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, A lkenes and Aromatics and the observation has been conducted from 1998 Janua ry to 1998 April. Samples are collected during the daytime and nighttime fo r consecutive 5 to 7 days in each station. The results indicate that aldehy des are the highest frequency of detection. More BVOCs are detected and the ir concentrations are higher for daytime than nighttime. The daytime averag e concentrations are between 6.5 mu g/m(3) to 246.4 mu g/m(3) while the nig httime average concentrations are between 1.7 mu g/m(3) to 151.1 mu g/m(3). Additionally, the VOC concentration increases at higher temperature and il luminance but has a tendency to decrease with increasing humidity. (C) 1999 Elsevier Science Ltd. All rights reserved.