Atmospheric degradation of pyridine: UV absorption spectrum and reaction with OH radicals and O3

M. Errami (1, 2) , Gisèle El Dib (3) , M. Cazaunau (4) , E. Roth (2) , R. Salghi (1) , Abdelwahid Mellouki (4) , A. Chakir (2)

1 ENSA - Ecole Nationale des Sciences Appliquées [Agadir]
2 GSMA - Groupe de spectrométrie moléculaire et atmosphérique
3 IPR - Institut de Physique de Rennes
4 ICARE - Institut de Combustion, Aérothermique, Réactivité et Environnement

The UV absorption spectrum of pyridine and its gas phase reactions with OH radicals and O3 were investigated. UV absorption cross-sections were determined by using a D2-lamp system in the range 200–350 nm. The kinetic studies were carried out at room temperature and atmospheric pressure of purified air. The rate coefficient for the reaction of pyridine with OH was determined relative to that with acetone while that with O3 was measured under pseudo first order conditions. The rate coefficients obtained are (in cm3 molecule− 1 s− 1): k(OH + pyridine) = (5.40 ± 0.80) × 10−13 and k(O3 + pyridine) = (3.28 ± 1.70) × 10−20. © 2016 Elsevier B.V.

Keywords: Acetone; Air purification; Atmospheric pressure; Chemical reactions; Electromagnetic wave absorption; Enzyme kinetics; Free radicals; Light absorption; Ozone; Phase interfaces; Pyridine; Atmospheric simulations; OH radical; Rate coefficients; Tropospheric lifetime; UV absorption; Absorption spectroscopy

Domains: Physics [physics]; Chemical Sciences

M. Errami, Gisèle El Dib, M. Cazaunau, E. Roth, R. Salghi, et al.. Atmospheric degradation of pyridine: UV absorption spectrum and reaction with OH radicals and O3. Chemical Physics Letters, 2016, 662, pp.141--145. ⟨10.1016/j.cplett.2016.09.030⟩. ⟨hal-01380706⟩