Assessing per- and polyfluoroalkyl substances in globally sourced food packaging

Analysis of neutral per- and polyfluoroalkyl substances (PFAS) by gas chromatography ‒ high resolution mass spectrometry (GCHRMS)

Most of the studies on per- and polyfluoroalkyl substances (PFAS) to date encompass water soluble and ionic PFAS analyzed by liquid chromatography ̶ mass spectrometry, yet analytical methods and information on the occurrence of neutral PFAS are lacking. To this aim, we developed a new method for analysis of forty neutral PFAS using gas chromatography (GC) ̶ Orbitrap mass spectrometry with electron ionization (EI). Analytes were comprised of 29 fluorotelomer alcohols, 6 fluorotelomer acrylates and methacrylates, 3 perfluoroalkane sulfonamides and 2 perfluoroalkane sulfonamido alcohols. Gas chromatographic separation was developed on two GC phases: a standard non-polar (5 % diphenyl and 95 % dimethyl polysiloxane) and a mid-polar (6 % cyanopropylphenyl, 94 % dimethylpolysiloxane). A custom-made high-resolution mass spectral (HRMS) library was developed and used to evaluate PFAS accuracy of identification. Overall, 85 % of PFAS were correctly identified. A quantitative method was developed and evaluated for sensitivity, linearity, reproducibility, and ion interferences. Method sensitivity varied for different PFAS from 1 to 50 ppb based on the lowest calibrated levels. The developed method was utilized for analysis of PFAS in paper-based food contact materials after developing and evaluating the extraction protocol. Method applicability was demonstrated by analyzing paper-based food packaging samples, where 6:2 fluorotelomer alcohol was detected and measured at levels up to 351 ng/g. The developed GCHRMS method can be utilized for identification and measurement of neutral PFAS in various matrices, including food, dust, food contact materials, textiles and others.

Perfluoroalkyl acids (PFAAs) and their precursors in sediments and adjacent riparian soils from the Three Gorges Reservoir, China: Contamination characteristics, source apportionment and ecological risks

Information on the occurrence and spatial distribution of perfluoroalkyl acids (PFAAs) and their precursors in sediments and adjacent riparian soils of Three Gorges Reservoir (TGR), which is one of the largest reservoirs in the world, is still limited. In this study, The total concentrations of these per- and polyfluoroalkyl substances (PFASs) ranged from 2220 to 19,300 pg/g in sediments and 298-9540 pg/g in soils. PFOA was the dominant PFAS in sediments and soils, accounting for 23.4% and 30.7% of the total median cocentrations of PFASs, respectively. PFAA precursors, such as 4:2 fluorotelomer sulfonate (4:2 FTS), 6:2 fluorotelomer sulfonate (6:2 FTS), and perfluorooctane sulfonamide (FOSA), were widely detected in sediments and soils. The distribution of PFASs exhibited distinct spatial variations and was more influenced by anthropogenic activities. Positive matrix factorization (PMF) identified fire-fighting foams (AFFF) and legacy fluoropolymer industry/textile treatment were the dominant sources in sediments (31.5%) and soils (30.8%), respectively. Finally, the ecological risk assessment showed that PFOS exhibited low to medium risks. Our findings indicate that the contamination of PFAA precursors must be considered when developing management measures to protect the TGR region.

The quest for the perfect "total PFAS" method: how can the total oxidisable precursor (TOP) assay be made reliable?

Per- and polyfluoroalkyl substances (PFAS) make up a large and complex class of manmade chemicals. They have been widely used in numerous industrial branches and are incorporated into many consumer products. Today, there is a consensus on the fact that PFAS are present in all environmental compartments and that populations all over the world are subjected to them via internal exposure. It has been estimated that thousands of individual PFAS have been manufactured and marketed since the 1950s, to which impurities present in commercial products and intermediate environmental transformation products should be added. Since it is unrealistic to be able to individually identify, detect and quantify all the PFAS present in a sample, several analytical approaches have been developed to assess the presence of "hidden/unseen" PFAS. One of these, known as the total oxidisable precursor (TOP) assay, was first described in 2012. Basically, it converts some PFAS, hereafter referred to as precursors, into stable terminal products readily measurable by routine target methods. This review is based on more than 100 studies in which the original TOP assay was simply applied or optimised. The review found that the TOP assay was selective, sensitive, applicable to many matrices, useful within a forensic context, inexpensive, and easy to implement and has been assessed in the literature on a wide range of precursors. However, this method comprises many subtleties and has some flaws that operators should be made aware of so that they may be addressed as far as possible. Finally, this review tries to lay the foundations for better practices and quality assurance/quality control measures, in order to improve accuracy and reliability of TOP assay results.

High-Resolution Mass Spectrometry for Identification, Quantification, and Risk Assessment of 40 PFAS Migrating from Microwave Popcorn Bags

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are widely utilized in food contact materials (FCMs) due to their water- and oil-repellent properties, yet their potential migration into food raises significant health concerns. This study employs high-resolution mass spectrometry (HRMS) to quantify the migration of 40 PFAS from microwave popcorn bags and assess the associated health risks. HRMS offers high mass accuracy and resolution, enabling precise detection of a broad spectrum of PFASs, including those with low migration levels. Migration experiments were conducted using 10% ethanol and 50% ethanol as food simulants at 70 °C for 2 h. The results indicate that when risk assessment is based solely on the European Food Safety Authority's (EFSA) tolerable weekly intake (TWI) for four PFAS, hazard ratio (HR) values range from 0.01 to 0.8, suggesting minimal risk. However, when all PFAS are converted into perfluorooctanoic acid equivalents (PEQs) and compared against the U.S. Environmental Protection Agency's (EPA's) reference dose (RfD), HR values range from 0.3 to 142.3, indicating a significantly elevated health risk. These findings emphasize the necessity of comprehensive risk assessments incorporating the cumulative effects of all PFAS to better understand potential human exposure and inform regulatory policies.

