Communicating Confidence of Per- and Polyfluoroalkyl Substance Identification via High-Resolution Mass Spectrometry

Environmental Science & Technology Letters, Год журнала: 2022, Номер 9(6), С. 473 - 481

Опубликована: Май 26, 2022

Per- and polyfluoroalkyl substances (PFASs) are important environmental contaminants, yet relatively few analytical reference standards exist for this class. Nontarget analyses performed by means of high-resolution mass spectrometry (HRMS) increasingly common the discovery identification PFASs in biological samples. The certainty PFAS identifications made via HRMS must be communicated through a reliable harmonized approach. Here, we present confidence scale along with criteria specific to suspect or nontarget analysis HRMS. Confidence levels range from level 1a─"Confirmed Reference Standard," 1b─"Indistinguishable 5─"Exact Masses Interest," which identified screening data filtering, two forms feature prioritization. This is consistent general communicating small organic molecules (e.g., match standards, library MS/MS, and/or retention times) but incorporates conventions tools used classification detection homologous series ranges defects). Our clarifies and, doing so, facilitates more efficient identification.

Язык: Английский

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Multicomponent PFAS sorption and desorption in common commercial adsorbents: Kinetics, isotherm, adsorbent dose, pH, and index ion and ionic strength effects

The Science of The Total Environment, Год журнала: 2023, Номер 904, С. 166568 - 166568

Опубликована: Авг. 24, 2023

The adsorption and desorption of 9 PFAS, including 3 perfluoroalkyl sulphonic 6 carboxylic acids, in artificial groundwater was investigated using commercial adsorbents that comprised a powdered activated carbon (PAC), surface-modified organoclay (NMC+n), carbonaceous organic amendment (ROAC). Sorption kinetics isotherms as well the effects adsorbent dose, pH, index ion ionic strength on PFAS were investigated. multicomponent rapid, especially for NMC+n ROAC, regardless chain length. sorption (and especially) impacted by ion, simulated groundwater, short with only minimal impacts PAC compared to ROAC. Although potential mineral charged constituents contributed through electrostatic interactions, these interactions susceptible variable chemistry. Hydrophobic also played major role facilitating increasing sorption, aliphatic functional groups. from below 8 % when aqueous phase deionised water, no measurable NMC+n. In contrast, increased substantially (30-100 %) adsorbents, ROAC NMC+n, but more so general, three exhibited strong stability long reversibility under different pH composition groundwater. This study highlights importance understanding not which may be useful decision making during ex-situ in-situ treatment PFAS-contaminated

Язык: Английский

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Solvent-Free Nonthermal Destruction of PFAS Chemicals and PFAS in Sediment by Piezoelectric Ball Milling

Environmental Science & Technology Letters, Год журнала: 2023, Номер 10(2), С. 198 - 203

Опубликована: Янв. 9, 2023

Studies on the destruction of solid per- and polyfluoroalkyl substances (PFAS) chemicals PFAS-laden wastes significantly lag behind urgent social demand. There is a great need to develop novel treatment processes that can destroy nonaqueous PFAS at ambient temperatures pressures. In this study, we piezoelectric-material-assisted ball milling (PZM-BM) process built principle collisions during activate PZMs generate ∼kV potentials for in absence solvents. Using boron nitride (BN), typical PZM, as an example, successfully demonstrate complete near-quantitative (∼100%) defluorination PFOS perfluorooctanoic acid (PFOA) after 2 h treatment. This was also used treat PFAS-contaminated sediment. Approximately 80% 21 targeted were destroyed 6 The reaction mechanisms determined be combination piezo-electrochemical oxidation fluorination BN. PZM-BM demonstrates many potential advantages, degradation diverse independent functional group chain configurations does not require caustic chemicals, heating, or pressurization. pioneering study lays groundwork optimizing various wastes.

Язык: Английский

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A review of the occurrence and microbial transformation of per- and polyfluoroalkyl substances (PFAS) in aqueous film-forming foam (AFFF)-impacted environments

The Science of The Total Environment, Год журнала: 2024, Номер 927, С. 171883 - 171883

Опубликована: Март 24, 2024

Язык: Английский

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Widening the Lens on PFASs: Direct Human Exposure to Perfluoroalkyl Acid Precursors (pre-PFAAs)

Environmental Science & Technology, Год журнала: 2022, Номер 56(10), С. 6004 - 6013

Опубликована: Март 24, 2022

Determining health risks associated with per-/polyfluoroalkyl substances (PFASs) is a highly complex problem requiring massive efforts for scientists, risk assessors, and regulators. Among the most poorly understood pressing questions relative importance of pre-PFAAs, which are PFASs that degrade to persistent perfluoroalkyl acids. How many vast number existing pre-PFAAs relevant direct human exposure, what predominant exposure pathways? What evidence provided by biomonitoring studies? important their biotransformation products assessment? This article outlines recent progress recommendations toward widening lens on PFAS include pre-PFAA subclass.

