EVAPORATION: a new vapor pressure estimation method for organic molecules  including non-additivity and intramolecular interactions

Abstract. We present EVAPORATION (Estimation of VApour Pressure of ORganics, Accounting for Temperature, Intramolecular, and Non-additivity effects), a method to predict vapour pressure p0 of organic molecules needing only molecular structure as input. The method is applicable to zero-, mono- and polyfunctional molecules. A simple formula to describe log10p0(T) is employed, that takes into account both a wide temperature dependence and the non-additivity of functional groups. In order to match the recent data on functionalised diacids an empirical modification to the method was introduced. Contributions due to carbon skeleton, functional groups, and intramolecular interaction between groups are included. Molecules typically originating from oxidation of biogenic molecules are within the scope of this method: carbonyls, alcohols, ethers, esters, nitrates, acids, peroxides, hydroperoxides, peroxy acyl nitrates and peracids. Therefore the method is especially suited to describe compounds forming secondary organic aerosol (SOA).

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EVAPORATION: a new vapour pressure estimation methodfor organic molecules including non-additivity and intramolecular interactions

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-9431-2011 ◽

2011 ◽

Vol 11 (18) ◽

pp. 9431-9450 ◽

Cited By ~ 116

Author(s):

S. Compernolle ◽

K. Ceulemans ◽

J.-F. Müller

Keyword(s):

Molecular Structure ◽

Functional Groups ◽

Vapour Pressure ◽

Simple Formula ◽

Organic Molecules ◽

Intramolecular Interaction ◽

Organic Aerosol ◽

Intramolecular Interactions ◽

Pure Compound ◽

Subcooled Liquid

Abstract. We present EVAPORATION (Estimation of VApour Pressure of ORganics, Accounting for Temperature, Intramolecular, and Non-additivity effects), a method to predict (subcooled) liquid pure compound vapour pressure p0 of organic molecules that requires only molecular structure as input. The method is applicable to zero-, mono- and polyfunctional molecules. A simple formula to describe log10p0(T) is employed, that takes into account both a wide temperature dependence and the non-additivity of functional groups. In order to match the recent data on functionalised diacids an empirical modification to the method was introduced. Contributions due to carbon skeleton, functional groups, and intramolecular interaction between groups are included. Molecules typically originating from oxidation of biogenic molecules are within the scope of this method: aldehydes, ketones, alcohols, ethers, esters, nitrates, acids, peroxides, hydroperoxides, peroxy acyl nitrates and peracids. Therefore the method is especially suited to describe compounds forming secondary organic aerosol (SOA).

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Estimating fusion properties for functionalised acids

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-8385-2011 ◽

2011 ◽

Vol 11 (16) ◽

pp. 8385-8394 ◽

Cited By ~ 6

Author(s):

S. Compernolle ◽

K. Ceulemans ◽

J.-F. Müller

Keyword(s):

Vapour Pressure ◽

Estimation Error ◽

Estimation Method ◽

Organic Aerosol ◽

Estimation Methods ◽

Fusion Temperature ◽

Subcooled Liquid ◽

Fusion Data ◽

Simple Estimation ◽

Data Estimation

Abstract. Multicomponent organic aerosol (OA) is likely to be liquid, or partially liquid. Hence, to describe the partitioning of these components, their liquid vapour pressure is desired. Functionalised acids (e.g. diacids) can be a significant part of OA. But often measurements are available only for solid state vapour pressure, which can differ by orders of magnitude from their liquid counterparts. To convert such a sublimation pressure to a subcooled liquid vapour pressure, fusion properties (two out of these three quantities: fusion enthalpy, fusion entropy, fusion temperature) are required. Unfortunately, experimental knowledge of fusion properties is sometimes missing in part or completely, hence an estimation method is required. Several fusion data estimation methods are tested here against experimental data of functionalised acids, and a simple estimation method is developed, specifically for this family of compounds, with a significantly smaller estimation error than the literature methods.

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Technical Note: Vapor pressure estimation methods applied to secondary organic aerosol constituents from α-pinene oxidation: an intercomparison study

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-6271-2010 ◽

2010 ◽

Vol 10 (13) ◽

pp. 6271-6282 ◽

Cited By ~ 32

Author(s):

S. Compernolle ◽

K. Ceulemans ◽

J.-F. Müller

Keyword(s):

Vapor Pressure ◽

Functional Groups ◽

State Of The Art ◽

Organic Aerosol ◽

Technical Note ◽

Estimation Methods ◽

Vapor Pressures ◽

Aerosol Formation ◽

Pressure Estimation ◽

Intercomparison Study

Abstract. We applied and compared seven vapor pressure estimation methods to the condensable compounds generated in the oxidation of α-pinene, as described by the state-of-the-art mechanism of the BOREAM model Capouet et al., 2008. Several of these methods had to be extended in order to treat functional groups such as hydroperoxides and peroxy acyl nitrates. Large differences in the estimated vapor pressures are reported, which will inevitably lead to large differences in aerosol formation simulations. Cautioning remarks are given for some vapor pressure estimation methods.

