scholarly journals Estimation of the volatility distribution of organic aerosol combining thermodenuder and isothermal dilution measurements

2017 ◽  
Vol 10 (10) ◽  
pp. 3909-3918 ◽  
Author(s):  
Evangelos E. Louvaris ◽  
Eleni Karnezi ◽  
Evangelia Kostenidou ◽  
Christos Kaltsonoudis ◽  
Spyros N. Pandis
Keyword(s):  
Organic Compounds ◽  
Organic Aerosol ◽  
Accommodation Coefficient ◽  
Vaporization Enthalpy ◽  
Semivolatile Organic Compounds ◽  
Scanning Mobility Particle Sizer ◽  
Aerosol Mass ◽  
Clean Air ◽  
Particle Sizer ◽  
Almost All

Abstract. A method is developed following the work of Grieshop et al. (2009) for the determination of the organic aerosol (OA) volatility distribution combining thermodenuder (TD) and isothermal dilution measurements. The approach was tested in experiments that were conducted in a smog chamber using organic aerosol (OA) produced during meat charbroiling. A TD was operated at temperatures ranging from 25 to 250 °C with a 14 s centerline residence time coupled to a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a scanning mobility particle sizer (SMPS). In parallel, a dilution chamber filled with clean air was used to dilute isothermally the aerosol of the larger chamber by approximately a factor of 10. The OA mass fraction remaining was measured as a function of temperature in the TD and as a function of time in the isothermal dilution chamber. These two sets of measurements were used together to estimate the volatility distribution of the OA and its effective vaporization enthalpy and accommodation coefficient. In the isothermal dilution experiments approximately 20 % of the OA evaporated within 15 min. Almost all the OA evaporated in the TD at approximately 200 °C. The resulting volatility distributions suggested that around 60–75 % of the cooking OA (COA) at concentrations around 500 µg m−3 consisted of low-volatility organic compounds (LVOCs), 20–30 % of semivolatile organic compounds (SVOCs), and around 10 % of intermediate-volatility organic compounds (IVOCs). The estimated effective vaporization enthalpy of COA was 100 ± 20 kJ mol−1 and the effective accommodation coefficient was 0.06–0.07. Addition of the dilution measurements to the TD data results in a lower uncertainty of the estimated vaporization enthalpy as well as the SVOC content of the OA.

scholarly journals Estimation of the volatility distribution of organic aerosol combining thermodenuder and isothermal dilution measurements

2017 ◽  
Author(s):  
Evangelos E. Louvaris ◽  
Eleni Karnezi ◽  
Evangelia Kostenidou ◽  
Christos Kaltsonoudis ◽  
Spyros N. Pandis
Keyword(s):  
Organic Compounds ◽  
Organic Aerosol ◽  
Accommodation Coefficient ◽  
Vaporization Enthalpy ◽  
Scanning Mobility Particle Sizer ◽  
Aerosol Mass ◽  
Clean Air ◽  
Dilution Experiments ◽  
Particle Sizer ◽  
Almost All

Abstract. A method is developed for the determination of the organic aerosol (OA) volatility distribution combining thermodenuder and isothermal dilution measurements. The approach was tested in experiments that were conducted in a smog chamber using organic aerosol (OA) produced during meat charbroiling. A thermodenuder (TD) was operated at temperatures ranging from 25 to 250 °C with a 14 s centerline residence time coupled to a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and a Scanning Mobility Particle Sizer (SMPS). In parallel, a dilution chamber filled with clean air was used to dilute isothermally the aerosol of the larger chamber by approximately a factor of 10. The OA mass fraction remaining was measured as a function of temperature in the TD and as a function of time in the isothermal dilution chamber. These two sets of measurements were used together to estimate the volatility distribution of the OA and its effective vaporization enthalpy and accommodation coefficient. In the isothermal dilution experiments approximately 20 % of the OA evaporated within 15 min. Almost all the OA evaporated in the TD at approximately 200 °C. The resulting volatility distributions suggested that around 60–75 % of the cooking OA (COA) at concentrations around 500 μg m−3 consisted of low volatility organic compounds (LVOCs), 20–30 % of semi-volatile organic compounds (SVOCs) and around 10 % of intermediate volatility organic compounds (IVOCs). The estimated effective vaporization enthalpy of COA was 100 ± 20 kJ mol−1 and the effective accommodation coefficient was 0.06–0.07. Addition of the dilution measurements to the TD data results in a lower uncertainty of the estimated vaporization enthalpy as well as the SVOC content of the OA.

