Polycyclic aromatic hydrocarbons in wooden railway beams impregnated with coal tar: Extraction and quantification by GC-MS

An analytical technique for the simultaneous determination of PAHs (polycyc lic aromatic hydrocarbons) in wooden railway beams, impregnated with coal t ar for their protection, has been developed, based on the effective extract ion of the PAHs and their determination by GC-MS. Two extraction techniques , the Soxhlet and the ultrasonic one, using two different solvents, hexane and toluene have been compared for their efficiency for PAHs which can be d etermined in ppb-ppt range after optimised clean up and enrichment. Several parameters, such as the degree of impregnation of the wooden beams, the ef fect of sun radiation on the degradation of the PAHs and their migration to the soil have been investigated by following the concentration of the PAHs and that of their methylated products found at various sampling positions. The results are useful for the decision about recycling procedure or their further disposal.