Temporal Variation of BTEX at the Area of Petrol Station in Bangkok, Thailand

This work aims to find changing amount of BTEX in period of time and theirs concentration at difference positions surrounding the petrol station located at the boundary of Bangkok and Nonthaburi, Thailand. A carbon charcoal glass tube connected to a personal air pump was used to collect BTEX during 16 hrs (6 a.m. - 10 p.m.) divided into 4 periods. After sampling, BTEX was extracted from charcoal tubes and analyzed by GC/FID. The center of petrol station which is considered as the main point source has the highest BTEX average concentration: benzene 589.91±107.26 μg/m3, toluene 1,694.92±212.27 μg/m3, ethylbenzene 96.74±17.34 μg/m3, m,p-xylene 409.79±59.91 μg/m3, and o-xylene 123.96±16.01 μg/m3. Total BTEX at the center point are 12.8 and 22.9 times higher than those at roadside and the backside of petrol station, respectively. Temperature and humidity are possible meteorological variables which affect BTEX concentrations.