Combined Determination of the Chemical Composition and of Health Effects of Secondary Organic Aerosols: The POLYSOA Project

2008 ◽  
Vol 0 (0) ◽  
pp. 080207080519480-10 ◽  
Author(s):  
Urs Baltensperger ◽  
Josef Dommen ◽  
M. Rami Alfarra ◽  
Jonathan Duplissy ◽  
Kathrin Gaeggeler ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Health Effects ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols

Combined Determination of the Chemical Composition and of Health Effects of Secondary Organic Aerosols: The POLYSOA Project

2008 ◽  
Vol 21 (1) ◽  
pp. 145-154 ◽  
Author(s):  
Urs Baltensperger ◽  
Josef Dommen ◽  
M. Rami Alfarra ◽  
Jonathan Duplissy ◽  
Kathrin Gaeggeler ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Health Effects ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols

scholarly journals Comparison between simulated and observed chemical composition of fine aerosols in Paris (France) during springtime: contribution of regional versus continental emissions

2010 ◽  
Vol 10 (24) ◽  
pp. 11987-12004 ◽  
Author(s):  
J. Sciare ◽  
O. d'Argouges ◽  
Q. J. Zhang ◽  
R. Sarda-Estève ◽  
C. Gaimoz ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Secondary Organic Aerosols ◽  
Transport Model ◽  
Organic Aerosols ◽  
Carbonaceous Material ◽  
Chemical Components ◽  
Carbonaceous Aerosols ◽  
Time Resolved ◽  
Air Masses ◽  
North Western

Abstract. Hourly concentrations of inorganic salts (ions) and carbonaceous material in fine aerosols (aerodynamic diameter, A.D. <2.5 μm) have been determined experimentally from fast measurements performed for a 3-week period in spring 2007 in Paris (France). The sum of these two chemical components (ions and carbonaceous aerosols) has shown to account for most of the fine aerosol mass (PM2.5). This time-resolved dataset allowed investigating the factors controlling the levels of PM2.5 in Paris and showed that polluted periods with PM2.5 > 15 μg m−3 were characterized by air masses of continental (North-Western Europe) origin and chemical composition made by 75% of ions. By contrast, periods with clean marine air masses have shown the lowest PM2.5 concentrations (typically of about 10 μg m−3); carbonaceous aerosols contributing for most of this mass (typically 75%). In order to better discriminate between local and continental contributions to the observed chemical composition and concentrations of PM2.5 over Paris, a comparative study was performed between this time-resolved dataset and the outputs of a chemistry transport model (CHIMERE), showing a relatively good capability of the model to reproduce the time-limited intense maxima observed in the field for PM2.5 and ion species. Different model scenarios were then investigated switching off local and European (North-Western and Central) emissions. Results of these scenarios have clearly shown that most of the ions observed over Paris during polluted periods, were either transported or formed in-situ from gas precursors transported from Northern Europe. On the opposite, long-range transport from Europe appeared to weakly contribute to the levels of carbonaceous aerosols observed over Paris. The model failed to properly account for the concentration levels and variability of secondary organic aerosols (SOA) determined experimentally by the EC-tracer method. The abundance of SOA (relatively to organic aerosol, OA) was as much as 75%, showing a weak dependence on air masses origin. Elevated SOA/OA ratios were also observed for air masses having residence time above ground of less than 10 h, suggesting intense emissions and/or photochemical processes leading to rapid formation of secondary organic aerosols.

scholarly journals Comparison between simulated and observed chemical composition of fine aerosols in Paris (France) during springtime: contribution of regional versus continental emissions

2010 ◽  
Vol 10 (7) ◽  
pp. 16861-16900
Author(s):  
J. Sciare ◽  
O. d'Argouges ◽  
R. Sarda-Estève ◽  
C. Gaimoz ◽  
V. Gros ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Secondary Organic Aerosols ◽  
Transport Model ◽  
Organic Aerosols ◽  
Carbonaceous Material ◽  
Chemical Components ◽  
Carbonaceous Aerosols ◽  
Time Resolved ◽  
Air Masses ◽  
North Western

Abstract. Hourly concentrations of inorganic salts (ions) and carbonaceous material in fine aerosols (aerodynamic diameter, A.D.<2.5 μm) have been determined experimentally from fast measurements performed for a 3-week period in spring 2007 in Paris (France). The sum of these two chemical components (ions and carbonaceous aerosols) has shown to account for most of the fine aerosol mass (PM2.5). This time-resolved dataset allowed investigating the factors controlling the levels of PM2.5 in Paris and showed that polluted periods with PM2.5<15 μg/m3 were characterized by air masses of continental (North-Western Europe) origin and chemical composition made by 75% of ions. By contrast, periods with clean marine air masses have shown the lowest PM2.5 concentrations (typically of about 10 μg/m3); carbonaceous aerosols contributing for most of this mass (typically 75%). In order to better discriminate between regional and continental contributions to the observed chemical composition and concentrations of PM2.5 over Paris, a comparative study was performed between this time-resolved dataset and the outputs of a chemistry transport model (CHIMERE), showing a relatively good capability of the model to reproduce the time-limited intense maxima observed in the field for PM2.5 and ion species. Different model scenarios were then investigated switching off regional and European (North-Western and Central) emissions. Results of these scenarios have clearly shown that most of the ions observed over Paris during polluted periods, were either transported or formed in-situ from gas precursors transported from Northern Europe. By opposite, long-range transport from Europe appeared to poorly contribute to the levels of carbonaceous aerosols observed over Paris. The model failed to properly account for the concentration levels and variability of secondary organic aerosols (SOA) determined experimentally by the EC-tracer method. The abundance of SOA (relatively to organic aerosol, OA) was as much as 75%, showing a poor dependence on air masses origin. Elevated SOA/OA ratios were also observed for air masses having residence time above ground for less than 10 h, suggesting intense emissions and/or photochemical processes leading to rapid formation of secondary organic aerosols.

