Microwave‐Assisted Extraction (MAE) of Polychlorinated Biphenyls and Polychlorinated Dibenzo‐p‐Dioxins from Fly Ash and Sea Sediments: Effect of Water and Removal of Interferences

Abstract

This study involved microwave‐assisted extraction (MAE) of polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxins (PCDDs) from fly ash and sea sediments. The effect of the addition of water to the extracting solvent (solvation) and sample matrices (wetting) on the variation of recoveries was studied under four concentrations of a toluene–isopropyl alcohol (IPA) mixture. The results indicate that MAE, using 1–2% of solvation or 10–20% of wetting in 90:10 (v/v) of toluene–IPA mixture, was the most effective treatment in isolating PCBs and PCDDs from the samples. Multi‐layer column chromatography on neutral and acidic silica gel with n‐hexane was used for cleaning up the extracts. In addition, alumina column clean‐up was performed to remove chromatographic interferences from sediment extracts. High performance liquid chromatography (HPLC) with ultraviolet (UV) detection was employed to identify and quantify the analytes.

Acknowledgment

This study was supported by grant No. (R01‐1999‐000‐00049‐0) from the interdisciplinary research program of the KOSEF.