STUDY OF THE DEGRADATION BY OZONE OF ADSORBENTS AND OF HYDROCARBONS ADSORBED DURING THE PASSIVE SAMPLING OF AIR

The effect of ozone on four adsorbents (Tenax-TA, Tenax GR, Carbotrap, and Chromosorb 106) during the passive sampling of air has been investigated by exposure to ozone at 180 ppb for 1 week. Generally no artifact compounds were found to form on Carbotrap or Chromosorb 106. Several new peaks appeared in the chromatograms of Tenax-TA and Tenax-GR, the most significant being benzaldehyde and acetophenone. The effect of ozone on selected hydrocarbons (isoprene, benzene, toluene, p-xylene, o-xylene, alpha-pinene, and beta-pinene), adsorbed on Tenax-GR during passive sampling, was also investigated by exposure to ozone at different concentrations (60, 120, and 180 ppb) for 1 week. Minor destruction by ozone was only observed for beta-pinene (4 %) at an ozone concentration of 180 ppb.