Molecular characteristics of emerging perfluoroalkyl and polyfluoroalkyl substances (PFAS) and dissolved organic matter (DOM) in surface waters around fluorine-related industries in a Chinese Megacity.

Fluorine-related industrial discharges are the main source of per- and polyfluoroalkyl substances (PFAS) contamination in surrounding surface waters, but the long-term environmental impacts of their residual PFAS and the interactions between PFAS and dissolved organic matter (DOM) in field waters have rarely been discussed. In this study, the concentrations of 32 target PFAS were quantified, 50 PFAS were identified and semi-quantified by suspect and nontarget screening, and the molecular characteristics of DOM were analyzed in the surface water of Shanghai. Concentrations of ∑PFAS were 284 ∼ 3018 ng/L.

Development of a Nontargeted Algorithm for Per- and Polyfluoroalkyl Substances in the FT-ICR Mass Spectra of Complex Organic Mixtures.

The unrivaled mass resolving power and subppm mass error enable the application of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for nontargeted screening of per- and polyfluoroalkyl substances (PFAS). Few automated FT-ICR MS methods exist for nontargeted analysis of PFAS in solutions containing other dissolved organic matter. In this study, isotopic pattern analysis and dynamic homologous series inspection were complementarily employed in the FTMSDeu algorithm to simultaneously assign chemical formulas for PFAS and other organic molecules, with an overall assignment accuracy of 91.

Durable TiO Heterojunction Composite Membrane Encapsulating N-Doped Graphene Nanosheets for Efficient Electro-Oxidation of GenX and Other PFAS in Fluorochemical Wastewater.

Rational interfacial engineering design of an electrocatalyst, such as a heterojunction structure, can effectively enhance its catalytic activity. This study aims to address a critical challenge associated with the use of carbon material@TiO heterojunction composite electrodes for wastewater treatment─electrode stability over long-term operation. Herein, we report a highly stabilized interfacial engineering strategy, i.

Broad-spectrum capture of hundreds of per- and polyfluoroalkyl substances from fluorochemical wastewater.

Hundreds of per- and polyfluoroalkyl substances (PFAS) are present in fluorochemical production effluents, and existing adsorption devices are inadequate to address this PFAS challenge given their extreme structural diversity. Here, we achieve the broad-spectrum capture of 107 PFAS from fluorochemical effluents using a treatment-train strategy that combines Zn-based electrocoagulation (EC) with anion-exchange resin (AER) beds. The "zero-carbon" adsorbent, zinc hydroxide flocs generated insitu by Zn-based EC, bulk removes PFAS with log K > 4 through a semi-micellar adsorption mechanism similar to mineral flotation and achieves adsorption capacities at the optimal level of all reported adsorbents.

Nontarget Analysis and Characterization of a Group of Abundant Polyfluoroalkyl Substances─Fluorinated Benzoylurea Pesticides and Their Analogues and Transformation Products in Fish by LC-HRMS and Chemical Species-Specific Algorithms.

Poly- and perfluoroalkyl substances (PFASs) are a large class of fluorinated chemicals used in various industrial and agrochemical products such as fluorinated benzoylurea (FBU) pesticides. Initiated from an incidental and preliminary finding of three high-abundance FBUs in fish, this study implemented nontarget analysis and characterization for FBUs together with their analogues and transformation products (TPs) in fish using liquid chromatography, high-resolution mass spectrometry, and chemical species-specific algorithms. A total of 23 FBU-relevant compounds were found and tentatively/accurately elucidated with structures, including 18 PFASs and 5 non-PFAS compounds, of which 4 were original FBUs, 8 were FBU analogues, and 11 were FBU-TPs.

A comprehensive characterization biotransformation of chlorinated paraffin by human and carp liver microsomes via liquid chromatography-high-resolution mass spectrometry and screening algorithm.

The chlorinated paraffin (CP) monomer 1,2,5,6,9,10-Hexachlorodecane (CP-4) was subjected to in vitro biotransformation using human and carp liver microsomes. Five types of CP-4 metabolites (OH-, keto-, enol-, aldehyde- and carboxy-CP-4) were identified in human liver microsomer while only mono-OH-CP-4 was found in the carp liver microsomes. Kinetic studies revealed that the formation of mono-, di-, tri-hydroxylated CP-4, keto-, enol-, and aldehyde-CP-4 in human liver microsomes was best described by substrate inhibition models, whereas the formation of carboxylated CP-4 metabolites best fit the Michaelis-Menten model.

