THE PRELIMINARY STUDY ON MEASURED RESULTS OF AMBIENT VHCs IN BEIJING AREAS

The variation of atmospheric concentration of C2～C10 volatile hydrocarbon compounds (VHCs)is measured out in Beijing areas using Tenax TA and Carbosieve sorption-thermodesso rption-capillary gas chromatography.113 samples are collected during the period of September 2001 to August 2003.55 VHCs species are detected including 26 alkanes, 19 alkenes and 10 aromatics.The average mass concentration of VHCs is 364.3 ±99.3 μg/m³. The seasonal peak value is 546.9 ±353.5 μg/m³w hich appears in autumn.The valley value appears in summer which is 251.8 ±152.4 μg/m³.The VHCs average concentration is 30% in the heating season more than that in the non-heating season.The average concentration in the urban area is 10% higher than that in the suburbs.There are the significant daily variations of VHCs in Beijing.Results show that the polluted levels of ambient air depended mainly on the vehicle emissions and the meteorological conditions.