Extraction and clean-up methods for improvement of the chromatographic determination of polychlorinated biphenyls in sewage sludge-amended soils: Elimination of lipids and sulphur

Different extraction and clean-up methods for the determination of polychlorinated biphenyls (PCBs) in sewage sludge-amended soil were investigated. Soxhlet extraction with hexane-acetone (41:59) and simultaneous elimination of sulphur, with recently precipitated copper, and Florisil cartridge clean-up provided the best results. High-resolution GC with electron-capture detection achieved accurate identification and quantification of the PCBs. Initial pollutant concentrations in soil amended with sewage sludge ranged from 0.5 to 94 ng/g for PCB congeners. The weathering of the PCBs in sludged soil was monitored for a 168-day period. The results indicated that PCBs were persistent.