Язык: Английский

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Microbial biotransformation of aqueous film-forming foam derived polyfluoroalkyl substances

The Science of The Total Environment, Год журнала: 2022, Номер 824, С. 153711 - 153711

Опубликована: Фев. 8, 2022

Язык: Английский

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Role of Mineral–Organic Interactions in PFAS Retention by AFFF-Impacted Soil

Environmental Science & Technology, Год журнала: 2023, Номер 57(13), С. 5231 - 5242

Опубликована: Март 22, 2023

A comprehensive, generalized approach to predict the retention of per- and polyfluoroalkyl substances (PFAS) from aqueous film-forming foam (AFFF) by a soil matrix as function PFAS molecular physiochemical properties was developed. An AFFF with 34 major (12 anions 22 zwitterions) added uncontaminated in one-dimensional saturated column experiments mass retained measured. described using an exhaustive statistical generate poly-parameter quantitative structure–property relationship (ppQSPR). The relevant predictive were molar mass, fluorine, number nitrogens molecule, poorly crystalline Fe oxides, organic carbon, specific (BET-N2) surface area. anionic nearly independent largely hydrophobicity, size fluorinated side chain main predictor. Retention nitrogen-containing zwitterionic related metal oxides carbon content. Knowledge extent which suite may respond variations properties, developed here, paves way for development reactive transport algorithms ability capture dynamics source zones over extended time frames.

Язык: Английский

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Nontarget Identification of Novel Per- and Polyfluoroalkyl Substances (PFAS) in Soils from an Oil Refinery in Southwestern China: A Combined Approach with TOP Assay

Environmental Science & Technology, Год журнала: 2023, Номер 57(48), С. 20194 - 20205

Опубликована: Ноя. 22, 2023

Oil refinery activity can be an emission source of perfluoroalkyl and polyfluoroalkyl substances (PFAS) to the environment, while contamination profiles in soils remain unknown. This study investigated 44 target PFAS soil samples collected from oil Southeastern China, identified novel PFAS, characterized their behaviors by assessing changes before after employing advanced oxidation using a combination nontarget analysis total oxidizable precursor (TOP) assay. Thirty-four were detected samples. Trifluoroacetic acid (TFA) hexafluoropropylene oxide dimer (HFPO-DA) dominant PFAS. Twenty-three 14 classes identified, including 8 precursors, 11 products, 4 stable TOP Particularly, three per-/polyfluorinated alcohols for first time, hexafluoroisopropanol (HFIP) quantified up 657 ng/g dw is TFA. Bistriflimide (NTf2) potentially associated with was also reported time highlighted advantage embedding assay reveal not only presence unknown but roles environmental processes. Overall, this approach provides efficient way uncover especially source-impacted areas.

Язык: Английский

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Influence of grain size, organic carbon and organic matter residue content on the sorption of per- and polyfluoroalkyl substances in aqueous film forming foam contaminated soils - Implications for remediation using soil washing

The Science of The Total Environment, Год журнала: 2023, Номер 875, С. 162668 - 162668

Опубликована: Март 8, 2023

A soil that was historically contaminated with Aqueous Film Forming Foam (AFFF) dry sieved into size fractions representative of those produced during washing. Batch sorption tests were then conducted to investigate the effect parameters on in situ per- and polyfluoroalkyl substances (PFAS) these different fractions: < 0.063 mm, 0.5 2 4 8 organic matter residues (SOMR). PFOS (513 ng/g), 6:2 FTS (132 ng/g) PFHxS (58 most dominant PFAS AFFF soil. Non-spiked, Kd values for 19 ranged from 0.2 138 L/Kg (log −0.8 2.14) bulk dependant head group perfluorinated chain length (spanning C4 C13). The increased decreasing grain increasing carbon content (OC), which correlated each other. For example, value silt clay (< 17.1 L/Kg, log 1.23) approximately 30 times higher compared gravel fraction (4 0.6 −0.25). highest (116.6 2.07) found SOMR fraction, had OC content. Koc 6.9 0.84) 1906 3.28) clay, indicating mineral composition also influenced sorption. results here emphasize need separate coarse-grained fine-grained fractions, particular SOMR, optimize washing process. Higher smaller indicate coarser soils are better suited

Язык: Английский

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The Total Oxidizable Precursor (TOP) Assay as a Forensic Tool for Per- and Polyfluoroalkyl Substances (PFAS) Source Apportionment

ACS ES&T Water, Год журнала: 2023, Номер 4(3), С. 948 - 957

Опубликована: Июль 5, 2023

Per- and polyfluoroalkyl substances (PFASs) are a class of synthetic, organic chemicals that contaminate drinking water natural ecosystems. PFAS source apportionment is challenging because there many sources, standard analytical methods quantify fewer than 100 the thousands PFASs in commerce. The total oxidizable precursor (TOP) assay augments number can be quantified increasingly incorporated into routine site investigation. Here we examine ability TOP to identify including aqueous film-forming foam (AFFF) impacted sites, municipal wastewater treatment plants (WWTPs), solid waste landfills 145 samples from 46 locations three countries. bootstrapped mean composition each was dominated by precursors, particularly WWTPs where precursors form short-chain perfluoroalkyl carboxylates during were most common. Compared when data excluded, inclusion dimension-reducing algorithms, such as principal component analysis (PCA), improved separation among sources. We converted PCA tool web application allows users initiate efforts on sites contaminant sources unknown.

Язык: Английский

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