[Characteristics and Sources of Volatile Organic Compounds （VOCs） in Luohe City During Summer]

Luohe City is an important node city in the Central Plains Urban Agglomeration in China, where the atmospheric ozone （O₃） pollution situation has been serious in recent years. In order to provide a scientific basis for O₃ pollution control, the online filed observation of O₃ precursor volatile organic compounds （VOCs） was carried out in Luohe City in July 2022 to understand their variation characteristics and sources. The mean ratio of φ（TVOCs） during the observation period was （16.49±5.73）×10^-9. Among them, alkane （33.7%）, oxygenated volatile organic compounds OVOC （24.0%）, and halohydrocarbon （21.9%） accounted for the top three. The results from source apportionment showed that the main VOCs sources （contributions） included the natural gas （NG） use （20.1%）, regional transport （14.8%）, solvent use （14.2%）, gasoline vehicle emissions （12.3%）, industrial emissions （11.6%）, diesel vehicle emissions （10.5%）, liquefied petroleum gas （LPG） use （9.8%）, and plant emissions （6.7%）. OVOC contributed the most to ozone formation potential （OFP） and free radical loss rate （L_·OH）. The results showed that the contribution of motor vehicle exhaust （>22.8%） was the primary source of VOCs in Luohe City. However, other sources were complex and with comparable contributions, requiring the development of targeted and comprehensive prevention and control measures.