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Explicit modelling of SOA formation from α-pinene photooxidation: sensitivity to vapour pressure estimation

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-10121-2011 ◽

2011 ◽

Vol 11 (3) ◽

pp. 10121-10158 ◽

Cited By ~ 2

Author(s):

R. Valorso ◽

B. Aumont ◽

M. Camredon ◽

T. Raventos-Duran ◽

C. Mouchel-Vallon ◽

...

Keyword(s):

Organic Compounds ◽

Vapour Pressure ◽

Estimation Method ◽

Organic Aerosol ◽

Reaction Scheme ◽

Oxidation Products ◽

Organic Species ◽

Structure Activity ◽

Volatile Organic ◽

Kinetics Of

Abstract. The sensitivity of the formation of secondary organic aerosol (SOA) to the estimated vapour pressures of the condensable oxidation products is explored. A highly detailed reaction scheme was generated for α-pinene photooxidation using the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A). Vapour pressures (Pvap) were estimated with three commonly used structure activity relationships. The values of Pvap were compared for the set of secondary species generated by GECKO-A to describe α-pinene oxidation. Discrepancies in the predicted vapour pressures were found to increase with the number of functional groups borne by the species. For semi-volatile organic compounds (i.e. organic species of interest for SOA formation), differences in the predicted Pvap range between a factor of 5 to 200 in average. The simulated SOA concentrations were compared to SOA observations in the Caltech chamber during three experiments performed under a range of NOx conditions. While the model captures the qualitative features of SOA formation for the chamber experiments, SOA concentrations are systematically overestimated. For the conditions simulated, the modelled SOA speciation appears to be rather insensitive to the Pvap estimation method.

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Novel methods for predicting gas–particle partitioning during the formation of secondary organic aerosol

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-13189-2014 ◽

2014 ◽

Vol 14 (23) ◽

pp. 13189-13204 ◽

Cited By ~ 17

Author(s):

F. Wania ◽

Y. D. Lei ◽

C. Wang ◽

J. P. D. Abbatt ◽

K.-U. Goss

Keyword(s):

Functional Groups ◽

Vapour Pressure ◽

Secondary Organic Aerosol ◽

Prediction Method ◽

Organic Aerosol ◽

Estimation Methods ◽

Minor Effect ◽

Normal Alkanes ◽

Sorption Data ◽

Order Of Magnitude

Abstract. Several methods have been presented in the literature to predict an organic chemical's equilibrium partitioning between the water insoluble organic matter (WIOM) component of aerosol and the gas phase, Ki,WIOM, as a function of temperature. They include (i) polyparameter linear free energy relationships calibrated with empirical aerosol sorption data, as well as (ii) the solvation models implemented in SPARC and (iii) the quantum-chemical software COSMOtherm, which predict solvation equilibria from molecular structure alone. We demonstrate that these methods can be used to predict Ki,WIOM for large numbers of individual molecules implicated in secondary organic aerosol (SOA) formation, including those with multiple functional groups. Although very different in their theoretical foundations, these methods give remarkably consistent results for the products of the reaction of normal alkanes with OH, i.e. their partition coefficients Ki,WIOM generally agree within one order of magnitude over a range of more than ten orders of magnitude. This level of agreement is much better than that achieved by different vapour pressure estimation methods that are more commonly used in the SOA community. Also, in contrast to the agreement between vapour pressure estimates, the agreement between the Ki,WIOM estimates does not deteriorate with increasing number of functional groups. Furthermore, these partitioning coefficients Ki,WIOM predicted SOA mass yields in agreement with those measured in chamber experiments of the oxidation of normal alkanes. If a Ki,WIOM prediction method was based on one or more surrogate molecules representing the solvation properties of the mixed OM phase of SOA, the choice of those molecule(s) was found to have a relatively minor effect on the predicted Ki,WIOM, as long as the molecule(s) are not very polar. This suggests that a single surrogate molecule, such as 1-octanol or a hypothetical SOA structure proposed by Kalberer et al. (2004), may often be sufficient to represent the WIOM component of the SOA phase, greatly simplifying the prediction. The presented methods could substitute for vapour-pressure-based methods in studies such as the explicit modelling of SOA formation from single precursor molecules in chamber experiments.

