Per- and polyfluoroalkyl substances (PFAS) form a large chemical group, but routine monitoring targets only a few well-known compounds such as perfluorooctane sulfonic acid (PFOS). To better understand the widespread occurrence of PFAS in Dutch surface waters, we performed target analysis using an expanded list of compounds, combined with extensive suspect and de novo non-target screening (SNTS) to explore unreported PFAS beyond the scope of conventional monitoring. Analyses were performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography-trapped ion-mobility time-of-flight mass spectrometry (LC-timsTOF-MS). Target analysis focused on 24 previously underreported sulfonamide-based PFASs, enabled by newly available analytical standards and 34 common PFASs, representing 58 compounds. Several N-alkyl perfluoroalkane sulfonamidoacetic acids, including MeFBSAA (up to 50 ng/L), were found. SPr-FHxSA (N-sulfo propyl perfluorohexane sulfonamide), associated with aqueous film-forming foams (AFFFs), was detected in five samples (0.14-1.99 ng/L). In total, 38 PFAS were identified by target analysis. Collision cross-section (CCS) values of analytical standards were measured prior to SNTS. In SNTS, nineteen compounds, mainly fluorinated pharmaceuticals and pesticides, were identified at confidence level 2a using the MassBank library. Another 22 candidates were tentatively classified at levels 2b or 3, including an unsaturated PFOS analogue and a fluazinam transformation product, highlighting the ability of de novo SNTS to uncover unexpected PFAS. Finally, 6:2 fluorotelomer sulfonyl propanoamido-dimethylethyl sulfonate (6:2 FtSO2AoS) was confirmed at level 1a. Overall, integrating new PFAS standards with SNTS provided a far more complete view of PFAS presence in Dutch waters than target monitoring.

Per- and polyfluoroalkyl substances (PFAS) have been widely studied due to their persistence in the environment and potential risks to wildlife and human health. The identification and analysis of these thousands of compounds in various environmental matrices is crucial for assessing their presence and evaluating potential risks. However, the growing list of suspected PFAS necessitates the synthesis of pure standards, for the development and validation of analytical methods. This study describes the synthesis of ten sulfonamide-based PFAS precursors suspected to be in the environment potentially because of the use of aqueous film forming foams (AFFFs). Starting materials, delivered as isomer mixtures were purified by recrystallization using a benzylamine intermediate as a protecting group. The targeted compounds were obtained by alkylation of this benzyl intermediate followed by a deprotection step using hydrogen and a palladium catalyst. This method was evaluated on different PFAS classes. The ten synthesized compounds, including N-dimethylamminopropyl perfluoroalkane sulfonamides (AmPr-FASA) and N-trimethylammoniopropyl perfluoroalkane sulfonamides (PFASAmS), N-sulfopropyl perfluorohexane sulfonamide (SPr-FHxSA), N-dimethylaminopropyl perfluorohexane sulfonamidopropylsulfate (AmPr-FHxSAPS), N-perfluorobutane sulfonamide (FBSA) and N-perfluorobutane sulfonamidoethanol (FBSE) were characterized by NMR and HRMS. These reference materials will be valuable for developing and validating analytical methods for emerging PFAS in environmental samples.

Per- and polyfluoroalkyl substances (PFAS) are a large group of man-made compounds used, for example, as water and oil repellents to protect textiles and fabrics. Due to a growing concern about some of these compounds, industries have introduced new PFAS varieties with supposedly less harmful properties. In this study, different fabric samples from carpets, curtains and sofas (n = 30) were analyzed after a solvent extraction and an Envi-Carb clean-up for 81 PFAS, including legacy PFAS and 43 newly synthesized precursors, mainly perfluoroalkane sulfonamide derivatives by liquid and gas chromatography - mass spectrometry. In total, 28 PFAS were detected in the fabric samples. Fluorotelomer alcohols showed the highest concentrations in the fabrics (1-2329 μg/m2). Perfluoroalkyl sulfonic acids (PFSAs) and perfluoroalkyl acids (PFAAs) were also detected but at lower concentrations (e.g., 0.02-1.71 μg/m2 for PFHxA, 0.01-1.97 μg/m2 for PFBS). Perfluoroalkane sulfonamide precursors such as MeFBSAA, FBSE, MeFBSE, FBSA, and MeFBSEA were primarily found in carpet and curtain samples, accounting for approximately 10 % and 24 % of the total PFAS concentration in these matrices, respectively. These precursors were predominantly fully fluorinated compounds with 4-carbon chains. These precursors mostly correspond to fully fluorinated 4-carbon chain-PFAS and may be in accordance with the higher use of shorter PFAS compounds observed in recent years but more samples should be tested to confirm this assumption.

