Maria Chiara Corviseria, Allan Polidorob, Marco De Polic, Claudia Stevanina, Tatiana Cheneta, Alberto Cavazzinic, Luisa Pastia, Flavio Antonio Franchinac

aDipartimento di Scienze dell’Ambiente e della Prevenzione, Università degli Studi di Ferrara, 44121 Ferrara, Italy
bDipartimento di Medicina Traslazionale e per la Romagna, Università degli Studi di Ferrara, 44121 Ferrara, Italy
cDipartimento di Scienze Chimiche, Farmaceutiche e Agrarie, Università degli Studi di Ferrara, 44121 Ferrara, Italy

Per- and polyfluoroalkyl substances (PFAS) are a family of manufactured compounds which have been widely used by consumers and industry since the 50s. Chemically, they are composed of a carbon chain bonded to fluorine atoms, with different functional groups at the end of the chain. Their persistence in the environment and potential impact on health make it crucial to establish reliable analytical methods for their detection. The purpose of this study is to assess the potential of thermal desorption tubes (a solvent-free, highly effective alternative to traditional methods) associated with gas chromatography and two-dimensional gas chromatography coupled with time-of-flight mass spectrometry to extract and identify (semi)volatile PFASs. The performance of thermal desorption tubes was evaluated by testing various sorbents (graphitized carbon black and phenylphenylenoxide polymers) along with different extraction parameters (conditioning temperature and extraction volume). The objective was to assess recovery and selectivity in terms of PFAS extraction. The extraction processes were optimized simulating environmental samples, using a certificate soil and DI water, spiked with a mixture of PFAS standards (MW range 264-571 Da), including fluorotelomer alcohols (FTOH), acrylates (FTAc), and alkyl sulfonamide (N-MeFOSA, N-EtFOSA, N-MeFOSE, and N-EtFOSE) derivatives. The most effective sorbent was poly(2,6-diphenylphenylene oxide) which is a type of porous polymer, although using graphitized carbon adsorbent was also helpful for the extraction of specific compounds. GC×GC was used to identify other major molecules in environmental samples and TOFMS to analyze the individual PFASs, even those belonging to the same subfamily, showing its effectiveness in differentiating between them. Conducting these primary tests was crucial in comprehending the behavior of PFAS compounds concerning their families both as standards and in actual samples. The thermal desorption tubes proved to be effective for extracting these compounds while minimizing the use of solvents. When combined with (GC×)GC-TOFMS, the method provides an alternative to traditional extraction methods.