Clossed-vessel assisted microwave extraction of polychlorinated biphenyls in marine mussels

A reliable and simple procedure to extract polychlorinated biphenyls (PCBs) from marine mussels using microwave energy is proposed. Freeze-dried mussels were subjected to MASE (Microwave Assisted Solvent Extraction) in a closed-vessel microwave system with n-pentane-sodium hydroxide (5 %) or dichloromethane-pentane (1:1) at different temperatures (70 and 90 oC), the extraction time was 10 minutes. Sample extract cleanup procedure was performed by using alumina. Gas chromatog- raphy-mass spectrometry and gas chromatography-electron capture detector were employed for individual congener identification and determination. The influence of the following variables on microwave extraction of PCBs has been studied: extraction tem- perature, solvent volume, solvent nature, cleanup procedure time and volume of sodium hydroxide solution. Recoveries for PCBs were between 77 and 106 % with relative standard deviation between 2 to 20 %. Validation of the extraction process was carried out by processing a certified reference material. Microwave Assisted Solvent Extraction was compared to Soxhlet extraction.