Polycyclic aromatic hydrocarbons and their oxygenated derivatives in urban aerosol: levels, chemical profiles, and contribution to PM2.5 oxidative potential

• DOI: 10.1007/s11356-021-16858-z
• Publication Date: 2022-03-17T04:38:27Z
• Authors: Maria Chiara Piet...; Dimitri Bacco; Giorgia Demaria; Mara Russo; Fabiana Scotto; Arianna Trentini
• Keywords: Dithiothreitol; Seasonality

Abstract The concentrations of polycyclic aromatic hydrocarbons (PAHs) and quinones, a subgroup oxygenated PAHs (oxy-PAHs), were measured in PM 2.5 samples collected during warm (May–June 2019) cold (February–March 2020) seasons the city Bologna, Italy. Total concentration was nearly double winter (6.58 ± 1.03 ng m −3 ) compared with spring (3.16 0.53 ), following trend mass concentration. Molecular diagnostic ratios suggested that, together traffic, biomass burning dominant emission source contributing to peaks registered season. Quinone level constant both seasons, being 1.44 0.24 , that may be related increased secondary formation season, as confirmed by higher Σoxy-PAHs/ΣPAHs ratio than winter. oxidative potential (OP) assessed using acellular dithiothreitol (DTT) ascorbic acid (AA) assays. obtained responses showed strong seasonality, volume-normalized (OP V values spring, i.e., OP DTT : 0.32 0.15 nmol min −1 vs. 0.08 0.03 AA 0.72 0.36 0.28 0.21 . Both significantly associated total PAHs, general descriptor redox-active PAH derivatives, co-emission from sources or atmospheric oxidation parent PAHs. Otherwise, only significant correlation Ʃoxy-PAHs