[Determination of 12 halogenated organic pollutants in edible fish by ultra performance liquid chromatography-high resolution mass spectrometry combined with ultrasound-assisted extraction and gel permeation chromatography purification].

Halogenated organic pollutants (HOPs) have attracted considerable attention owing to their persistence, bioaccumulation, and toxicity. The development of methods to detect HOPs in fish is challenging owing to the compositional complexity of fish matrices, which contain high levels of lipids and relatively low concentrations of HOPs. In addition, the lipophilicity of most HOPs renders their extraction difficult.

Nontarget analysis and characterization of p-phenylenediamine-quinones and -phenols in tire rubbers by LC-HRMS and chemical species-specific algorithm.

Background: N,N'-disubstituted p-phenylenediamine-quinones (PPDQs) are oxidization derivatives of p-phenylenediamines (PPDs) and have raised extensive concerns recently, due to their toxicities and prevalence in the environment, particularly in water environment. PPDQs are derived from tire rubbers, in which other PPD oxidization products besides reported PPDQs may also exist, e.g.

Effects of polymer matrix and temperature on pyrolysis of tetrabromobisphenol A: Product profiles and transformation pathways.

Plastics are crucial constituents in electronic waste (e-waste) and part of the issue in e-waste recycling and environmental protection. However, previous studies have mostly focused on plastic recovery or thermal behavior of flame retardants, but not both simultaneously. The present study simulated the process of e-waste thermal treatment to explore tetrabromobisphenol A (TBBPA) pyrolysis at various temperatures using polystyrene (PS), polyvinyl chloride (PVC), and e-waste plastics as polymer matrices.

Comprehensive characterization and prioritization of halogenated organic compounds in fish and their implications for exposure.

Fish are an important pollution indicator for biomonitoring of halogenated organic compounds (HOCs) in aquatic environments, and HOCs in fish may pose health threats to consumers. This study performed nontarget and comprehensive analyses of HOCs in fish from an e-waste recycling zone by gas chromatography-high-resolution mass spectrometry, and further prioritized their human exposure risks. A total of 1652 formulas of HOCs were found in the fish, of which 1222, 117, and 313 were organochlorines, organobromines, and organochlorine-bromines, respectively.

Nontarget Analysis and Comprehensive Characterization of Iodinated Polyfluoroalkyl Acids in Wastewater and River Water by LC-HRMS with Cascade Precursor-Ion Exclusions and Algorithmic Approach.

Poly- and perfluoroalkyl acids (PFAAs) are a large family of widespread contaminants of worldwide concern and well-known as "forever chemicals". Direct emission of PFAAs from the fluorochemical industry is a crucial source of PFAA pollutants in the environment. This study implemented nontarget analysis and comprehensive characterization for a category of new PFAA contaminants, i.

Nontarget and Comprehensive Analyses of Halogenated Organic Additives in Electrical Product Plastics by GC-NCI-Q-Orbitrap-HRMS and Cl/Br-Screening Algorithms.

Halogenated organic additives (HOAs) are used in plastic components of various electrical products, potentially causing detrimental effects on the eco-environment and humans. Besides reported HOAs, many unknown HOAs may be present in electrical product plastics and urgently require identification and characterization. This study performed nontarget analysis and comprehensive characterization of HOAs in three typical electrical product plastics by nontarget analysis using gas chromatography-negative chemical ionization-high-resolution mass spectrometry in association with in-house-developed chlorine/bromine-specific data-processing algorithms.

First Discovery of Iodinated Polyfluoroalkyl Acids by Nontarget Mass-Spectrometric Analysis and Iodine-Specific Screening Algorithm.

Per- and polyfluoroalkyl acids (PFAAs) including polyfluoroalkyl carboxylic acids and polyfluoroalkyl sulfonic acids are a large category of crucial environmental pollutants of global concern. Besides known PFAAs, numerous unknown species may exist in the environment, urgently needing discovery and characterization. This study implemented nontarget analysis for a group of novel PFAA pollutants, viz.