scholarly journals Aerosol light absorption and the role of extremely low volatility organic compounds

2020 ◽  
Vol 20 (19) ◽  
pp. 11625-11637
Author(s):  
Antonios Tasoglou ◽  
Evangelos Louvaris ◽  
Kalliopi Florou ◽  
Aikaterini Liangou ◽  
Eleni Karnezi ◽  
...  
Keyword(s):  
Black Carbon ◽  
Organic Compounds ◽  
Light Absorption ◽  
Absorption Enhancement ◽  
Scanning Mobility Particle Sizer ◽  
Brown Carbon ◽  
Aerosol Absorption ◽  
Aerosol Mass ◽  
Particle Sizer

Abstract. A month-long set of summertime measurements in a remote area in the Mediterranean is used to quantify aerosol absorption and the role of black and brown carbon. The suite of instruments included a high-resolution aerosol mass spectrometer (HR-ToF-AMS) and a scanning mobility particle sizer (SMPS), both coupled to a thermodenuder and an Aethalometer, a photoacoustic extinctiometer (PAX405), and a single particle soot photometer (SP2). The average refractory black carbon (rBC) concentration during the campaign was 0.14 µg m−3, representing 3 % of the fine aerosol mass. The measured light absorption was two or more times higher than that of fresh black carbon (BC). Mie theory indicated that the absorption enhancement due to the coating of BC cores by nonrefractory material could explain only part of this absorption enhancement. The role of brown carbon (BrC) and other non-BC light-absorbing material was then investigated. A good correlation (R2=0.76) between the unexplained absorption and the concentration of extremely low volatility organic compounds (ELVOCs) mass was found.

scholarly journals Measurement of the ambient organic aerosol volatility distribution: application during the Finokalia Aerosol Measurement Experiment (FAME-2008)

2010 ◽  
Vol 10 (24) ◽  
pp. 12149-12160 ◽  
Author(s):  
B. H. Lee ◽  
E. Kostenidou ◽  
L. Hildebrandt ◽  
I. Riipinen ◽  
G. J. Engelhart ◽  
...  
Keyword(s):  
Particle Density ◽  
Collection Efficiency ◽  
Eastern Mediterranean ◽  
Organic Aerosol ◽  
Accommodation Coefficient ◽  
Scanning Mobility Particle Sizer ◽  
Aerosol Dynamics ◽  
Aerosol Measurement ◽  
Measurement Experiment ◽  
Particle Sizer

Abstract. A variable residence time thermodenuder (TD) was combined with an Aerodyne Aerosol Mass Spectrometer (AMS) and a Scanning Mobility Particle Sizer (SMPS) to measure the volatility distribution of aged organic aerosol in the Eastern Mediterranean during the Finokalia Aerosol Measurement Experiment in May of 2008 (FAME-2008). A new method for the quantification of the organic aerosol volatility distribution was developed combining measurements of all three instruments together with an aerosol dynamics model. Challenges in the interpretation of ambient thermodenuder-AMS measurements include the potential resistances to mass transfer during particle evaporation, the effects of particle size on the evaporated mass fraction, the changes in the AMS collection efficiency and particle density as the particles evaporate partially in the TD, and finally potential losses inside the TD. Our proposed measurement and data analysis method accounts for all of these problems combining the AMS and SMPS measurements. The AMS collection efficiency of the aerosol that passed through the TD was found to be approximately 10% lower than the collection efficiency of the aerosol that passed through the bypass. The organic aerosol measured at Finokalia is approximately 2 or more orders of magnitude less volatile than fresh laboratory-generated monoterpene (α-pinene, β-pinene and limonene under low NOx conditions) secondary organic aerosol. This low volatility is consistent with its highly oxygenated AMS mass spectrum. The results are found to be highly sensitive to the mass accommodation coefficient of the evaporating species. This analysis is based on the assumption that there were no significant reactions taking place inside the thermodenuder.

