Objective: A method for monitoring low concentration of benzene, toluene, p-xylene, o-xylene (BTX) in ambient air is set up. The optimum of desorption and analysis parameter is selected.
Methods: Tenax TA adsorption/thermal desorption/capillary gas chromatography is used.
Results: The relative standard deviation of benzene, toluene, p-xylene, o-xylene in ambient air are from 4.30% to 10.81%, which shows this method has good repeatability. The recoveries of BTX are more than 94%. The minimum detectable concentration to benzene, toluene, p-xylene, o-xylene is 0.09, 0.12, 0.23, 0.26 microg/m3 respectively.
Conclusion: This method can be used to determinate low concentration of BTX in ambient air.