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Updated: Jun 17, 2026

Production and Measurement of Organic Particulate Matter in a Flow Tube Reactor
Published on: December 15, 2018
A semiempirical correlation between enthalpy of vaporization and saturation concentration for organic aerosol
Scott A Epstein1, Ilona Riipinen, Neil M Donahue
1Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Abstract:
To model the temperature-induced partitioning of semivolatile organics in laboratory experiments or atmospheric models, one must know the appropriate heats of vaporization. Current treatments typically assume a constant value of the heat of vaporization or else use specific values from a small set of surrogate compounds. With published experimental vapor-pressure data from over 800 organic compounds, we have developed a semiempirical correlation between the saturation concentration (C*, microg m(-3)) and the heat of vaporization (deltaH(VAP), kJ mol(-1)) for organics in the volatility basis set. Near room temperature, deltaH(VAP) = -11 log(10)C(300)(*) + 129. Knowledge of the relationship between C* and deltaH(VAP) constrains a free parameter in thermodenuder data analysis. A thermodenuder model using our deltaH(VAP) values agrees well with thermal behavior observed in laboratory experiments.
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