Kinetic Study of the OH-isoprene and O3-isoprene reaction in the atmosphere simulation chamber, SAPHIR

Kinetic studies conducted in the new atmosphere simulation chamber SAPHIR at the Research Center Julich allow a thorough investigation of oxidation of isoprene induced by O-3 and the OH radical under atmospheric conditions. Rate coefficients for the O-3-isoprene and OH-isoprene reaction are determined from measured concentration-time profiles. For the reaction of O-3 with isoprene the rate coefficient is determined to be (9.6 +/- 0.7) x 10(-18) cm(3) molecule(-1) s(-1) at 286 K. The rate coefficient for the reaction OH + isoprene is (10.0 +/- 1.2) x 10(-11) cm(3) molecule(-1) s(-1) at 294 K. The kinetic parameters determined in SAPHIR at atmospheric concentrations agree well with recent recommendations.