Simple analysis of volatile organic compounds (VOCs) in the atmosphere using passive samplers

A simple analysis of volatile organic compounds (VOCs), such as benzene, toluene, m,p-xylene, and o-xylene, at low levels in the atmosphere was conducted using passive samplers. The methods were applied to analyzing the behavior and origin of VOCs in Kyoto City. The passive samplers were exposed for 7 - 14 days at sampling sites in Kyoto City and for 30 days in the mountains (Mt. Hiei and Mt. Daimonji). Shibata gas-tube samplers packed with activated carbon were used for the determination of VOCs. The absorbed VOCs were extracted into carbon disulfide (CS2) and measured by FID-GC. The determination limits and relative standard deviations for VOCs were 0.3 microg/m3 and 3%, respectively. The samplers were set up at 5 sites in March, 2001 and at 13 stations on Mt. Hiei in November, 2002. The average concentrations of ambient benzene, which were higher than the environmental criterion (3.0 microg/m3), except for those on Mt. Daimonji from March, 2001, to February, 2002, decreased to below 3.0 microg/m3 from March, 2002, to February, 2003. The decrease in ambient benzene may have been due to a decrease in the benzene content in gasoline by the end of 1999, and also by implementation of the Pollutant Release and Transfer Register (PRTR) Act in 2001.