Atmospheric Chemistry and Physics
www.atmos-chem-phys.net
1680-7316
1680-7324
7
6
2007
10.5194/acp-7-1565-2007
http://www.atmos-chem-phys.net/7/1565/2007/
http://www.atmos-chem-phys.net/7/1565/2007/acp-7-1565-2007.html
http://www.atmos-chem-phys.net/7/1565/2007/acp-7-1565-2007.pdf
1565
1574
2007-03-22
Daytime tropospheric loss of hexanal and <I>trans</I>-2-hexenal: OH kinetics and UV photolysis
E. Jiménez
B. Lanza
E. Martínez
J. Albaladejo
jose.albaladejo@uclm.es
Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela, s/n. 13071 Ciudad Real, Spain
The ultraviolet (λ=250–370 nm) photolysis and the OH-initiated
oxidation of hexanal and <I>trans</I>-2-hexenal, which are relevant atmospheric
processes, have been investigated at room temperature and as a function of
temperature (T=263–353 K), respectively. This kinetic study as a function
of temperature is reported here for the first time. Absolute absorption
cross sections (σ<sub>λ</sub>) were obtained using a
recently built system operating in the UV region. The obtained σ<sub>λ</sub>
allowed the estimation of the photolysis rates (<I>J</I>) across the
troposphere. Kinetic measurements of the gas-phase reaction of hydroxyl
radicals (OH) with hexanal and <I>trans</I>-2-hexenal were performed by using the
laser pulsed photolysis/laser-induced fluorescence technique. Rate
coefficients <I>k</I><sub>OH</sub> for both aldehydes were determined at temperatures
between 263 and 353 K at 50 Torr in helium or argon bath gases. The
temperature dependence of <I>k</I><sub>OH</sub> for both aldehydes was found to be
slightly negative. The tropospheric lifetime of hexanal and
<I>trans</I>-2-hexenal due to the chemical removal by OH radicals has been
estimated across the troposphere. The loss rate due to the OH chemical
removal was compared with the estimated photolysis rates. Our results show
that OH-reaction is the main loss process for these aldehydes in the
troposphere, although photolysis is not negligible for hexanal.
Albaladejo, J., Ballesteros, B., Jiménez, E., Martín, P., and Martínez, E.: A PLP-LIF kinetic study of the atmospheric reactivity of a series of C<sub>4</sub>-C$_7$ saturated and unsaturated aliphatic aldehydes with OH, Atmos. Environ., 36, 3231–3239, 2002.
Atkinson, R. and Arey, J.: Atmospheric degradation of volatile organic compounds, Chem. Rev., 103, 4605–4638, 2003.
Atkinson, R., Arey, J., Aschmann, S. M., Corchnoy, S. B., and Shu, Y.: Rate constants for the gas-phase reactions of \textitcis-3-hexen-1-ol, \textitcis-3-hexenylacetate, \textittrans-2-hexenal, and linalool with OH and NO<sub>3</sub> radicals and O<sub>3</sub> at 296$\pm $2 K, and OH radical formation yields from the O<sub>3</sub> reactions, Int. J. Chem. Kinet., 27, 941–955, 1995.
Cabañas, B., Martín, P., Salgado, S., Ballesteros, B., and Martínez, E.: An experimental study on the temperature dependence for the gas-phase reactions of NO<sub>3</sub> radical with a series of aliphatic aldehydes, J. Atmos. Chem., 40, 23–39, 2001.
D'Anna, B., Andresen, $\Phi$., Gefen, Z., and Nielsen, C. J.: Kinetic study of OH and NO<sub>3</sub> radical reactions with 14 aliphatic aldehydes, Phys. Chem. Chem. Phys., 3, 3057–3063, 2001.
Finlayson-Pitts, B. J. and Pitts Jr., J. N.: Chemistry of the Upper and Lower Atmosphere, Academic Press, San Diego, 2000.
Grosjean, D. and Williams, E. L.: Environmental persistence of organic compounds estimated from structure reactivity and linear free-energy relationships unsaturated aliphatics, Atmos. Environ., 26, 1395–1405, 1992.
Grosjean, D., Grosjean, E., and Gertler, A. W.: On-road emissions of carbonyls from light-duty and heavy-duty vehicles, Environ. Sci. Technol., 35, 45–53, 2001.
Grosjean, E., Grosjean, D., and Seinfeld, J. H.: Gas-phase reaction of ozone with \textittrans-2-hexenal, \textittrans-2-hexenyl acetate, ethylvinyl ketone, and 6-methyl-5-hepten-2-one, Int. J. Chem. Kinet., 28, 373–382, 1996.
Jiménez, E., Lanza, B., Garzón, A., Ballesteros, B., and Albaladejo, J.: Atmospheric degradation of 2-butanol, 2-methyl-2-butanol, and 2,3-dimethyl-2-butanol: OH kinetics and UV absorption cross sections, J. Phys. Chem. A, 109, 10 903–10 909, 2005a.
