Microwave-assisted extraction of OCPs, PCBs and PAHs concentrated by semi-permeable membrane devices (SPMDs)

Microwave-assisted extraction (MAE) has been evaluated as an alternative to dialysis for extraction of some water-borne hydrophobic contaminants sampled by semi-permeable membrane devices (SPMDs). Seven organochlorine pesticides (OCPs), 11 polychlorinated biphenyls (PCBs) and 13 polycyclic aromatic hydrocarbons (PAHs) were accumulated in SPMDs at nanogram levels and extracted with three 3-min irradiation cycles with 33 mL of a solvent mixture hexane-water (10:1,v/v) in each cycle. The developed MAE method gave for all analytes investigated statistically comparable extraction yields with those found by dialysis carried out with a total volume of 250 mL hexane for 48 h at room temperature. The recoveries of all the targeted contaminants were in the range of 65-105% with variation coefficients not exceeding 19%. The applicability of the MAE extraction was tested in field SPMDs samples deployed for 15 days in a sewage-treatment process. Our results show that MAE provides a remarkable reduction of time and solvent volume when used as an extraction method in the analysis of SPMDs.