Nontarget analysis and characterization of alkylamides in electrical product plastics by gas chromatography-positive chemical ionization quadrupole-orbitrap high-resolution mass spectrometry and quasi-molecular ion screening and anchoring algorithm.

Alkylamides are used as plastic additives in various materials and products, potentially posing risks to human health and the environment. Besides reported alkylamides in plastics, many unknown alkylamides may exist in various plastics, which are needing identification and characterization. This study performed nontarget analysis of alkylamides in electrical product plastics by gas chromatography-positive chemical ionization high-resolution mass spectrometry in full scan mode and an in-house developed data-processing algorithm.

Multi-residue determination of bisphenol analogues in organism tissues by ultra-high performance liquid chromatography-tandem mass spectrometry.

A reliable and sensitive analyzing method was developed and validated for determination of 13 novel bisphenol analogues (BPs) along with bisphenol A (BPA) in organism tissues. The complex organism tissues were treated by ultrasonic-assisted extraction using acetonitrile/formic acid (99:1, v/v), followed by successive purification using enhanced matrix removal-lipid sorbents and primary secondary amine sorbents. The BPs were finally determined by ultra-high performance liquid chromatography-tandem mass spectrometry after derivatization using pyridine-3-sulfonyl chloride.

Nontarget analysis and comprehensive characterization of halogenated organic pollutants by GC-Q-Orbitrap-HRMS in association with chromatogram segmentation and Cl/Br-specific screening algorithms.

Nontarget analysis enables high-efficiency screening and identification of halogenated organic pollutants (HOPs) in complex matrices irrespective of lacking authentic standards, particularly for novel and emerging species, thereby realizing comprehensive component characterization of HOPs. Notwithstanding, nontarget analysis and comprehensive characterization of HOPs remain on the way to improvement. In this study, we implemented nontarget analysis of HOPs in fly ash, egg and sediment using gas chromatography quadrupole-orbitrap high-resolution mass spectrometry with the aid of chromatogram segmentation and Cl/Br-specific screening algorithms, and further performed comprehensive characterization of components and distribution of HOPs.

High-performance nontarget analysis of halogenated organic compounds in tap water, fly ash, soil and sediment using ultrahigh resolution mass spectrometry and scripting approaches based on Cl/Br-specific search algorithms.

Halogenated organic compounds (HOCs) are a huge group of pollutants, which have caused severe environmental pollution worldwide. This study developed a nontarget analysis method for characterization of known and unknown HOCs in tap water, fly ash, soil and sediment using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) with aid of scripting data-processing approaches. The FT-ICR-MS was equipped with an electrospray ionization source operated in negative ion mode, and full scan at a mass resolution around 200,000 was applied.

Chlorine isotope analysis of polychlorinated organic pollutants using gas chromatography-high resolution mass spectrometry and evaluation of isotope ratio calculation schemes by experiment and numerical simulation.

Compound-specific isotope analysis of chlorine (CSIA-Cl) is a practicable and high-performance approach for revelation of transformation processes and source identification of chlorinated organic pollutants. This study conducted CSIA-Cl for typical polychlorinated organic pollutants using gas chromatography-high resolution mass spectrometry (GCHRMS) with an alternate injection mode using perchloroethylene (PCE) and trichloroethylene (TCE) as model analytes. PCE and TCE standards from two manufacturers were employed for method development, and chlorine isotope ratio calculation schemes were evaluated by experiment and numerical simulation.

Characterization of Compound-Specific Chlorine Isotopologue Distributions of Polychlorinated Organic Compounds by GC-HRMS for Source Identification.

Distributions of chlorine isotopologues are potentially a fingerprint feature of organochlorines. However, the exact distributions remain little known. This study measured compound-specific chlorine isotopologue distributions of six polychlorinated organic compounds (POCs) for source identification.

Are chlorine isotopologues of polychlorinated organic pollutants binomially distributed? Theoretical evaluation, numerical simulation, experimental evidences and implications for chlorine isotope analysis and source identification.

