奎屯市大气VOCs浓度水平及物种的年变化

为了得到实时的大气挥发性有机物( VOCs)浓度组成和日变化特征，2013-2015年在新疆奎屯市区内高约25m的楼顶采用在线的气相色谱仪进行了为期3年的观测。结果表明，奎屯市TVOCs浓度年均值范围66.0-80.7ppbv，低碳烷烃、低碳稀烃、高碳烷烃、苯系物和高碳烯烃为主要的五类VOCs，其浓度之和占TVOCs浓度的84.1%。奎屯市冬季VOCS浓度值是年均值1.5倍、冬夏VOCS浓度相差3倍左右，与其他城市相比，大气挥发性污染物浓度水平整体是偏高。与前两年相比，2015年大气中卤代烃、苯系物、含氧（氮）VOCS的百分含量明显提升，分别上升15.6个百分点、6.5个百分点、5.9个百分点，大气VOCS有毒有害成分比例提升。由于在各类挥发性机物中，相同的条件下卤代烃与其它有机物相比，更容易发生光化学反应，因此，从卤代烃夏季含量很高的变化趋势看，奎屯市夏季发生光化学反应的能力不断增强。

The annual changes of concentration level and the kinds of VOCs in Kuitun

To find the real-time concentrations and temporal distribution of volatile organic compounds (VOCs) in Kuitun, Xinjiang, China, VOCs were observed by using online gas chromatograph on a roof of a building which was 25 meters high during 2013 to 2015. The results show that the range of annual average concentration of total VOCs (TVOCs) in Kuitun is from 64.8 to 82.8 ppbv, and the main classes of VOCs are light alkanes, light olefins, high alkanes, benzene series and high olefins, which accounted for 84.1% of TVOCs. The concentration of VOCs in winter was 4.5 times more than the annual average, and 5 times higher than that in summer. Compared with other cities, the concentration level of VOCs in Kuitun is higher as a whole. Compared with the last two years, the percentages of halohydrocarbon, benzene series and oxygen (nitrogen) VOCs in air was obviously increased by 15.6%, 6.5% and 5.9% respectively in 2015, so did the proportion of poisonous and harmful compositions of VOCs in air. Due to the easier photochemical reaction of halohydrocarbon than other organic matters under the same conditions, the ability of photochemical reaction has been increased constantly from the change trend point of view about the high content of halohydrocarbon in summer.