Gaseous and Particulate Products from the Atmospheric Ozonolysis of a Biogenic Hydrocarbon, Sabinene

Abstract

Environmental Context. Volatile organic compounds (VOCs) are a source of ozone and secondary organic aerosols, which have significant effects in the lower troposphere and on human health. The emission rate of VOCs from plants exceeds anthropogenic emissions by a factor of ten. In order to understand how these plant-derived compounds influence global ozone budgets, studies into the atmospheric reactions of these compounds are needed. This study investigates the ozonolysis of sabinene, a VOC abundantly emitted by trees in Europe.Abstract. This work investigates both the gaseous and particulate phase products from the ozonolysis of sabinene in smog chamber experiments. The gaseous phase was analyzed in situ by FTIR. The particulate phase was analyzed after sampling with a supercritical fluid extraction technique directly coupled to gas chromatography and mass spectrometry (SFE-GC-MS) and to an in situ derivatization method. Sabinaketone, formaldehyde, and formic acid have been detected in the gaseous phase. More than 30 products have been observed in the secondary organic aerosol formed from sabinene oxidation and among them 10 have been identified as compounds containing carbonyl, hydroxyl and carboxyl groups. Hypotheses concerning reaction formation pathways have been proposed for each identified product in gaseous and particulate phases.

Kinetic and product study of the gas‐phase reaction of sabinaketone with OH radical

“…This method is not without possible artifacts coming from the presence of a number of coproducts during the reaction with OH radicals. In particular, it has been shown that ozonolysis of sabinene produces considerable amount of particles containing sabinaketone [20]. In the case of Alvarado et al, the equilibrium of sabinaketone in both gaseous and particulate phases during the relative rate study could possibly explain the slight difference observed with our study, these artifacts being avoided in our case because of the previous synthesis of sabinaketone.…”

Hydration and Secondary Ozonide of the Criegee Intermediate of Sabinene

“…Although the experimental detection of the products that result from the ozonolysis of sabinene can be difficult, the Fourier-transform infrared (IR) spectrum of the dominant product, sabina ketone, has been reported. ,, The spectrum reported by Chiappini et al is the first to be reported using a synthesized standard. The main absorption band ranges from 1700 to 1800 cm –1 .…”

“…Moreover, another peak with a frequency value of 1158 cm −1 is conformable with the asymmetric vibration of the CO group toward the adjacent CH and CH 2 groups; this is in close agreement with the experimental frequency range of 1100− 1150 cm −1 . 42 2.2. Formation of the SOZ (Pathways A1 and A2).…”

The gas‐phase ozonolysis reaction of methylbutenol: A mechanistic study

“…Such reactions, in addition to hydroxyl‐initiated oxidation of hydrocarbons, lead to the production of various oxygenated organic compounds in the troposphere. Several experimental and theoretical studies circle the fact that during the course of the ozonolysis reactions, the OH radicals are generated …”