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Technical note: Vapor pressure estimation methods applied to secondary organic aerosol constituents from α-pinene oxidation: an intercomparison study

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-8487-2010 ◽

2010 ◽

Vol 10 (4) ◽

pp. 8487-8513 ◽

Cited By ~ 2

Author(s):

S. Compernolle ◽

K. Ceulemans ◽

J.-F. Müller

Keyword(s):

Vapor Pressure ◽

Functional Groups ◽

State Of The Art ◽

Organic Aerosol ◽

Technical Note ◽

Estimation Methods ◽

Vapor Pressures ◽

Aerosol Formation ◽

Pressure Estimation ◽

Intercomparison Study

Abstract. We applied and compared seven vapor pressure estimation methods to the condensable compounds generated in the oxidation of α-pinene, as described by the state-of-the-art mechanism of the BOREAM model (Capouet et al., 2008). Several of these methods had to be extended in order to treat functional groups such as hydroperoxides and peroxy acyl nitrates. Large differences in the estimated vapor pressures are reported, which will inevitably lead to large differences in aerosol formation simulations. Cautioning remarks are given for some vapor pressure estimation methods.

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On the detection of oxidized and highly oxidized organic molecules by CHARON PTR-MS via ammonium adduct ionization

10.5194/egusphere-egu2020-4471 ◽

2020 ◽

Author(s):

Markus Müller ◽

Felix Piel ◽

Armin Wisthaler

Keyword(s):

Mass Spectrometry ◽

Functional Groups ◽

Organic Molecules ◽

Organic Aerosol ◽

Proton Transfer Reaction ◽

Protonated Form ◽

Ionization Mass ◽

Single Digit ◽

Target Analytes ◽

Ammonium Adduct

Oxidized and highly oxidized organic molecules are important target analytes in atmospheric air samples. In recent years, several chemical ionization mass spectrometry (CIMS) methods have been developed for detecting these target analytes in real time and at ultra-trace levels. One of these CIMS techniques is proton-transfer-reaction mass spectrometry (PTR-MS), which, in combination with the so-called CHARON inlet, measures oxidized and highly oxidized organic molecules in the atmosphere in the gaseous and particulate state. PTR-MS typically uses hydronium ions (H3O+) as reagent ions for detecting organic analytes in their protonated form, [A+H+]. H3O+ ions react with all oxidized organics at unit efficiency, meaning that PTR-MS universally detects these target analytes, with little dependency of the signal response on their oxidation state. A drawback of PTR-MS operation in the H3O+ mode is that oxidized functional groups are often ejected upon protonation.Herein, we present the results obtained when a CHARON PTR-MS analyzer was operated with ammonium (NH4+) ions as CI reagent ions. We studied the instrumental response to a set of oxidized and highly oxidized compounds including hydroxy, carboxy and peroxy functional groups. We found that fragmentation was greatly suppressed, with ammonium adducts, [A+NH4]+, being the main analyte ions formed. The ionization efficiency ranged from 10 to 80% of the collisional limit, meaning that the NH4+ mode is less quantitative than the H3O+ mode. The performance and advantages of ammonium adduct ionization are demonstrated on two application examples: i) secondary organic aerosol generated in the laboratory from the ozonolysis of limonene, with a particular focus on the detection of peroxides and dimers, and (ii) ambient organic aerosol in Innsbruck, Austria, which was characterized at the molecular level at single digit ng m-&#179; mass concentrations.

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Uncertain Henry's Law Constants Compromise Equilibrium Partitioning Calculations of Atmospheric Oxidation Products

10.5194/acp-2017-92 ◽

2017 ◽

Cited By ~ 1

Author(s):

Chen Wang ◽

Tiange Yuan ◽

Stephen A. Wood ◽

Kai-Uwe Goss ◽

Jingyi Li ◽

...

Keyword(s):

Functional Groups ◽

Organic Compounds ◽

Estimation Method ◽

Intramolecular Interactions ◽

The Other ◽

Oxidation Products ◽

Chemical Mechanism ◽

Phase Partitioning ◽

Wide Range ◽

Partitioning Coefficients

Abstract. Gas-particle partitioning governs the distribution, removal and transport of organic compounds in the atmosphere and the formation of secondary organic aerosol. The large variety of atmospheric species and their wide range of properties make predicting this partitioning equilibrium challenging. Here we expand on earlier work and predict gas-organic and gas-aqueous phase partitioning coefficients for 3414 atmospherically relevant molecules using COSMOtherm, SPARC and poly-parameter linear free energy relationships. The Master Chemical Mechanism generated the structures by oxidizing primary emitted volatile organic compounds. Predictions for gas-organic phase partitioning coefficients (KWIOM/G) by different methods are on average within one order of magnitude of each other, irrespective of the numbers of functional groups, except for predictions by COSMOtherm and SPARC for compounds with more than three functional groups, which have a slightly higher discrepancy. Discrepancies between predictions of gas-aqueous partitioning (KW/G) are much larger and increase with the number of functional groups in the molecule. In particular, COSMOtherm often predicts much lower KW/G for highly functionalized compounds than the other methods. While the quantum-chemistry based COSMOtherm accounts for the influence of intramolecular interactions on conformation, highly functionalized molecules likely fall outside of the applicability domain of the other techniques, which at least in part rely on empirical data for calibration. Further analysis suggests that atmospheric phase distribution calculations are sensitive to the partitioning coefficient estimation method, in particular to the estimated value of KW/G. The large uncertainty in KW/G predictions for highly functionalized organic compounds needs to be resolved to improve the quantitative treatment of SOA formation.

