Determining how levoglucosan partitions between gas and particle phases Investigating temperature effects in the presence of ammonium sulphate aerosols

Abstract

Air pollution is a major environmental concern and affects millions of people worldwide. Biomass burning is a common practice which contributes emissions to the atmosphere, which reduce air quality. Levoglucosan is created from cellulose at high temperatures and is the most abundant pollutant from biomass burning. It contributes to the formation of primary organic aerosols and secondary aerosols since it is a semi-volatile organic compound subject to gas-to-particle partitioning. This study investigated levoglucosan's partitioning behaviour at four different temperatures (0, 10, 20, and 40 °C) in the presence of ammonium sulphate. A filter inlet for gases and aerosols, combined with a time-of-flight chemical mass spectrometer was used alongside a scanning mobility particle sizer. The results demonstrated a clear temperature dependence, with a decreasing gas-to-particle ratio observed as temperature increased. However, the enthalpy of vaporisation of 31 kJ mol-1 was lower than literature values. This was likely caused by vapour wall losses. Despite this uncertainty, the method is advantageous as it can be used to study aerosol mixtures rather than focusing on a singular compound.