The composition and concentration of hydrocarbons in the range of C2 to C18 emitted from motor vehicles

Abstract Sampling was carried out in the Caldecott Tunnel, located in the San Francisco (California) area. Three daily samples were collected, using stainless steel canisters and Tenax-TA solid adsorbent cartridges, over 2 days in June 1991. The samples were analyzed using high resolution gas chromatographic separation and Fourier transform infrared/mass spectrometric detection (GC/IRD/MSD) or flame ionization detection (FID) of individual hydrocarbons. The comparison of hydrocarbon concentrations found in the Tenax and canister samples and the assessment of the contribution of semivolatile hydrocarbons (C10–C18 range) to total non-methane hydrocarbons (C2–C10), as measured by the canister method, is presented.