Use of carbon adsorption traps combined with high resolution gas chromatography – mass spectrometry for the analysis of polar and non‐polar C4‐C14 hydrocarbons involved in photochemical smog formation

A method has been developed for the collection and analysis of polar and non-polar C4-C14 hydrocarbons involved in the formation of photochemical smog. Enrichment of hydrocarbons from both polluted and unpolluted areas has been achieved with three-stage traps packed with carbon adsorbents of different surface area; the use of a home-made desorption unit employing cryofocusing then enables the determination of the compounds by HRGC-FID. Two-stage traps filled with graphitic carbon have been used prior to GC-MS identification and quantitation of compounds producing overlapping peaks. The methodology has been tested in the urban area of Rome and in a pine forest, and more than 140 different compounds identified and quantitated. Many of the constituents were found to be oxygenated, either formed by photochemical reactions or of anthropogenic origin.