Fast, Repetitive GC/MS Analysis of Thermally Desorbed Polycyclic Aromatic Hydrocarbons (PAHs) from Contaminated Soils

A syslem for on-line analysis of organic vapors by short column gas chromatography/mass spectrometry (GC/MS) has been used to monitor products from a thermal soil desorption reactor. The system consists of a unique air sampling inlet with a 1 meter long capillary column coupled directly to a modified Ion Trap Mass Spectrometer (Finnigan MAT) with demonstrated detection limits for alkylbcn-zencs in the low ppb range. In this work the mobile instrument is used for repetitive GC/MS and GC/MS n (tandem MS) analysis at 30 to 60s intervals of PAH products from coal tar contaminated soils in a bed characterization reactor. Results for naphthalene through dibenzanthracenes arc compared to conventional. more detailed GC/MS analyses of extracts from soil before and after thermal treatment.