Combined use of total fluorine and oxidative fingerprinting for quantitative determination of side-chain fluorinated polymers in textiles

Given their extensive production volumes and potential to form persistent perfluoroalkyl acids (PFAAs), there is concern surrounding the ongoing use of side-chain fluorinated polymers (SFPs) in consumer products. Targeted SFP quantification relies on matrix assisted laser desorption ionization-time-of-flight mass spectrometry, which suffers from poor accuracy and high detection limits. Alternatively, total fluorine (TF)-based methods can be used, but these approaches report concentrations on a “fluorine equivalent” basis (e.g. F/m2 in the case of textiles) and are incapable of elucidating structure/chain length, which is critical for predicting the identity and quantity of degradation products. Here a new method for comprehensive characterization of SFPs is presented, which makes use of the total oxidizable precursors assay for fingerprint-based structural elucidation, and combustion ion chromatography for TF quantification. When used in parallel, quantitative determination of SFPs (in units of mass of CnF2n+1/m2 textile) is achieved. Expressing SFP concentrations in terms of mass of side-chain (as opposed to fluorine equivalents) facilitates estimation of both the structure and quantity of PFAA degradation products. As a proof-of-principle, the method was applied to six unknown SFP-coated medical textiles from Sweden. Four products contained C6-fluorotelomer-based SFPs (concentration range 36-188 mg C6F13/m2), one contained a C4-sulfonamide-based SFP (718 mg C4F9/m2), and one contained a C8-fluorotelomer-based SFP (249 mg C8F17/m2).