Jiménez, E., Ballesteros, B., Martínez, E., and Albaladejo, J.: Tropospheric reaction of OH with selected linear ketones: Kinetic studies between 228 and 405 K, Environ. Sci. Technol., 39, 814–820, 2005b.
Jiménez, E., Lanza, B., Ballesteros, B., and Albaladejo, J.: Atmospheric fate of hexanal and trans-2-hexenal: OH kinetic reaction and UV photolysis. 19th International Symopsium on Gas Kinetics. Orléans, France, 2006.
Keller-Rudek, H. and Moortgat, G. K.: MPI-Mainz-UV-VIS Spectral Atlas of Gaseous Molecules, http://www.atmosphere.mpg.de/enid/, 2006.
Kirstine, W., Galbally, I., Ye, Y. R., and Hooper, M.: Emissions of volatile organic compounds (primarily oxygenated species) from pasture, J. Geophys. Res. Atmos., 103, 10 605–10 619, 1998.
Krol, M., van Leeuwen, P. J., and Lelieveld, J.: Global OH trend inferred from methylchloroform measurements, J. Geophys. Res. Atmos., 103, 10 697–10 711, 1998.
Kwok, E. S. C. and Atkinson, R.: Estimation of hydroxyl radical reaction rate constants for gas-phase organic compounds using structure-reactivity relationship: an update, Atmos. Environ., 29, 1685–1695, 1995.
Logan, J. A.: Tropospheric ozone-seasonal behavior, trends, and anthropogenic influence, J. Geophys. Res. Atmos., 90, 10 463–10 482, 1985.
Madronich, S. and Flocke, S.: The role of solar radiation in atmospheric chemistry in Handbook of environmental chemistry, edited by: Boule, P., 1999.
Magneron, I., Thevenet, R., Mellouki, A., Le Bras, G., Moortgat, G. K., and Wirtz, K.: A study of the photolysis and OH-initiated oxidation of acrolein and \textittrans-crotonaldehyde, J. Phys. Chem. A, 106, 2526–2537, 2002.
Moortgat, G. K.: Important photochemical processes in the atmosphere, Pure Appl. Chem., 73, 487–490, 2001.
O'Connor, M. P., Wenger, J. C., Mellouki, A.; Wirtz, K., and Muñoz, A.: The atmospheric photolysis of $E$-2-hexenal, $Z$-3-hexenal and $E$,$E$-2,4-hexadienal, Phys. Chem. Chem. Phys., 8, 5236–5246, 2006.
Owen, S., Boissard, C., Street, R. A., Duckham, S. C., Csiky, O., and Hewitt, C. N.: Screening of 18 Mediterranean plant species for volatile organic compound emissions, Atmos. Environ., 31, 101–117, 1997.
Papagni, C., Arey, J., and Atkinson, R.: Rate constants for the gas-phase reactions of a series of C<sub>3</sub>-C$_6$ aldehydes with OH and NO<sub>3</sub> radicals, Int. J. Chem. Kinet., 32, 79–84, 2000.
Plagens, H.: Untersuchungen zum atmosphärenchemischen Abbau langkettiger Aldehyde, Thesis, University of Wuppertal (Germany), 2001.
Rodríguez, D., Rodríguez, A., Notario, A., Aranda, A., Diaz-de-Mera, Y., and Martinez, E.: Kinetic study of the gas-phase reaction of atomic chlorine with a series of aldehydes, Atmos. Chem. Phys., 5, 3433–3440, 2005.
Sander, S. P., Finlayson-Pitts, B. J., Friedl, R. R., Golden, D. M., Huie, R. E., Kolb, C. E., Kurylo, M. J., Molina, M. J., Moortgat, G. K., Orkin, V. L., and Ravishankara, A. R.: Chemical kinetics and photochemical data for use in atmospheric studies. Evaluation Number 14, JPL Pub. 02-05, Jet Propulsion Laboratory, Pasadena, 2002.
Smith, I. W. M. and Ravishankara, A. R.: Role of hydrogen-bonded intermediates in the bimolecular reactions of the hydroxyl radical, J. Phys. Chem. A, 106, 4798–4807, 2002.
Tadic, J., Juranic, I., and Moortgat G. K.: Photooxidation of $n$-hexanal in air, Molecules, 6, 287–299, 2001.
Tang, Y. X. and Zhu, L.: Wavelength-dependent photolysis of $n$-hexanal and n-heptanal in the 280–330-nm region, J. Phys. Chem. A, 108, 8307–8316, 2004.
Wildt, J., Kobel, K., Schuh-Thomas, G., and Heiden, A. C.: Emissions of oxygenated volatile organic compounds from plants part II: emissions of eaturated aldehydes, J. Atmos. Chem., 45, 173–196, 2003.