Analysis of perfluorooctanoate (PFOA) and other perfluorinated compounds (PFCs) in the River Po watershed in N-Italy

C 7–C 11 perfluorinated carboxylates (PFACs) and perfluorooctansulfonate (PFOS) were analysed in selected stretches of the River Po and its major tributaries. Analyses were performed by solid-phase extraction (SPE) with Oasis ® HLB cartridges and methanol elution followed by LC–MS–MS detection using 13C-labelled internal standards. High concentration levels (∼1.3 μg l −1) of perfluorooctanoate (PFOA) were detected in the Tánaro River close to the city Alessandria. After this tributary, levels between 60 and 337 ng l −1 were measured in the Po River on several occasions. The PFOA concentration close to the river mouth in Ferrara was between 60 and 174 ng l −1. Using the river discharge flow data in m 3 s −1 at this point (average ∼920 m 3 s −1 for the year 2006), a mass load of ∼0.3 kg PFOA per hour or ∼2.6 tons per year discharged in the Adriatic Sea has been calculated. PFOS concentration levels in the Po River at Ferrara were ∼10 ng l −1.