Impact of Humidity on the Ozone Initiated Oxidation of Limonene, Δ3-Carene, and α-Pinene

Authors:
Publisher website
Google Scholar
Abstract
The effect of water on the initial secondary organic aerosol (SOA) formation from gas-phase ozonolysis of limonene, Δ3-carene, and α-pinene (∼3 and ∼1.5 × 1011 molecule cm-3 reacted) has been investigated in a flow reactor at controlled relative humidity (RH), temperature (298 ± 0.4 K), and reaction time (270 ± 2 s). Low amounts of terpene converted minimize the impact of secondary reactions. A comparison of the SOA formation from the three terpenes was made for initial rate of reactions being around 7.5 × 108 and 15 × 108 molecule cm-3 s-1. The most efficient species in producing SOA was limonene, while α-pinene was the least efficient. The results showed that an enhancement in water vapor concentration (M10-300nm) and total number (N10-300nm). The effect on number and mass were a factor of 2−3 and 4−8, respectively. Physical water up-take can partly explain the increase in mass, but not the observed increase in number. Therefore it was concluded that the increase in water concentration must, by a gas-phase reaction, produce more low volatility product(s).

This publication has 33 references indexed in Scilit: