Evidence and evolution of Criegee intermediates, hydroperoxides and secondary organic aerosols formed via ozonolysis of α-pinene

2020 ◽  
Vol 22 (12) ◽  
pp. 6528-6537 ◽  
Author(s):  
Arnab Bagchi ◽  
Youqing Yu ◽  
Jhih-Hong Huang ◽  
Cheng-Cheng Tsai ◽  
Wei-Ping Hu ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols ◽  
Time Resolved ◽  
Rapid Scan ◽  
Criegee Intermediates ◽  
Scan Time ◽  
Cooling Chamber ◽  
Ftir Spectrometer

The first experimental evidence of Criegee intermediates formed via α-pinene ozonolysis and the formation of secondary organic aerosols is reported using a rapid scan time-resolved FTIR spectrometer coupled with a long-path aerosol cooling chamber.

Rapid-Scan Time-Resolved FT-IR Spectroelectrochemistry Studies on the Electrochemical Redox Process

2007 ◽  
Vol 111 (7) ◽  
pp. 1517-1522 ◽  
Author(s):  
Baokang Jin ◽  
Peng Liu ◽  
Ye Wang ◽  
Zipin Zhang ◽  
Yupeng Tian ◽  
...  
Keyword(s):  
Redox Process ◽  
Time Resolved ◽  
Rapid Scan ◽  
Scan Time ◽  
Ft Ir ◽  
Electrochemical Redox

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.

Applications of Time-Resolved Step-Scan and Rapid-Scan FT-IR Spectroscopy: Dynamics from Ten Seconds to Ten Nanoseconds

1993 ◽  
Vol 47 (9) ◽  
pp. 1376-1381 ◽  
Author(s):  
T. J. Johnson ◽  
A. Simon ◽  
J. M. Weil ◽  
G. W. Harris
Keyword(s):  
Fourier Transform ◽  
Ir Spectroscopy ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Rapid Scan ◽  
Scan Time ◽  
Ft Ir ◽  
Complementary Nature ◽  
New Applications ◽  
Ft Ir Spectroscopy

The step-scan technique in Fourier transform infrared (FT-IR) spectroscopy is employed in new applications of time resolved spectroscopy (TRS). Results are demonstrated on time-resolved laser emissions and photolytically generated chemical reactions using both emission and absorption modes. New achievements in FT-IR temporal resolution are demonstrated, as well as the complementary nature of step-scan and rapid-scan time-resolved spectroscopy.

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 Construction of 40 Nanosecond Time Resolusion Step-Scan Ftir Difference Spectrometer

1999 ◽  
Vol 19 (1-4) ◽  
pp. 141-143
Author(s):  
Xuehua Hu ◽  
Thomas G. Spiro
Keyword(s):  
Fourier Transform ◽  
Time Resolution ◽  
Time Domain ◽  
Nd:Yag Laser ◽  
Transient Signals ◽  
Time Resolved ◽  
Pulsed Nd:Yag Laser ◽  
Scan Time ◽  
Ftir Spectrometer ◽  
The Time Domain

A step-scan time-resolved Fourier transform infrared (FTIR) spectrometer was constructed. Using 1064 nm radiation from a 9ns pulsed Nd:YAG laser as the IR source, we have obtained both the time-resolved spectra in the frequency domain and the change of the transient signals in the time domain. The latter allows us to measure the time resolution of the instrument to be about 40 nanoseconds.

scholarly journals Formation of secondary organic aerosols from the ozonolysis of dihydrofurans

2016 ◽  
Author(s):  
Yolanda Díaz de Mera ◽  
Alfonso Aranda ◽  
Larisa Bracco ◽  
Diana Rodriguez ◽  
Ana Rodriguez
Keyword(s):  
Relative Humidity ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Particle Number ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols ◽  
Organic Aerosol ◽  
Reaction Conditions ◽  
Criegee Intermediates ◽  
Computational Calculations

Abstract. In this work we report the study of the ozonolysis of 2,5-dihydrofuran and 2,3-dihydrofuran and the reaction conditions leading to the formation of secondary organic aerosols. The reactions have been carried out in a Teflon chamber filled with synthetic air mixtures at atmospheric pressure and room temperature. The ozonolysis only produced particles in the presence of SO2. Water vapour has no effect on the production of secondary organic aerosol in the case of 2,5-dihydrofuran while it reduces the particle number and particle mass concentrations from the 2,3-dihydrofuran ozonolysis. The water and SO2 rate constants ratio for the 2,3-dihydrofuran Criegee intermediate was derived from the SOA yields in experiments with different relative humidity values, kH2O/kSO2 = (9.8 &amp;pm; 3.7) ×10−5. The experimental results show that SO3 is not an intermediate in the formation or growth of new particles in contrast to the data reported for other Criegee intermediates/SO2 reactions. For the studied reactions, SO2 behaves as a catalyst in the production of condensable products. Computational calculations show that the stabilised Criegee intermediates from the ozonolysis reaction of both 2,5-dihydrofuran and 2,3-dihydrofuran may react with SO2 resulting in the regeneration of SO2 and the formation of organic acids.

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