Characteristics, chemical transformation and source apportionment of volatile organic compounds (VOCs) during wintertime at a suburban site in a provincial capital city, east China

Based on the continuous online measurements of volatile organic compounds (VOCs) at a suburban site in Jinan, Shandong province in the wintertime of 2021, characteristics, chemical transformations and sources of VOCs were analyzed. The total mixing ratio of VOCs was 30.35 ± 19.9 ppbv, with alkanes being the most abundant species. Alkenes and aromatics were the major contributors to the hydroxyl radical loss rate (LOH) and the ozone formation potential (OFP), accounting for 44.9% and 32.7% to LOH, and 43.2% and 33.4% to OFP, respectively. Aromatics had the primary contribution (98.1%) to the secondary organic aerosol potential (SOAP), and the high correlation between SOAP and PM2.5 concentrations (R = 0.70) suggested that VOCs were critical precursors of PM2.5. Coal/biomass burning and motor vehicle emissions were the main sources of VOCs (24.6% and 23.8%, respectively), followed by petrochemical and fuel evaporation (19.9%), industrial sources (16.9%), and liquefied petroleum gas/natural gas use (14.8%). Backward trajectories and the potential source contribution function (PSCF) analysis results suggested that short-range transport from the southeast was the primary potential source of VOC concentrations in suburban Jinan. The results can provide theoretical support for local governments to develop VOC emission control strategies in suburban areas.