A multi-platform approach for the comprehensive analysis of per- and polyfluoroalkyl substances (PFAS) and fluorine mass balance in commercial ski wax products

• Published in: Analytica chimica acta 2024-07, Vol.1314, p.342754, Article 342754
• Main Authors: Gonzalez de Vega, Raquel, Plassmann, Merle, Clases, David, Zangger, Klaus, Müller, Viktoria, Rosenberg, Erwin, Reimann, Anders, Skedung, Lisa, Benskin, Jonathan P., Feldmann, Jörg
• Format: Article
• Language: English
• Subjects: 19F NMR; Caprylates - analysis; Caprylates - chemistry; CIC; Fluorine - analysis; Fluorine - chemistry; Fluorine mass balance; Fluorocarbons - analysis; Fluorocarbons - chemistry; ICP-MS; Pyrolysis-GC-MS; Target PFAS; Waxes - analysis; Waxes - chemistry
• ISSN: 0003-2670; 1873-4324; 1873-4324
• DOI: 10.1016/j.aca.2024.342754

The unique properties of per- and polyfluoroalkyl substances (PFAS) have led to their extensive use in consumer products, including ski wax. Based on the risks associated with PFAS, and to align with PFAS regulations, the international ski federation (FIS) implemented a ban on products containing “C8 fluorocarbons/perfluorooctanoate (PFOA)” at all FIS events from the 2021/2022 season, leading manufactures to shift their formulations towards short-chain PFAS chemistries. To date, most studies characterising PFAS in ski waxes have measured a suite of individual substances using targeted analytical approaches. However, the fraction of total fluorine (TF) in the wax accounted for by these substances remains unclear. In this study, we sought to address this question by applying a multi-platform, fluorine mass balance approach to a total of 10 commercially available ski wax products. Analysis of TF by combustion ion chromatography (CIC) revealed concentrations of 1040–51700 μg F g−1 for the different fluorinated waxes. In comparison, extractable organic fluorine (EOF) determined in methanol extracts by CIC (and later confirmed by inductively-coupled plasma-mass spectrometry and 19F- nuclear magnetic resonance spectroscopy) ranged from 92 to 3160 μg g−1, accounting for only 3–8.8 % of total fluorine (TF). Further characterisation of extracts by cyclic ion mobility-mass spectrometry (IMS) revealed 15 individual PFAS with perfluoroalkyl carboxylic acid concentrations up to 33 μg F g−1, and 3 products exceeding the regulatory limit for PFOA (0.025 μg g−1) by a factor of up to 100. The sum of all PFAS accounted for only 0.01–1.0 % of EOF, implying a high percentage of unidentified PFAS, thus, pyrolysis gas chromatography-mass spectrometry was used to provide evidence of the nature of the non-extractable fluorine present in the ski wax products. [Display omitted] •PFAS profile among the ski wax products varies between manufacturers.•Analysis of EOF and TF by CIC aid to estimate the total PFAS burden.•Complementary techniques such as ICP-MS or 19F NMR have shown potential for the determination of F.•Pyrolysis GC-MS was used to study the nature of the non-extractable fluorine present in the ski wax products.•The developed multi-platform approach provides a more holistic perspective on the PFAS and F content in ski wax products.