A new method of measuring gaseous semi-volatile organic compounds (PAHS) by solid phase micro extraction (SPME)

A methodology based on the SPME technique was developed for the quantitativ e measurement in air of semi- volatile organic compounds (PAHs). The invest igated PAHs were the seven ones which can be found in air gaseous form, acc ording to their vapour pressures i.e. naphthalene (Nph), fluoranthene (Ft), acenaphthene (Ace), fluorene (FI), phenanthrene (Phe), pyrene (P), and ace naphthylene (Act). A standard gaseous generation based on sublimation equil ibrium was developed in order to calibrate the PDMS (polymethyldi siloxane) 7 mum fibre. The relation between the equilibrium constant K and temperatu re T was determined for each studied compound. Thus, two different behaviou rs were observed: one for naphthalene, which shows a linear relationship, a nd another for the other PAHs, which show a broker linear relationships. Ne vertheless, the determined constants can be used to compute the concentrati on of any gas phase at any temperature.