Reactions of ozone with α‐pinene and β‐pinene in air: Yields of gaseous and particulate products

Abstract

Reactions of ozone with α‐pinene and β‐pinene were studied for the purpose of obtaining the quantitative yields of gaseous and particulate products. Major gaseous products from α‐pinene were CO, CO2, HCHO, and aldehydes mainly composed of pinonaldehyde and nor‐pinonaldehyde, while those from β‐pinene were CO2, HCHO, and 6,6‐dimethylbicyclo[3.1.1]heptan‐2‐one. Average molar yields from α‐pinene were CO; 9±1%, CO2; 30±2%, HCHO; 22±1%, and aldehydes; 51±6%. Average molar yields from β‐pinene were CO2; 27±2%, HCHO; 76±2%, and 6,6‐dimethylbicyclo[3.1.1]heptan‐2‐one; 40±2%. Particulate products were found to include pinonaldehyde, nor‐pinonaldehyde, pinonic acid, and nor‐pinonic acid from α‐pinene. The yields of the particulate aldehydes decreased with the reaction time, whereas the yields of the acids increased. This observation suggests the sequential oxidation of aldehydes to carboxylic acids. From β‐pinene, only 6,6‐dimethylbicyclo[3.1.1]heptan‐2‐one was identified as a particulate product. For α‐pinene, most of the products are explainable in terms of the reaction mechanism similar to that for the cyclohexene/ozone reaction, whereas for β‐pinene the principal reaction path is that of the doubly substituted Criegee intermediate. The total yields of organic aerosols from both α‐ and β‐pinene were measured with their concentrations at a lower ppb level. The yields were found almost constant in a pinene concentration range from 10 up to 100 ppb, being 18.3±1.1 and 13.8±0.8% for α‐ and β‐pinene, respectively, which are much lower than the previously reported values.

Elemental composition and clustering behaviour of α-pinene oxidation products for different oxidation conditions

“…3.3. Both gas phase and particulate α-pinene oxidation products have been investigated, and more detailed chemical analyses have become available as analytical methods have progressed recently (Hatakeyama et al, 1989;Kamens et al, 1999;Claeys et al, 2009;Eddingsaas et al, 2012a, b;Winkler et al, 2012). Products such as the dicarboxylic acid cis-pinic acid (C 9 H 14 O 4 , Christoffersen et al, 1998), the tricarboxylic acid 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA, C 8 H 12 O 6 , Szmigielski et al, 2007) and oligomeric compounds (Tolocka et al, 2004;Müller et al, 2009) have been identified.…”

The direct and indirect radiative effects of biogenic secondary organic aerosol

“…Kavouras et al, 1999;Yu et al, 1999b;Claeys et al, 2004;Robinson et al, 2011) and in laboratory chamber experiments (e.g. Hatakeyama et al, 1989;Edney et al, 2005;Kroll et al, 2005Kroll et al, , 2006. Over Scandinavia, parcels of air have 448 C. E. Scott et al: The direct and indirect radiative effects of biogenic SOA been found to contain an aerosol mass that is proportional to the length of time the air has spent over forested land (Tunved et al, 2006(Tunved et al, , 2008, suggesting an important contribution to aerosol from BVOC emissions.…”

Generation and Quantification of Ultrafine Particles through Terpene/Ozone Reaction in a Chamber Setting

“…In α-pinene/ozone systems, the main identified reaction products appear to be formaldehyde, acetone, pinonaldehyde, norpinonaldehyde, norpinone, pinonic acid, norpinonic acid, and pinic acid (Hatakeyama et al 1989;Grosjean et al 1992;Jang and Kamens 1999;Yu et al 1998). The reaction 66 A. C. ROHR ET AL.…”