Identification and Quantification of Aromatic Hydrocarbons Adsorbed on Soot from Premixed Flames of Kerosene, Synthetic Kerosene, and Kerosene-Synthetic Biofuels

In the current study, the chemical characterization of polycyclic aromatic hydrocarbons (PAHs) adsorbed on soot from premixed flames of synthetic paraffinic kerosene (SPK), conventional kerosene (Jet A-1), and Jet A-1/synthetic biofuel blends was carried out. Jet A-1 and SPK liquid fuels were analyzed with NMR to provide supporting information on their chemical composition. The analytical procedure used to characterize PAHs fraction in soot samples includes the following: (i) filtration of the soot samples diluted into n-hexane through PTFE filters, (ii) automated solid-phase extraction (A-SPE) for fractioning and cleaning-up the soot extracts, and (iii) chromatographic analysis of every fraction by reverse high-performance liquid chromatography (RPLC) with photodiode array (PDA) detection. Application of the aforementioned methodology allowed the identification of 78 compounds including indene, toluene, and 76 PAHs. Moreover, the relative abundance of five-membered-ring PAHs and alkyl PAHs was evaluated, and 19 PAHs (16 EPA PAHs, 1-methylnaphthalene, 2-methylnaphthalene, and coronene) were quantified. The PAR characterization should contribute to improve our understanding of atmospheric reactivity of soot and other environmental aspects of aromatic compounds adsorbed on soot.