Characterization and source identification of ambient VOCs in Jinan, China

For 2 years, the concentrations and variance of 56 VOCs were continuously monitored with an on-line gas chromatography and the data were analyzed to characterize the local volatile organic compounds (VOCs) in the atmosphere and identify the major sources of the pollutants. The abundant VOCs were found to consist of C3 similar to C5 alkanes, propylene, cis-2-butene, toluene, and m/p-xylene. The results showed that the seasonal average concentrations of VOCs followed in decreasing order: summer > winter > autumn > spring. In summer, the alkane pollution was the most severe. The diurnal variation of alkanes, alkenes, and VOCs showed a bimodal distribution with two peaks, one in the morning and one in the evening. This profile was consistent with local traffic rush hours, and the average hourly toluene/benzene ratio was less than two. Based on the principal component analysis (PCA), it was found that the major sources of VOCs were consistent with automobile exhaust, industry, and biomass combustion in this study.