Origin of secondary fatty alcohols in aerosols based on the particle size distributions and chemical analysis of plant leaves in a cool-temperate forest

Abstract

Fatty alcohols (FAs) are major components of surface lipids in plant leaves and serve as surface-active organic aerosols, which can act as primary biological aerosol particles. This study aims to elucidate the specific plant species as a dominant source of secondary FAs (SFAs) in aerosols, based on simultaneous samplings of size-segregated aerosols and plant leaves at Tomakomai experimental forest in different seasons. Among five SFAs identified, n-nonacosan-10-ol was the most abundant compound in aerosols. The concentrations of n-nonacosan-10-ol were the highest in spring, with its peak diameter > 7.2 micrometer. n-nonacosan-10-ol was also identified in the needle leaf samples of Abies sachalinensis (conifer), mainly in the non-esterified form. The overall results suggest that plant waxes in the needle leaves can act as source of aerosol SFAs, and that the emission strength is controlled by the phenology of the leaf and the local wind speeds.