Fig. 1.
Effect of low oxygen level and OH scavenger (propane, C3H8, or hydrogen, H2) on ELVOC production during oxidation of (A) limonene and (B) myrcene. During low-oxygen experiments, ELVOC formation is significantly suppressed as O2 addition to the intermediate reaction products becomes slower. During limonene oxidation, only a few ELVOC species are affected by OH scavenging, illustrating that ozonolysis is the main pathway for ELVOC formation in our experiment. In the case of myrcene, a clear decrease in total ELVOC was observed upon OH scavenging, demonstrating the role of OH oxidation in the ELVOC formation pathway. C10H16O7 and C10H14O7 are identified as dimers from small ozonolysis-produced RO2 radicals.