Ambient concentrations of biogenic volatile organic compounds in Southern Taiwan

Four observation stations in Southern Taiwan have been selected to measure ambient concentrations of biogenic volatile organic compounds (BVOCs). The biogenic VOCs measured include Isoprene, Monoterpene, Aldehydes, Ketones, Alkenes and Aromatics and the observation has been conducted from 1998 January to 1998 April.Samples are collected during the daytime and nighttime for consecutive 5 to 7 days in each station.The results indicate that aldehydes are the highest frequency of detection. More BVOCs are detected and their concentrations are higher for daytime than nighttime. The daytime average concentrations are between 6.5 μg/m3 to 246.4 μg/m3 while the nighttime average concentrations are between 1.7 μg/m3 to 151.1 μg/m3. Additionally, the VOC concentration increases at higher temperature and illuminance but has a tendency to decrease with increasing humidity.