沿海地区不同来向气团中非甲烷挥发性有机物的组成特征研究

在我国东部沿海城市两个采样点上对不同来向气团中非甲烷挥发性有机物(NMVOCs)的组成特征进行了观测研究.采用离线方法(苏玛罐采样、三级冷阱预浓缩、GC-FID分析)进行样品测定;利用拉格朗日混合单粒子轨道模型(HYSPLIT-4)模拟计算气团后向轨迹.结果表明,观测期间总非甲烷挥发性有机物(TNMVOCs)浓度的变化范围为4.31×10~(-9)～68.97×10~(-9)(体积分数,下同),主要受工业活动、溶剂和液化石油气使用影响;不同来向气团的NMVOCs组成特征有明显差异,陆地气团的NMVOCs浓度高于海洋气团,途经工业较发达地区的气团其烯烃、芳香烃和烷烃占比较高,受机动车排放的影响较大.

Characteristics of non-methane volatile organic compounds in coastal area from different air masses

The composition characteristics of non-methane volatile organic compounds (NMVOCs)in different air masses at two sites in the eastern coastal cities were observed. The off-line method (SUMMA can sampling, three-stage pre-concentration, GC-FID analysis) was used, and hybrid single particle lagrangian integrated trajectory (HYSPLIT-4) was performed to simulate the backward trajectory. Results showed that concentration of total non-methane volatile organic compounds (TNMVOCs) ranged from 4.31×10^-9 to 68.97×10^-9 during the observation period, which was mainly affected by industrial activities, solvent and LPG use. The composition characteristics of NMVOCs under different air masses were significantly different. The concentration of NMVOCs form land air masses was higher than that from marine air masses. The air masses from industrially developed areas accounted for a relatively high proportion of alkenes, aromatic hydrocarbons and alkanes, which were greatly affected by vehicle emissions.