICKÝCH CENTRECH ACTRIS
Ondráček, Jakub ; Váňa, M. ; Klánová, J. ; Holoubek, Ivan ; Ždímal, V.
ACTRIS (The Aerosol, Clouds and Trace Gases Research Infrastructure) je panevropskou výzkumnou infrastrukturou, jejímž hlavním cílem je tvorba vysoce kvalitních dat a podávání informací o krátkodobých složkách atmosféry a o procesech vedoucích ke změnám těchto složek v přírodním a kontrolovaném laboratorním prostředí. ACTRIS je dlouhodobou aktivitou (již od roku 2012, viz. Obr. 1) více než 100 partnerských organizací po celé Evropě, jejichž cílem je integrace, harmonizace a distribuce vysoce kvalitních vědeckých výstupů poskytovaných nejlepšími pracovišti atmosférického výzkumu v (prozatím) 22 evropských zemích. ACTRIS je logickým pokračováním 15-tiletého rozvoje velkých výzkumných infrastruktur financovaného členskými státy a evropskou komisí (EC) prostřednictvím programu výzkumných infrastruktur (Research Infrastructure programme) zahrnujících např. Projekty EARLINET, EUSAAR, CREATE a CLOUDNET.
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NMR Aerosolomics as a Tool to Distinguish Various Types of Aerosol Samples.
Horník, Štěpán ; Schwarz, Jaroslav ; Ždímal, Vladimír ; Sýkora, Jan
In the recent study, the summer and winter aerosol samples were analyzed using NMR aerosolomics approach. The samples were collected in Prague-Suchdol during summer 2008 and winter 2009 in two different particle size fractions - PM2.5 and PM 10. Around 50 compounds were identified in each aerosol spectrum owing to the comprehensive library. The profile of 86 identified compounds, which were identified in the samples altogether, served as an input data for statistical analysis. Multivariate statistical analysis clearly discriminates the two groups studied. Furthermore, it is possible to determine the most significant compounds.
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NMR Aerosolomics as a Tool to Distinguish Various Types of Aerosol Samples.
Horník, Štěpán ; Schwarz, Jaroslav ; Ždímal, Vladimír ; Sýkora, Jan
In the recent study, the summer and winter aerosol samples were analyzed using NMR aerosolomics approach. The samples were collected in Prague-Suchdol during summer 2008 and winter 2009 in two different particle size fractions - PM2.5 and PM 10. Around 50 compounds were identified in each aerosol spectrum owing to the comprehensive library. The profile of 86 identified compounds, which were identified in the samples altogether, served as an input data for statistical analysis. Multivariate statistical analysis clearly discriminates the two groups studied. Furthermore, it is possible to determine the most significant compounds.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019041208492 - PDF
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