scholarly journals Aerosol light absorption and the role of extremely low volatility organic compounds

2020 ◽  
Author(s):  
Antonios Tasoglou ◽  
Evangelos Louvaris ◽  
Kalliopi Florou ◽  
Aikaterini Liangou ◽  
Eleni Karnezi ◽  
...  
Keyword(s):  
Black Carbon ◽  
Organic Compounds ◽  
Light Absorption ◽  
Absorption Enhancement ◽  
Scanning Mobility Particle Sizer ◽  
Brown Carbon ◽  
Aerosol Absorption ◽  
Aerosol Mass ◽  
Particle Sizer

Abstract. A month-long set of summertime measurements in a remote area in the Mediterranean is used to quantify aerosol absorption and the role of black and brown carbon. The suite of instruments included a high-resolution Aerosol Mass Spectrometer (HR-ToF-AMS), and a Scanning Mobility Particle Sizer (SMPS) both coupled to a thermodenuder and an aethalometer, a photoacoustic extinctiometer (PAX405), a Multi-Angle Absorption Photometer (MAAP), and a Single Particle Soot Photometer (SP2). The average refractory black carbon (rBC) concentration during the campaign was 0.14 μg m−3, representing 3 % of the fine aerosol mass. The measured light absorption was two or more times higher than that of fresh black carbon (BC). Mie theory indicated that the absorption enhancement due to the coating of BC cores by non-refractory material could explain only part of this absorption enhancement. The role of brown carbon (BrC) and other non-BC light-absorbing material was then investigated. A good correlation (R2 = 0.65) between the unexplained absorption and the concentration of extremely low volatility organic compounds (ELVOCs) mass was found.

scholarly journals Measurement of the ambient organic aerosol volatility distribution: application during the Finokalia Aerosol Measurement Experiment (FAME-2008)

2010 ◽  
Vol 10 (7) ◽  
pp. 17435-17466 ◽  
Author(s):  
B. H. Lee ◽  
E. Kostenidou ◽  
L. Hildebrandt ◽  
I. Riipinen ◽  
G. J. Engelhart ◽  
...  
Keyword(s):  
Particle Density ◽  
Collection Efficiency ◽  
Eastern Mediterranean ◽  
Organic Aerosol ◽  
Accommodation Coefficient ◽  
Scanning Mobility Particle Sizer ◽  
Aerosol Dynamics ◽  
Aerosol Measurement ◽  
Measurement Experiment ◽  
Particle Sizer

Abstract. A variable residence time thermodenuder (TD) was combined with an Aerodyne Aerosol Mass Spectrometer (AMS) and a Scanning Mobility Particle Sizer (SMPS) to measure the volatility distribution of aged organic aerosol in the Eastern Mediterranean during the Finokalia Aerosol Measurement Experiment in May of 2008 (FAME-2008). A new method for the quantification of the organic aerosol volatility distribution was developed combining measurements of all three instruments together with an aerosol dynamics model. Challenges in the interpretation of ambient thermodenuder-AMS measurements include the potential resistances to mass transfer during particle evaporation, the effects of particle size on the evaporated mass fraction, the changes in the AMS collection efficiency and particle density as the particles evaporate partially in the TD, and finally potential losses inside the TD. Our proposed measurement and data analysis method accounts for all of these problems combining the AMS and SMPS measurements. The AMS collection efficiency of the aerosol that passed through the TD was found to be approximately 10% lower than the collection efficiency of the aerosol that passed through the bypass. The organic aerosol measured at Finokalia is approximately 2 orders of magnitude less volatile than fresh laboratory-generated biogenic secondary organic aerosol. This low volatility is consistent with its highly oxygenated AMS mass spectrum. The results are found to be highly sensitive to the mass accommodation coefficient of the evaporating species.

scholarly journals Sources and atmospheric processing of organic aerosol in the Mediterranean: insights from aerosol mass spectrometer factor analysis

