Application of thermal desorption to the biological monitoring of organic compounds in exhaled breath.

We have developed a thermal desorption-gas chromatographic method for the analysis of organic compounds in exhaled breath air, to be used in the biological monitoring of environmental exposure. The exhaled breath sampler is based on the concentration of compounds present in alveolar air in a solid sorbent material. Isoflurane (1-chloro-2,2,2-trifluoroethyl-difluoromethyl-ether), an inhaled anaesthetic used widely in surgery, and styrene, used in boat construction and the manufacture of fibreglass-reinforced plastics, are partially eliminated from the body in exhaled breath, samples of which can therefore be used to monitor biological exposure to these two organic compounds. Recoveries were tested in controlled atmospheres of isoflurane or styrene, with Chromosorb 106 or Tenax, respectively, as the adsorbent. We also investigated the influence of relative humidity, an important factor in breath sampling, on adsorption.