Measurement and analysis of atmospheric concentrations of isoprene and its reaction products in central Texas

Isomer-Selective Study of the OH-Initiated Oxidation of Isoprene in the Presence of O2 and NO: 2. The Major OH Addition Channel

“…46 Work by Deng et al 47 and Blitz et al 48 also supports adopting a pressure-independent rate constant of 3.0 × we have employed similar oxygen concentrations in our experiments to ensure maximum sensitivity to this rate constant in our simulations. The addition of either O 2 or NO to the hydroxyalkyl radical represents a competition between radical chain propagation (k 4 + k 5 + k 6 ) and chain termination (k 3 ), and it is the relative magnitude of these two rates, that is, k 3 [NO] and (k 4 …”

“…[22][23][24] Theoretical studies suggest that decomposition is the sole fate for the -hydroxyalkoxy radicals [25][26][27] leading to the formation of methylvinyl ketone, methacrolein, and formaldehyde as firstgeneration end products. [28][29][30][31][32][33][34] The δ-hydroxyalkoxy radicals however, undergo prompt 1,5 hydrogen shift 35,36 followed by hydrogen abstraction or reaction with O 2 to form C 5 or C 4 hydroxycarbonyl compounds. 37 Hydrogen abstraction by O 2 during the oxidation process generates HO 2 , which reacts with NO to regenerate OH radicals.…”

Seasonal, diurnal and nocturnal variations of carbonyl compounds in the semi-urban environment of Orléans, France

“…To evaluate their influence on human health as well as atmospheric chemistry, field measurements of atmospheric carbonyls have been carried out in different areas, including urban (Cheng et al 2014;Lü et al 2010;Weng et al 2009;Pang and Mu 2006;Pang and Lee 2010;Xu et al 2010;Zhang et al 2012;Feng et al 2005;Ho et al 2002;Nguyen et al 2001;Possanzini et al 2002), rural (Xie et al 2008;Villanueva-Fierro et al, 2004;Wiedinmyer et al 2001;Solberg et al 2001;Shepson et al 1991;Cheng et al 2014) and remote areas (Singh et al 2004;Zhou and Mopper 1993;Wagner et al 2001;De Serves 1994). In comparison with urban areas, however, investigations on atmospheric carbonyls in rural or semi-urban areas are still sparse.…”

Seasonal and Diurnal Characteristics of Carbonyls in Urban Air in Qinzhou, China

“…They are the sources of free radicals and organic aerosols, as well as the precursors of organic acids and oxidants, including ozone (O 3 ) and peroxycarboxylic nitric anhydrides (Carlier et al, 1986;Roberts, 1990;Atkinson, 2000). Carbonyls are emitted into the atmosphere from primary anthropogenic (Kean et al, 2001;Kim et al, 2008) and biogenic sources (Seco et al, 2007;Guo et al, 2009), or formed as reaction intermediates from the oxidations of hydrocarbons (Wiedinmyer et al, 2001;Duane et al, 2002;Guo et al, 2013).…”

“…Studies have been performed to evaluate carbonyls' levels and sources (Kean et al, 2001;Seco et al, 2007;Pal et al, 2008), distributions (Moussa et al, 2006;Cerón et al, 2007;Pang et al, 2009), photochemical formations (Wiedinmyer et al, 2001;Duane et al, 2002;Guo et al, 2013), health risks (Cavalcante et al, 2006;Noisel et al, 2007;Weng et al, 2009), and analytical approaches (Guo et al, 2007;Kim and Pal, 2010;Ho et al, 2011;Pang et al, 2011;Saha et al, 2012;Xie et al, 2013). However in China, investigation on carbonyls in developing regions (e.g., in Guangxi) is very limited due to the poor economic capabilities compared to economically developed regions (Feng et al, 2005;Duan et al, 2008;Lü et al, 2010;Guo et al, 2011;Zhang et al, 2012), resulting in that our current knowledge of carbonyls remains weak in these developing regions.…”