Relative abundances of chlorine isotopologues of polychlorinated organic compounds (POCs) are commonly recognized to comply with binomial distribution. This study investigated whether chlorine isotopologue distributions of polychlorinated organic pollutants are binomial and evaluated implications of the distributions to relevant analytical and environmental research by theoretical derivation, numerical simulation and experiment. Chlorine kinetic isotope effects and equilibrium isotope effects vary in stepwise chlorination reactions, leading to inconsistent chlorine isotope ratios on different reaction positions of products, which results in non-binomial chlorine isotopologue distributions of the products.

Defect Engineering on a TiO Electrode by Ce Doping for the Efficient Electrooxidation of Perfluorooctanesulfonate.

Defect engineering in an electrocatalyst, such as doping, has the potential to significantly enhance its catalytic activity and stability. Herein, we report the use of a defect engineering strategy to enhance the electrochemical reactivity of TiO through Ce doping (1-3 at. %), resulting in the significantly accelerated interfacial charge transfer and yielding a 37-129% increase in the anodic production of the hydroxyl radical (OH).

Energy-dependent normal and unusually large inverse chlorine kinetic isotope effects of simple chlorohydrocarbons in collision-induced dissociation by gas chromatography-electron ionization-tandem mass spectrometry.

Kinetic isotope effects (KIEs) occurring in mass spectrometry (MS) can provide in-depth insights into the fragmentation behaviors of compounds of interest in MS. Yet, the fundamentals of KIEs in collision-induced dissociation (CID) in tandem mass spectrometry (MS/MS) are unclear, and information about chlorine KIEs (Cl-KIEs) of organochlorines in MS is particularly scarce. This study investigated the Cl-KIEs of dichloromethane, trichloroethylene, and tetrachloroethylene during CID using gas chromatography-electron ionization triple-quadrupole MS/MS.

Ascertaining Hydrogen-Abstraction Reaction Efficiencies of Halogenated Organic Compounds in Electron Impact Ionization Processes by Gas Chromatography-High-Resolution Mass Spectrometry.

H-Abstraction reactions occurring during electron impact ionization processes in electron ionization mass spectrometry (EI-MS) are a long-standing and crucial topic in MS research. Yet, some critical relevant mechanisms are controversial and ambiguous, and information about the EI-induced H-abstraction reactions of halogenated organic compounds (HOCs) is completely in the dark. This study provides a systematic investigation of H-abstraction reactions of HOCs taking place in the EI source using C-hexachlorobenzene (C-HCB) and C-hexabromobenzene (C-HBB) as exemplary compounds by gas chromatography (GC)-high-resolution mass spectrometry (GC-HRMS).

Theoretical evaluation of inter-ion and intra-ion isotope effects in fragmentation: insights into chlorine and bromine isotope effects of halogenated organic compounds occurring in electron ionization mass spectrometry.

Revelation of chlorine and bromine isotope effects in fragmentation is crucial for compound-specific isotope analysis of chlorine/bromine (CSIA-Cl/Br) using gas chromatography-electron ionization mass spectrometry (GC-EI-MS), but theoretical fundamentals of the isotope effects remain unclear. Herein, this study provides a theoretical basis for elucidating the details and implications of chlorine and bromine isotope effects occurring in dehalogenation reactions in EI-MS. Inter-ion and intra-ion isotope effects can occur in dehalogenation reactions in EI-MS, and affect chlorine/bromine isotope ratios.

Tissue Distribution, Growth Dilution, and Species-Specific Bioaccumulation of Organic Ultraviolet Absorbents in Wildlife Freshwater Fish in the Pearl River Catchment, China.

Tissue distributions and body-size dependent and species-specific bioaccumulation of 12 organic ultraviolet absorbents (UVAs) were investigated in 9 species of wildlife freshwater fish from the Pearl River catchment, South China. The concentrations of the 12 UVAs were from 109 to 2320 ng/g lipid weight in the fish tissue samples. The UVAs 2-hydroxy-4-methoxybenzophenone (BP-3), octocrylene (OCR), UV531, and 5 benzotriazole UV stabilizers (UVP, UV329, UV234, UV328, and UV327) were detected in more than half of the fish tissue samples.