). The formation of oligomers requires binding sites for the interaction of two molecules. The presence of two double bonds in limonene allows the formation of binding sites at opposite ends of the molecule, while for α-pinene oxidation products this can happen at only one reaction site.
, which inferred a high oligomer content of limonene SOA and a low oligomer content of α-pinene SOA based on thermal evaporation rates.
In addition, using linear combinations of mass spectra, we show that the molecular-level details provided by FIGAERO-CIMS clearly elucidate changes in SOA chemical composition between single- and multi-precursor experiments, whereas the same analyses with AMS mass spectra yields no evidence for differing SOA composition in the SEQ and MIX experiments. This is potentially due to non-linearity in the SOA formation being driven by the efficient formation of hetero-oligomers.
SOA mass yield is not a scalar value, but rather strongly depends on the organic mass present in the system (