2011 ◽  
Vol 11 (23) ◽  
pp. 12499-12515 ◽  
Author(s):  
L. Hildebrandt ◽  
E. Kostenidou ◽  
V. A. Lanz ◽  
A. S. H. Prevot ◽  
U. Baltensperger ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Mass Spectrometer ◽  
Organic Aerosol ◽  
Late Winter ◽  
Scanning Mobility Particle Sizer ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Atmospheric Processing ◽  
Measurement Experiment ◽  
Particle Sizer

Abstract. Atmospheric particles were measured in the late winter (25 February–26 March 2009) at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2009. A quadrupole aerosol mass spectrometer (Q-AMS) was employed to quantify the size-resolved chemical composition of non-refractory submicron aerosol, and a thermodenuder was used to analyze the organic aerosol (OA) volatility. Complementary measurements included particle size distributions from a scanning mobility particle sizer, inorganic and organic particle composition from filter analysis, air ion concentrations, O3, NOx and NOy concentrations, and meteorological measurements. Factor analysis was performed on the OA mass spectra, and the variability in OA composition could best be explained with three OA components. The oxygenated organic aerosol (OOA) was similar in composition and volatility to the summertime OA previously measured at this site and may represent an effective endpoint in particle-phase oxidation of organics. The two other OA components, one associated with amines (Amine-OA) and the other probably associated with the burning of olive branches (OB-OA), had very low volatility but were less oxygenated. Hydrocarbon-like organic aerosol (HOA) was not detected. The absence of OB-OA and Amine-OA in the summer data may be due to lower emissions and/or photochemical conversion of these components to OOA.

scholarly journals Sources and atmospheric processing of organic aerosol in the Mediterranean: insights from aerosol mass spectrometer factor analysis

2011 ◽  
Vol 11 (7) ◽  
pp. 19639-19682 ◽  
Author(s):  
L. Hildebrandt ◽  
E. Kostenidou ◽  
V. A. Lanz ◽  
A. S. H. Prevot ◽  
U. Baltensperger ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Mass Spectrometer ◽  
Organic Aerosol ◽  
Scanning Mobility Particle Sizer ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Atmospheric Processing ◽  
Measurement Experiment ◽  
Particle Sizer ◽  
Organic Particle

Abstract. Atmospheric particles were measured in the winter at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2009. A Quadrupole aerosol mass spectrometer (Q-AMS) was employed to quantify the size-resolved chemical composition of non-refractory submicron aerosol, and a thermodenuder was used to analyze the organic aerosol (OA) volatility. Complementary measurements included particle size distributions from a scanning mobility particle sizer, inorganic and organic particle composition from filter analysis, concentrations of O3, NOx and NOy, and meteorological measurements. Factor analysis was performed on the OA mass spectra, and the variability in OA composition could best be explained with three OA components. The oxygenated organic aerosol (OOA) was similar in composition and volatility to the summertime OA previously measured at this site and appears to represent an effective endpoint in particle-phase oxidation of organics. The two other OA components, one associated with amines (Amine-OA) and the other probably associated with the burning of olive branches (OB-OA), had lower volatility but were less oxygenated. Hydrocarbon-like organic aerosol (HOA) was not detected. The absence of OB-OA and Amine-OA in the summer data may be due to lower emissions and/or photochemical conversion of these components to OOA.

scholarly journals Measuring the atmospheric organic aerosol volatility distribution: a theoretical analysis

2014 ◽  
Vol 7 (9) ◽  
pp. 2953-2965 ◽  
Author(s):  
E. Karnezi ◽  
I. Riipinen ◽  
S. N. Pandis
Keyword(s):  
Experimental Approach ◽  
Organic Aerosol ◽  
Accommodation Coefficient ◽  
Vaporization Enthalpy ◽  
Typical Result ◽  
Volatile Components ◽  
Particulate Phase ◽  
Aerosol Mass ◽  
Mass Accommodation Coefficient ◽  
Atmospheric Concentrations

