AbstractThe kinetics of the destruction of diisopropyl methylphosphonate (DIMP) in corona discharge has been studied using a flow tubular coaxial wire dielectric barrier corona discharge reactor. The identification and quantitative determination of DIMP, its destruction intermediates, and phosphorus‐containing destruction products were performed using molecular beam mass spectrometry and gas chromatography/mass spectrometry. Active discharge power was varied in the range 0.01–5 W. The destruction products such as isopropyl methylphosphonate, methylphosphonic acid, and orthophosphoric acid were found on the reactor walls. The dependence of the extent of the destruction, D (D = 1 − X / X0, where X and X0 are DIMP mole fractions at the outlet and the inlet of the reactor), on the specific energy deposition Ex (Ex = PF−1 X0−1, where F is the carrier gas flow and P is the power dissipated in discharge reactor) was measured over the DIMP mole fraction range 60–500 ppm at the pressure of 1 bar and the temperature of 340 K. Over the range of the experimental conditions studied the destruction obeys the “pseudo‐first‐order” kinetic law: ln(1 − D) = −KEx. Plausible mechanisms of the destruction are discussed. It was concluded that ion mechanism is the major one responsible for the destruction process. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 331–337, 2002