Comparison of various extraction and clean-up methods for the determination of polycyclic aromatic hydrocarbons in sewage sludge-amended soils

Different extraction and clean-up methods for the determination of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge-amended soil were investigated. Soxhlet plus saponification extraction and silica gel clean-up provided the best results. HPLC with a programmable fluorescence detector performed accurate identification and quantification of PAHs. The initial PAH concentrations in sewage sludge-amended soil ranged from 8 ng/g for benzo[a]fluoranthene to 93 ng/g for phenanthrene, with a total PAH concentration of 417 ng/g. The weathering of PAHs in sludged soil was monitored for a 141-day period. The results indicated that low-molecular-mass PAHs were susceptible to abiotic and biotic loss processes.