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Explicit modelling of SOA formation from α-pinene photooxidation: sensitivity to vapour pressure estimation

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-6895-2011 ◽

2011 ◽

Vol 11 (14) ◽

pp. 6895-6910 ◽

Cited By ~ 86

Author(s):

R. Valorso ◽

B. Aumont ◽

M. Camredon ◽

T. Raventos-Duran ◽

C. Mouchel-Vallon ◽

...

Keyword(s):

Organic Compounds ◽

Vapour Pressure ◽

Estimation Method ◽

Organic Aerosol ◽

Reaction Scheme ◽

Oxidation Products ◽

Organic Species ◽

Structure Activity ◽

Volatile Organic ◽

Kinetics Of

Abstract. The sensitivity of the formation of secondary organic aerosol (SOA) to the estimated vapour pressures of the condensable oxidation products is explored. A highly detailed reaction scheme was generated for α-pinene photooxidation using the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A). Vapour pressures (Pvap) were estimated with three commonly used structure activity relationships. The values of Pvap were compared for the set of secondary species generated by GECKO-A to describe α-pinene oxidation. Discrepancies in the predicted vapour pressures were found to increase with the number of functional groups borne by the species. For semi-volatile organic compounds (i.e. organic species of interest for SOA formation), differences in the predicted Pvap range between a factor of 5 to 200 on average. The simulated SOA concentrations were compared to SOA observations in the Caltech chamber during three experiments performed under a range of NOx conditions. While the model captures the qualitative features of SOA formation for the chamber experiments, SOA concentrations are systematically overestimated. For the conditions simulated, the modelled SOA speciation appears to be rather insensitive to the Pvap estimation method.

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Novel methods for predicting gas-particle partitioning during the formation of secondary organic aerosol

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-21341-2014 ◽

2014 ◽

Vol 14 (15) ◽

pp. 21341-21385 ◽

Cited By ~ 2

Author(s):

F. Wania ◽

Y. D. Lei ◽

C. Wang ◽

J. P. D. Abbatt ◽

K.-U. Goss

Keyword(s):

Functional Groups ◽

Vapour Pressure ◽

Secondary Organic Aerosol ◽

Organic Aerosol ◽

Basis Sets ◽

Estimation Methods ◽

Minor Effect ◽

Normal Alkanes ◽

Sorption Data ◽

Better Than

Abstract. Several methods have been presented in the literature to predict an organic chemical's equilibrium partitioning between the water insoluble organic matter (WIOM) component of aerosol and the gas phase, Ki, WIOM as a function of temperature. They include (i) polyparameter linear free energy relationships calibrated with empirical aerosol sorption data, as well as (ii) the solvation models implemented in SPARC and (iii) the quantum-chemical software Cosmotherm, which predict solvation equilibria from molecular structure alone. We demonstrate that these methods can be used to predict Ki, WIOM for large numbers of individual molecules implicated in secondary organic aerosol (SOA) formation, including those with multiple functional groups. Although very different in their theoretical foundations, these methods give remarkably consistent results for the products of the reaction of normal alkanes with OH, i.e. their partition coefficients Ki, WIOM generally agree within one order of magnitude over a range of more than ten orders of magnitude. This level of agreement is much better than that achieved by different vapour pressure estimation methods that are more commonly used in the SOA community. Also, in contrast to the agreement between vapour pressure estimates, that between the Ki, WIOM estimates does not deteriorate with increasing number of functional groups. Furthermore, these partitioning coefficients Ki, WIOM are found to predict the SOA mass yield in chamber experiments of the oxidation of normal alkanes as good or better than a vapour pressure based method. If a Ki, WIOM prediction method was based on one or more surrogate molecules representing the solvation properties of the mixed OM phase of SOA, the choice of those molecule(s) was found to have a relatively minor effect on the predicted Ki, WIOM, as long as the molecule(s) are not very polar. This suggests that a single surrogate molecule, such as 1-octanol or a hypothetical SOA structure proposed by Kalberer et al. (2004), may often be sufficient to represent the WIOM component of the SOA phase, greatly simplifying the prediction. The presented methods could substitute for vapour pressure based methods in studies such as the explicit modeling of SOA formation from single precursor molecules in chamber experiments or the assignment of SOA-forming molecules to volatility basis sets.

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