Measured Solid State and Sub-Cooled Liquid Vapour Pressures of Benzaldehydes Using Knudsen Effusion Mass Spectrometry

Benzaldehydes are components of atmospheric aerosol that poorly represented in current vapour pressure predictive techniques. In this study the solid state (PSsat) and sub-cooled liquid saturation pressures (PLsat) were measured over a range temperatures (298–328 K) for chemically diverse group benzaldehydes. The selected benzaldehydes allowed effects varied geometric isomers functionalities on (Psat) to be probed. PSsat was using Knudsen effusion mass spectrometry (KEMS) PLsat obtained via correction utilising experimental enthalpy fusion melting point values differential scanning calorimetry (DSC). strength hydrogen bond (H-bond) most important factor determining when H-bond present polarisability compound not present. Typically compounds capable bonding had 1 2 orders magnitude lower than those could H-bond. compared estimated three different techniques (Nannoolal et al. method, Myrdal Yalkowsky SIMPOL). Nannoolal method require use boiling predict Psat. For showed best performance. All less an order error average, however more significant errors within these methods. Such will have implications studies trying ascertain role growth human health impacts. SIMPOL predicted closest experimentally determined values.