Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry coupled with laser desorption ionization (LDI) was used to probe chemical constituents of soot particles sampled from a co-flow diffusion flame fueled with a binary mixture of toluene and ethylene. The chemical formulas of thousands of mass spectrometric peaks were assigned according to the measured accurate molecular weights. Large polycyclic aromatic hydrocarbons (LPAHs) were found to be the major components in the complex mixtures. Compound class distribution analysis showed that the LPAH oxygen content grows with increasing height above the burner. iso-Abundance plots were employed to visualize the distributions of various molecules by sorting the molecular constituents into different types based on the carbon and double bond equivalence (DBE) numbers. Soot particles at Position 1 are nano-organic carbon particles, which are liquid-like and formed in the core of the flame at early stages of combustion. The mass spectra of soot particle in position 1 was selected for structural analysis of the constituent PAHs. Results show that PAHs in these soot particles successively grows by two carbon atoms.
|Original language||English (US)|
|Title of host publication||12th Asia-Pacific Conference on Combustion, ASPACC 2019|
|State||Published - Jan 1 2019|