Measurement of polychlorinated biphenyls in solid waste such as transformer insulation paper by supercritical fluid extraction and gas chromatography electron capture detection

In this work, a method for measuring polychlorinated biphenyls (PCBs) in contaminated solid waste was investigated. This waste includes paper that is used in electric transformers to insulate electric components. The PCBs in paper sample were extracted by supercritical fluid extraction and analyzed by gas chromatography-electron capture detection. The recoveries with this method (84–101%) were much higher than those with conventional water extraction (0.08–14%), and were comparable to those with conventional organic solvent extraction. Limit of detection was 0.0074 mg kg−1 and measurable up to 2.5 mg kg−1 for 0.5 g of paper sample. Data for real insulation paper by the proposed method agreed well with those by the conventional organic solvent extraction. Extraction from wood and concrete was also investigated and good performance was obtained as well as for paper samples. The supercritical fluid extraction is simpler, faster, and greener than conventional organic solvent extraction.

► Insulation paper in transformers could be contaminated with PCBs. ► PCBs are extracted from solid waste by supercritical fluid extraction (SFE). ► PCB recovery with conventional water extraction is much lower than that with SFE. ► The results obtained with SFE and conventional solvent extraction are similar. ► SFE is simpler, faster, and uses less solvent than conventional solvent extraction.