Development and application of a simplified sampling method for volatile polyfluorinated alkyl substances in indoor and environmental air

A new, fast and simple sampling method using commercially available Isolute ENV+ solid-phase extraction (SPE) cartridges for the enrichment of neutral, volatile polyfluorinated alkyl substances (PFAS) was developed and applied to selected air samples. The SPE cartridges showed good retention capacity for the target analytes, and most of the investigated compounds could be quantified in 20 m3 indoor air. Employing the developed method, it was shown that high levels of selected fluorotelomer alcohols (FTOHs) and N-alkyl fluorooctane sulfonamides/-ethanols (FOSAs/FOSEs) evaporated from a paraglider. Furthermore, the new method was compared to the ‘classical’ approach using glass-fibre filters (GFFs) and XAD-2 resin sandwiched between polyurethane foam plugs (PUF/XAD/PUF) to investigate environmental air concentrations in metropolitan Hamburg. Due to the high counter pressure of SPE cartridges, only low-volume air sampling was feasible. Therefore, the trace levels of FOSAs/FOSEs occurring in environmental air could only be quantified occasionally in the samples enriched on SPE cartridges. However, quantitative analysis of the higher concentrated 6:2 FTOH, 8:2 FTOH and 10:2 FTOH was possible in all low-volume environmental air samples. Finally, the determination of ionic PFAS, including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), bound to airborne particles in the air samples from Hamburg is described.