Combined microwave-assisted extraction and gel permeation chromatography for the determination of chlorinated hydrocarbons in seal blubber and cod livers.

A fast and effective sample clean-up procedure for the quantitation of chlorinated hydrocarbons in seal blubber and cod livers is presented. Lipophilic sample ingredients are extracted by application of microwave energy. Microwave-assisted extraction (MAE) was performed with ethyl acetate and cyclohexane as solvent. Without exchange of the solvent, the organochlorine compounds are separated from matrix coextractives by gel permeation chromatography. Traces of matrix remainders were separated on deactivated silica prior to GC/ECD analysis. In this study we focused on quantification of PCB 153, PCB 138, PCB 180, HCB, and p,p'-DDE. In seal blubber, the recovery rates for these organochlorines were > 90% for the complete sample clean-up procedure. The standard deviation of the overall-method was within 5%. MAE of cod livers required softer conditions. After optimization of the MAE the organochlorine levels in cod liver were almost identical with those determined with another independent clean-up method.