Solid Products of NO2 and O3 Uptake on Methane Flame Soot

Using a flow reactor with a movable insert and mass-spectrometric control of the gas composition, methane soot samples are treated with O3 and NO2 reagents until the surface is completely poisoned. A solution of the initial methane soot in acetonitrile and solid products of its reaction with oxidizing reagents O3 and NO2 is analyzed using high-resolution mass spectrometry with an electrospray ion source and gas chromatography (GC)–mass spectrometry (MS) with electron ionization. It is established that the original soot contains a number of aromatic compounds, including polycyclic compounds, which are completely consumed in the reaction with these oxidizing agents. Compounds from the paraffin class remain inert with respect to NO2 and O3. The products of the ozonization of prenitrated soot are the same as those of simple ozonation. The number of ozonation products is much higher than similar nitration products. This is the reason for the reactivity of nitrated soot with respect to the ozone uptake.