Ionic reaction mechanisms in pre-mixed flames disclosed by stable-isotope labelling

Abstract

The methane–oxygen fuel system was investigated using deuterium labelling methods. The pre-mixed flames were burnt on a simple quartz burner and sampled directly by a VG PlasmaQuad instrument, which consists of a quadrupole mass spectrometer equipped with a high-temperature molecular beam inlet. The genesis of the predominant ions C₃H₃⁺ and C₂H₃O⁺ and their eventual routes of decomposition are discussed. The proposed mechanisms are supported by thermochemical considerations and appropriate tandem mass spectrometric experiments on alternatively generated ions.