Abstract. Organic compounds represent a significant fraction of submicrometer atmospheric aerosol mass. Even if most of these compounds are semi-volatile in atmospheric concentrations, the ambient organic aerosol volatility is quite uncertain. The most common volatility measurement method relies on the use of a thermodenuder (TD). The aerosol passes through a heated tube where its more volatile components evaporate, leaving the less volatile components behind in the particulate phase. The typical result of a thermodenuder measurement is the mass fraction remaining (MFR), which depends, among other factors, on the organic aerosol (OA) vaporization enthalpy and the accommodation coefficient. We use a new method combining forward modeling, introduction of "experimental" error, and inverse modeling with error minimization for the interpretation of TD measurements. The OA volatility distribution, its effective vaporization enthalpy, the mass accommodation coefficient and the corresponding uncertainty ranges are calculated. Our results indicate that existing TD-based approaches quite often cannot estimate reliably the OA volatility distribution, leading to large uncertainties, since there are many different combinations of the three properties that can lead to similar thermograms. We propose an improved experimental approach combining TD and isothermal dilution measurements. We evaluate this experimental approach using the same model, and show that it is suitable for studies of OA volatility in the lab and the field.

scholarly journals Measuring the atmospheric organic aerosol volatility distribution: a theoretical analysis

2014 ◽  
Vol 7 (1) ◽  
pp. 859-893 ◽  
Author(s):  
E. Karnezi ◽  
I. Riipinen ◽  
S. N. Pandis
Keyword(s):  
Experimental Approach ◽  
Organic Aerosol ◽  
Accommodation Coefficient ◽  
Vaporization Enthalpy ◽  
Typical Result ◽  
Volatile Components ◽  
Particulate Phase ◽  
Aerosol Mass ◽  
Mass Accommodation Coefficient ◽  
Atmospheric Concentrations

Abstract. Organic compounds represent a significant fraction of submicrometer atmospheric aerosol mass. Even if most of these compounds are semi-volatile in atmospheric concentrations, the ambient organic aerosol volatility is quite uncertain. The most common volatility measurement method relies on the use of a thermodenuder (TD). The aerosol passes through a heated tube where its more volatile components evaporate leaving the less volatile behind in the particulate phase. The typical result of a~thermodenuder measurement is the mass fraction remaining (MFR), which depends among other factors on the organic aerosol (OA) vaporization enthalpy and the accommodation coefficient. We use a new method combining forward modeling, introduction of "experimental" error and inverse modeling with error minimization for the interpretation of TD measurements. The OA volatility distribution, its effective vaporization enthalpy, the mass accommodation coefficient and the corresponding uncertainty ranges are calculated. Our results indicate that existing TD-based approaches quite often cannot estimate reliably the OA volatility distribution, leading to large uncertainties, since there are many different combinations of the three properties that can lead to similar thermograms. We propose an improved experimental approach combining TD and isothermal dilution measurements. We evaluate this experimental approach using the same model and show that it is suitable for studies of OA volatility in the lab and the field.

scholarly journals Effect of organic compounds on nanoparticle formation in diluted diesel exhaust

2004 ◽  
Vol 4 (3) ◽  
pp. 609-620 ◽  
Author(s):  
U. Mathis ◽  
M. Mohr ◽  
R. Zenobi
Keyword(s):  
Organic Compounds ◽  
Methyl Tert Butyl Ether ◽  
Scanning Mobility Particle Sizer ◽  
Butyl Ether ◽  
Nucleation Mode ◽  
Particle Sampling ◽  
Wide Range ◽  
Volatile Organic ◽  
Particle Sizer ◽  
Diesel Vehicle

Abstract. The nucleation of nanoparticles in the exhaust of a modern light-duty diesel vehicle was investigated on a chassis dynamometer. This laboratory study is focused on the influence of volatile organic compounds (VOCs) on nucleation of volatile nanoparticles. Different organic compounds were added to the dilution air of the particle sampling under different sampling conditions. Sample temperature and relative sample humidity were varied in a wide range. The number size distribution of the particles was measured with a scanning mobility particle sizer (SMPS) and showed significant differences in response to the added organic compounds. While the nucleation mode particles showed a large variation in concentration, the accumulation mode particles remained unchanged for all compounds. Depending on the functional group, organic compounds were capable of initiating and increasing (alcohols and toluene) or decreasing (acetone, aniline, and methyl tert-butyl ether (MTBE)) nucleation mode particles. Short volatile aliphatic hydrocarbons (hexane and cyclohexane) turned out to be without effect on nucleation of nanoparticles. Possible reasons for the differences are discussed.

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