scholarly journals Differentiating between primary and secondary organic aerosols of biomass burning in an environmental chamber with FTIR and AMS

2021 ◽  
Author(s):  
Amir Yazdani ◽  
Satoshi Takahama ◽  
Jack K. Kodros ◽  
Marco Paglione ◽  
Mauro Masiol ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Temporal Resolution ◽  
Biomass Burning ◽  
Secondary Organic Aerosols ◽  
Bulk Composition ◽  
Organic Aerosols ◽  
Chamber Wall ◽  
High Temporal Resolution ◽  
Environmental Chamber ◽  
Primary Emissions

&lt;p&gt;Fine particulate matter (PM) affects visibility, climate and public health. Organic matter (OM), which is hard to characterize due to its complex chemical composition, can constitute more than half of the PM. Biomass burning from residential wood burning, wildfires, and prescribed burning is a major source of OM with an ever-increasing importance.&lt;/p&gt;&lt;p&gt;&amp;#160; &amp;#160; Aerosol mass spectrometry (AMS) and Fourier transform infrared spectroscopy (FTIR) are two complementary methods of identifying the chemical composition of OM. AMS measures the bulk composition of OM with relatively high temporal resolution but provides limited parent compound information. FTIR, carried out on samples collected on Teflon filters, provides detailed functional groupinformation at the expense of relatively low temporal resolution.&lt;/p&gt;&lt;p&gt;&amp;#160; &amp;#160; In this study, we used these two methods to better understand the evolution of biomass burning OM in the atmosphere with aging. For this purpose, primary emissions from wood and pellet stoves were injected into the Center for Studies of Air Qualities and Climate Change (C-STACC) environmental chamber at ICE-HT/FORTH. Primary emissions were aged using hydroxyl and nitrate radicals (with atmospherically relevant exposures) simulating atmospheric day-time and night-time oxidation.&amp;#160; A time-of-flight (ToF) AMS reported the composition of non-refractory PM&lt;sub&gt;1&amp;#160;&lt;/sub&gt;every three minutes and PM&lt;sub&gt;1&amp;#160;&lt;/sub&gt;was collected on PTFE filters over 20-minute periods before and after aging for off-line FTIR analysis.&lt;/p&gt;&lt;p&gt;&amp;#160; &amp;#160; We found that AMS and FTIR measurements agreed well in terms of measured OM mass concentration, the OM:OC ratio, and concentration of biomass burning tracers &amp;#8211; lignin and levoglucosan. AMS OM concentration was used to estimate chamber wall loss rates which were then used separate the contribution of primary and secondary organic aerosols (POA and SOA) to the aged OM. AMS mass spectra and FTIR spectra of biomass burning SOA and estimates of bulk composition were obtained by this procedure. FTIR and AMS spectra of SOA produced by OH oxidation of biomass burning volatile organic compounds (VOCs) were dominated by acid signatures. Organonitrates, on the other hand, appeared to be important in the SOA aged by the nitrate radical. The spectra from the two instruments also indicated that the signatures of certain compounds such as levoglucosan, lignin and hydrocarbons, which are abundant in biomass burning POA, diminish with aging significantly more than what can be attributed to chamber wall losses. The latter suggests biomass burning POA chemical composition might change noticeably due to heterogeneous reactions or partitioning in the atmosphere. Therefore, the common assumption of stable POA composition is only partially true. In addition, more stable biomass burning tracers should be used to be able to identify highly aged biomass burning aerosols in the atmosphere.&lt;/p&gt;

Preparation of graft copolymers by the reaction of polymeric acyl chlorides with monohydroxy-terminated polymers: An introductory study

1988 ◽  
Vol 53 (8) ◽  
pp. 1735-1744 ◽  
Author(s):  
Jitka Horská ◽  
Jaroslav Stejskal ◽  
Pavel Kratochvíl ◽  
Aubrey D. Jenkins ◽  
Eugenia Tsartolia ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Statistical Model ◽  
Graft Copolymers ◽  
Coupling Reaction ◽  
Molecular Characteristics ◽  
Gel Formation ◽  
Acyl Chlorides ◽  
Molecular Weights

An attempt was made to prepare well-defined graft copolymers by the coupling reaction between acyl chloride groups located along the backbone chain and monohydroxy-terminated grafts prepared separately. The molecular weights and the parameters of heterogeneity in chemical composition of the products were determined by light scattering and osmometry. The determination of molecular characteristics revealed that the degree of grafting was low. The results therefore could not be confronted with a statistical model at this stage. The problems encountered in the synthesis, e.g., gel formation, and the data relating to the soluble products are discussed.

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