Volatility parameters of secondary organic aerosol components determined using a thermal denuder

In this study, the characterization of a new thermal denuder and its application to determine the volatility parameters of important components of secondary organic aerosol (SOA) are presented in detail. The temperature ramping rate to achieve a set value was ~14.3 °C min⁻¹ in the range of 25–150 °C. Particle loss during the penetration through the denuder was negligible in the temperature and effective residence time (RT) ranges of 25 °C–60 °C and 12.5 s–50 s, respectively. In addition, a vapor-phase aerosol reached equilibrium with the gas phase at an effective RT of approximately 24 s. Furthermore, volatility profile data generated using the thermal denuder with the help of a scanning particle sizer were used to determine the saturation pressure (P⁰_sat) at 25 °C and enthalpy of vaporization (ΔH_v) of typical biogenic and anthropogenic SOA components by the integrated volume method. Determined ΔH_v and P⁰_sat values for succinic acid, adipic acid, pimelic acid, phthalic acid, pinic acid, and ketopinic acid were 86.6 ± 2.5 kJ mol⁻¹, 146.1 kJ mol⁻¹, 139.2 kJ mol⁻¹, 135.9 kJ mol⁻¹, 93.8 ± 1.8 kJ mol⁻¹, and 136.6 kJ mol⁻¹ and 4.70 ± 0.7 x 10⁻⁵ Pa, 1.98 x 10⁻⁵ Pa, 8.91 x 10⁻⁵ Pa, 8.50 x 10⁻⁵ Pa, 1.61 ± 0.5 x 10⁻⁴ Pa, and 5.81 x 10⁻⁵ Pa, respectively. These values were comparable with the literature data.