Molecular size evolution of oligomers in organic aerosols collected in urban atmospheres and generated in a smog chamber.

摘要: Only a minor fraction of the total organic aerosol mass can be resolved on molecular level. High weight compounds in aerosols have recently gained much attention because this class compound potentially explains major unexplained mass. These been identified with different spectrometric methods, and masses up to 1000 Da are found secondary (SOA) generated from aromatic terpene precursors smog chamber experiments. Here, we apply matrix-assisted laser desorption/ionization spectrometry (MALDI−MS) SOA particles two biogenic precursors, α-pinene isoprene. Similar oligomer patterns these systems, but also trimethylbenzene, an anthropogenic precursor. However, maxima sizes were measured for three systems. While oligomers isoprene mostly below 600−700 Da, they grow about 1...