Characteristics of ambient volatile organic compounds and the influence of biomass burning at a rural site in Northern China during summer 2013

Volatile organic compounds (VOCs) were measured at a rural site in the North China Plain during summer 2013, which focused on VOCs characteristics and impact of biomass burning. Alkanes and halocarbons made the largest contribution to the sum of the mixing ratio of each VOC compound (total VOCs). Most VOC species mixing ratios had similar day-to-day variability, indicating that the air mass at the sampling site had small local perturbation. Accumulation of pollutants due to biomass burning and advection of plumes from urbanized areas upwind had important impact on diurnal variation patterns of the VOC group. Ethylbenzene/m,p-xylene ratio and its relationship with O3 indicated that sampling site received an aged air parcel. The aromatics and alkenes were the dominant contributors to total ozone formation potential (OFP). The top 5 VOC species based on OFP were toluene, isoprene, ethene, propene and n-Hexane. During the biomass burning period, VOCs had higher OFP values, especially the aromatics and alkynes. The backward trajectories indicated that extensive transport of biomass burning from the Shandong and Hebei provinces had an important effect on VOCs pollution levels.