Perfluorooctane sulfonamide derivatives have been extensively used by industry for their surfactant properties and as building blocks for other perfluoroalkyl substances (PFAS). Due to their environmental impact and their potential degradation to other harmful PFAS, short-chain sulfonamide derivatives alternatives were introduced. However, these are now also suspected to be present in different environmental matrices and there is a lack of labelled and unlabelled reference standards to perform analyses. To address this gap, 40 native and deuterium labelled short-chain perfluoroalkane sulfonamide derivatives were synthesized, utilizing commercial perfluoroalkane sulfonyl fluoride as starting materials. All products were synthesized and then purified to obtain linear n-isomer reference standards. NMR, GC-FID-MS and LC-MS techniques were used for product identification and purity assessment. Recrystallization method was developed to selectively isolate the n-isomer from the isomer mixtures, thereby providing valuable reference and internal standards for environmental and toxicological investigations.

Monofluorinated polychlorinated biphenyls (fluoro-PCBs) have been prepared using the Suzuki-coupling, for use as analytical standards for PCB measurements. Seven of these fluoro-PCBs are analogues of the dioxin-like PCBs, listed by the WHO as the most toxic PCB congeners. Four highly chlorinated fluoro-PCBs have been prepared by Suzuki-coupling of 2,3,5,6-tetrachloro-bromoaniline with various substituted arylboronic acids. The resulting amino-fluoro-PCBs are chlorinated using the Sandmeyer reaction or deaminated to yield tetra-, penta- and hexa-chlorinated fluoro-PCBs. The fluoro-PCBs elute just before the corresponding PCBs in the GC chromatogram, which strongly indicates their potential as analytical standards.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Polybrominated diphenyl ethers (PBDEs) have become widely distributed as environmental contaminants due to their wide-spread use as flame retardants. Their structural similarity to other halogenated organic pollutants, for example polychlorinated biphenyls (PCBs), has led to speculation that they may have similar toxicological properties and effects. Recent focus on PBDEs as possible priority pollutants has also led to an increasing need for reference standards of PBDEs for toxicological studies and for environmental analysis. In this work we synthesized a series of fluorinated PBDEs (F-PBDEs) which can be used as possible internal standards, as an alternative to high-cost alternatives, such as the (13)C-labelled analogues. F-PBDEs have been synthesized by using different coupling reactions and by bromination of fluorinated starting materials.

Introduction Polybrominated diphenyl ethers (PBDEs) are globally distributed in the environment. They have been used as flame retardants for over 2 decades [1]. PBDEs have been found to bioaccumulate and there is also a concern about the health effects of PBDE exposure due to their potential endocrine disrupting properties. PBDEs are structurally similar to polychlorinated biphenyls (PCBs) and tend to concentrate in the lipid tissue. This has lead to extensive monitoring of PBDEs in all environmental matrices. The sample preparation and instrumental determination may lead to systematic and non-systematic (random) errors. It is generally accepted that the accurate determination of micro contaminants in such complex mixtures requires the use of internal standards (ISs). The benefit of using ISs with physico-chemical properties similar to those of the target compounds, is that both systematic and random errors will be minimized. Preliminary work on monofluorinated polycyclic aromatic hydrocarbons (F-PAHs) as ISs in gas chromatography (GC) is very promising [2], and therefore monofluorinated polybrominated diphenylethers (F-PBDE were synthesized [3] to determine if they could also be used as internal standards. F-PBDEs can be uses as internal standards for trace-level analysis of PBDEs and are alternatives to C-labelled analogues. The present study focused on the retention behavior of FPBDEs in GC, with the intention to use them as calibration standards for electron impact mass spectrometry (EI-MS) and GC-MS in the negative chemical ionisation mode (ECNI) GC-ECNIMS. Selected F-PBDEs can also be used as internal standards with GC-Electron Capture Detection (GC-ECD)