Microscale analytical methods for the quantitative detection of PCBs and PAHs in small tissue masses

Microscale methods (MM) were evaluated and compared to traditional methods (TM) for measuring polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in spiked and standard reference fish and mussel tissues. MMs are advantageous because they use small tissue masses (ca. 100mg), and maintain sensitivity through reducing final extract volume (traditionally 1 ml) by an order of magnitude or more (40 microl-PCBs; 100 microl-PAHs). Procedural losses occurred in the MMs' combined cleanup/primary evaporation step (19% PAHs; 6% PCBs), and the final extract concentration (14% PAHs; 22% PCBs). The PAH MM performed comparably to the TM. Although most PCBs had recoveries >50%, the PCB MM generally yielded lower recoveries than the TM. Average method detection limits were 0.6 microg/kg (TM) and 1.0 microg/kg (MM) for PCBs and 25.7 microg/kg (TM) and 27.7 microg/kg (MM) for PAHs. MMs described for PCB and PAH tissue samples are potentially viable alternatives to TMs, and could lead to cost savings in bioaccumulation/toxicity tests.