Multifunctional Products of Isoprene Oxidation in Polluted Atmosphere and Their Contribution to SOA

Isoprene (2-methyl-1, 3-butadiene) is a nonmethane volatile organic compound (VOC) with the largest global emission and high reactivity. The oxidation of isoprene is crucial to atmospheric photochemistry and contributes significantly to the global formation of secondary organic aerosol. Here, we conducted comprehensive observations in polluted megacities of Nanjing and Shanghai during summer of 2018. We identified multiple functionalized isoprene oxidation products, of which 72% and 88% of the total mole concentration were nitrogen-containing species with the dominant compound being C5 dihydroxyl dinitrate (C5H10N2O8). We calculated the volatility using the group-contribution method and estimated the particle-phase concentration by equilibrium gas/particle partitioning. The results showed that the multifunctional products derived from isoprene oxidation can contribute to 2.6% of the total organic aerosol mass (0.28 +/- 0.27 mu g/m(3)), highlighting the potential importance of isoprene oxidation in polluted regions.

Automated summary

The study revealed that the oxidation products of isoprene play a significant role in the formation of global secondary organic aerosols, particularly in heavily polluted cities like Nanjing and Shanghai. The multifunctional products derived from isoprene oxidation contribute to a notable percentage of total organic aerosol mass, emphasizing the potential importance of isoprene oxidation in polluted regions.