Perfluoroalkyl acid precursor or weakly fluorinated organic compound? A proof of concept for oxidative fractionation of PFAS and organofluorines

Analytical and Bioanalytical Chemistry, Journal Year: 2024, Volume and Issue: 416(29), P. 6799 - 6808

Published: Oct. 12, 2024

Abstract Organofluorine mass balance approaches are increasingly applied to investigate the occurrence of per- and polyfluoroalkyl substances (PFAS) other organofluorines in environmental samples more comprehensively. Usually, complex prevent identification quantification every fluorine-containing molecule. Consequently, large unidentified fractions between fluorine sum parameters such as extractable organic (EOF) quantified analytes frequently reported. We propose using oxidative conversion separate (unidentified) weakly fluorinated compounds (e.g., pesticides, pharmaceuticals) from PFAA-precursors (perfluoroalkyl chain lengths ≥ C 6 ). show with three organofluorine model (flufenamic acid, diflufenican, pantoprazole) that CF 3 -groups or aromatic can be quantitatively converted inorganic fluoride trifluoroacetic acid (TFA) by applying PhotoTOP oxidation (UV/TiO 2 The principle separation mixtures is demonstrated together PFAA-precursor 6:2/6:2 fluorotelomer mercaptoalkyl phosphate diester (FTMAP). After oxidation, products F − TFA were separated PFCAs (> 4 ) SPE, analyzed individually. Closed balances both without addition matrix achieved. Eventually, was verified total measurements combustion ion chromatography (CIC). proposed methods should considered a proof concept potentially explain EOF, especially if low content pharmaceuticals, their transformation contribute largely EOF. Future studies needed applicability complexity samples. Graphical

Language: Английский

Quantification of Extractable Total Per- and Polyfluoroalkyl Substances in Water Using Persulfate Preoxidation, Solid Phase Extraction, and Chemical Defluorination with Sodium Biphenyl or Ion-Pair Formation with Methylene Blue

ACS ES&T Water, Journal Year: 2024, Volume and Issue: 4(11), P. 4806 - 4817

Published: Oct. 16, 2024

This research developed and optimized innovative, cost-effective methods to quantify extractable total per- polyfluoroalkyl substances (PFAS) in water, overcoming limitations of existing techniques by integrating persulfate preoxidation with subsequent solid phase extraction (SPE), followed chemical defluorination using sodium biphenyl (SBP assay) or ion-pair formation methylene blue (MB assay). Persulfate improved selectivity oxidizing interfering organofluorines anionic surfactants, while SPE concentrated PFAS removed impurities such as inorganic fluoride. Both the SBP MB assays exhibited high responses across various structures, except for some (ultra)short-chain PFAS. The refined assays, including SPE, achieved limits detection 0.016 μgF/L 0.2 assay, robust recoveries compounds synthetic water matrices. Analyses PFAS-contaminated real waters assay revealed concentrations 5.1 industrial wastewater 0.30 river matching those combustion ion chromatography (CIC), a current benchmark method. however, showed 1.9–3.1 times higher than CIC assays. exceeded sum individual quantified LC–MS, underscoring necessity identifying unknown

Language: Английский

Latest trends in the environmental analysis of PFAS including nontarget analysis and EOF-, AOF-, and TOP-based methodologies

Analytical and Bioanalytical Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 21, 2024

Language: Английский