Optimised chromatographic method for the measurement of selected polychlorinated biphenyls in ambient air

The focus of this study was to optimise selected polychlorinated biphenyl analysis in air by gas chromatography. Sample preparation was improved by using an automatic solid/liquid extraction system and columns with 1.5 g of Florisil for cleaning extracts. Better precision on clean-up results was obtained from Florisil cartridges, when compared to those obtained with silica gel. Analytical procedure was checked by participating in an inter-comparison exercise. Finally, we have considered usefulness of evaluating uncertainties associated to our method because of the large handling samples and the extremely low concentrations of PCBs in ambient air.