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

Abstract 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 (P0sat) at 25 °C and enthalpy of vaporization (ΔHv) of typical biogenic and anthropogenic SOA components by the integrated volume method. Determined ΔHv and P0sat 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.