[Characteristics and Source Apportionment of Ambient Volatile Organic Compounds in Winter in Jincheng]

Air samples were collected and analyzed by GC-MS to investigate the component characteristics of volatile organic compounds (VOCs) in winter in Jincheng. PMF, ratio analysis, and the backward trajectory model were used to investigate sources of VOCs. Ozone formation potential and secondary organic aerosol formation potential were calculated, in order to analyze the environmental implications of detected VOCs. Results showed that the average concentration of VOCs was 93.35 μg·m^-3 in Jincheng, with the most abundant component being alkane (52.91 μg·m^-3 and 56.68% of total VOCs). Based on PMF analysis, five sources of ambient VOCs in Jincheng were identified, namely industrial emission sources (33.71%), fuel combustion sources (30.27%), vehicle emissions (26.28%), solvent evaporation sources (9.00%), and plant emission sources (0.74%). Ratios of B/T and i-pentane/n-pentane were 1.58±0.68 and 2.07±0.43, indicating that VOCs were derived from the mixture of road and coal combustion sources. Clustered analysis of the air mass backward trajectory showed that three air masses cluster, which were accounting for 50%, 25% and 25% of the total back trajectories respectively, all came from the northwest, and industrial pollution from the northwest might therefore significantly influence VOCs in Jincheng. With low wind speed (<3 m·s^-1), the air quality index, concentration of total VOCs, and contribution rate of vehicle emissions were 143, 162.48 μg·m^-3, and 46.16%, respectively, higher than values at faster wind speeds (3-6.9 m·s^-1). Ozone formation potential and secondary organic aerosol formation potential of aromatic hydrocarbons, which had the highest formation potential, were 98.89 μg·m^-3 and 1.21 μg·m^-3, respectively, accounting for 37.28% and 97.01% of total formation potential. To reduce the pollution of VOCs in Jincheng, it is important to control industrial emissions, vehicle emissions, and fuel combustion emissions.