Abstract:To establish the source profile of atmospheric volatile organic compounds (VOCs) in the airport area and clarify their pollution characteristics and source contributions, a continuous online monitoring of 116 VOC species was conducted from July 1, 2023 to June 30, 2024 at a site adjacent to the runway of Xi'an Xianyang International Airport. The monitoring adopted the cryogenic preconcentration sampling technique combined with gas chromatography-flame ionization detector/mass spectrometry (GC-FID/MS) for high-precision analysis. The key results are summarized as follows: (1) The average daily volume fraction of VOCs in the airport area was 33.66×10??, showing a distinct seasonal variation pattern of winter > autumn > spring > summer. Alkanes dominated the VOCs composition, followed by halogenated hydrocarbons, oxygenated volatile organic compounds (OVOCs), and alkenes. (2) Although the total volume fraction of VOCs in the airport area was slightly lower than that in the urban area, the ratio of the total volume fraction of alkanes, aromatics, and alkenes to OVOCs ranged from 2.93 to 5.55, which was significantly higher than the corresponding ratio (1.48) observed in the urban area during autumn. This characteristic confirms that VOCs in the airport area are mainly derived from primary emissions such as aircraft engine combustion and on-site vehicle exhaust, with the degree of atmospheric secondary conversion of VOCs being significantly weaker than that in the urban area. (3) Ozone Formation Potential (OFP) analysis revealed that alkenes, OVOCs, aromatics, and alkanes collectively contributed 96.22% to the total OFP. Among the VOC species, the top 10 contributors to OFP exhibited clear compositional features, including 3 OVOCs (acetaldehyde, trans-crotonaldehyde, propionaldehyde), 3 alkenes (ethylene, propylene, 1-butene), 3 aromatics (toluene, m/p-xylene, o-xylene), and 1 alkane (n-butane). Regarding seasonal differences in OFP contributions, the contribution of alkanes remained relatively stable across seasons; alkenes showed the lowest contribution in summer, OVOCs reached the highest contribution in spring, and aromatics exhibited a significantly lower contribution in spring. (4) Source apportionment using the Positive Matrix Factorization (PMF) model corrected by photochemical loss indicated that aircraft exhaust was the dominant source of atmospheric VOCs in the airport area, accounting for 29.6% of the total contribution. This was followed by liquefied petroleum gas/natural gas (LPG/NG) sources (23.9%) and emissions from ground support vehicles as well as surrounding motor vehicles (19.5%). Additionally, natural sources plus secondary formation sources (15.0%) and industrial emission sources (12.1%) also had certain contributions. This study provides scientific support for precise VOCs management and coordinated ozone pollution control in airport and transportation hub areas.