[Chemical Characteristics and Sources of Volatile Organic Compounds in Shanghai During an Ozone and Particulate Pollution Episode in May 2019].

In the urban area of Shanghai during the complex pollution episode, ozone and PM2.5 were continuously measured from May 1 to May 28, 2019. The characterization of volatile organic compounds (VOCs) and their relationship with secondary formation were studied. The results show that in May 2019, there were four different ozone and PM2.5 pollution processes in Shanghai. The combined pollution of PM2.5 and ozone that occurred under the meteorological conditions of average temperature of approximately 26℃ and relative humidity of approximately 40% was analyzed. The photochemical consumption of VOCs was significantly positively correlated with the maximum net growth of O3 and there was a significant positive correlation between SOAP and PM2.5. The key reactive species of VOCs that significantly contribute to ozone generation were m,p-xylene, ethylene, toluene, propylene, and o-xylene. The key reactive species that significantly contribute to secondary organic aerosols (SOA) were toluene, m,p-xylene, ethylbenzene, o-xylene, and 1,2,3-trimethylbenzene.