Environmental chamber study on liquid phase oxidation of isoprene

With global emissions of ∼600 Tg yr^-1 isoprene contributes the largest fraction to biogenic non-methane hydrocarbons in the atmosphere. The estimated resulting secondary organic aerosol mass from isoprene by gas phase oxidation, ∼6-30 Tg yr^-1, is relatively small. Recent field studies suggest the importance of additional pathways, like aqueous phase oxidation of isoprene, hence increasing the aerosol mass yields. To investigate into the liquid phase chemistry of isoprene and its oxidation products we conducted an extensive laboratory study using the Harvard Environmental Chamber. Different gas and particle phase instruments were used to monitor changes in gas phase composition, particle number, size distribution and chemical composition. Liquid chromatography coupled with UV detection was used to identify known first and second generation oxidation products of isoprene, like methyl vinyl ketone and glyoxal. Another point of interest here is the study of oligomerization reactions from these precursors within the liquid phase.