Per- and polyfluoroalkyl substances (PFAS) accumulation in fish occupying different trophic positions from East Canyon Creek, a seasonally effluent-dominated river, Utah, USA

Fish and seafood are considered a major source of human dietary exposure to per- and polyfluoroalkyl substances (PFAS). In this study, we examined levels of 35 PFAS in fish samples of brown trout and mottled sculpin, which occupy different trophic positions, collected in 2014 from East Canyon Creek in Utah, USA. We observed 20 PFAS with ∑20PFAS ranging from 0.46-63.9 ng/g and from Collapse

Key Words

• Bioaccumulation
• Fish
• Food safety
• PFAS
• Trophic position

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MESH Headings

• Animals
• Utah
• Water Pollutants, Chemical/metabolism
• Water Pollutants, Chemical/analysis
• Fluorocarbons/metabolism
• Fluorocarbons/analysis
• Environmental Monitoring
• Rivers/chemistry
• Food Chain
• Fishes/metabolism
• Trout/metabolism

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Affiliation(s)

Yelena Sapozhnikova USDA, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, USA.
Kevin M Stroski USDA, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, USA; Center for Reservoir and Aquatic Systems Research, Department of Environmental Science, Baylor University, Waco, TX, USA
Samuel P Haddad Center for Reservoir and Aquatic Systems Research, Department of Environmental Science, Baylor University, Waco, TX, USA
S Rebekah Burket Center for Reservoir and Aquatic Systems Research, Department of Environmental Science, Baylor University, Waco, TX, USA
Michael Luers Snyderville Basin Water Reclamation District, Park City, UT, USA
Bryan W Brooks Center for Reservoir and Aquatic Systems Research, Department of Environmental Science, Baylor University, Waco, TX, USA

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Unveiling per- and polyfluoroalkyl substances contamination in e-cigarette refill liquids: A comprehensive analytical assessment

A robust analytical method was developed for the determination of per- and polyfluoroalkyl substances (PFAS) in e-cigarette refill liquids using solid-phase extraction (SPE) with weak anion-exchange sorbent, followed by detection with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The design of experiment approach was employed to optimize sample preparation, leading to the validation of the method with limits of detection for PFAS ranging from 0.24 to 1.1 pg/mL. The method demonstrated inter-day repeatability of <17 % and relative recovery values between 89 % and 123 %. Additionally, the study explored the composition of e-cigarette refill liquids, focusing on the concentrations of primary constituents, such as vegetable glycerine and propylene glycol. Direct PFAS exposure through e-cigarette use might be of significant health concern due to vaping. Additionally, such products may serve as new source of PFAS release raising emerging issues about environment. Potential PFAS contamination in e-cigarette refill liquids may include manufacturing processes, packaging materials, or components of the e-cigarette devices, in result, leading to exposure during inhalation. A total of 31 e-cigarette refill liquid samples from various brands were analysed, revealing that PFAS were present mainly at trace levels. However, elevated concentrations exceeding 25 pg in 1 mL of commercial e-cigarette refill liquids were determined for PFNA, PFHxA, PFBS, HFPO-DA (GenX), and N-EtFOSAA. Among these, PFBS exhibited the highest detection frequency, occurring in 39 % of the samples. Notably, at least one of PFAS compounds was detected in 84 % of the samples analysed. Moreover, the higher PFAS content was determined in e-cigarette refill liquids with a nicotine content of 20 mg/mL than those with 6 mg/mL.

A systematic review for non-targeted analysis of per- and polyfluoroalkyl substances (PFAS)

This review follows the PRISMA guidelines to provide a systematic review of 115 peer reviewed articles that used non-targeted analysis (NTA) methods to detect per- and polyfluoroalkylated substances (PFAS). This literature highlights the significant positive impact of NTA in understanding PFAS in the environment. Within the literature a geographical bias exists, with most NTA studies (∼60 %) conducted in the United States and China. Future studies in other regions (such as South America and Africa) are needed to gain a more global understanding. More research is required in marine environments and the atmosphere, as current studies focus mainly on freshwater, groundwater, soil, and sediments. The majority of studies focus on measuring PFAS in the environment, rather than in commercial products (with the exception of AFFF). Non-lethal blood sampling has been successful for NTA in humans and wildlife, but additional biomonitoring studies are required on exposed cohorts to understand health risks and PFAS biotransformation pathways. NTA methods mostly use liquid chromatography and negative ionisation, which biases the literature towards the detection of specific PFAS. Despite improvements in data reporting and quality assurance and control (QA/QC) procedures, factors such as false negative and false positive rates are often overlooked, and many NTA workflows remain highly subjective. Perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) are the most detected PFAS classes, identified in over 80 % of NTA studies, and are common in routine monitoring. However, our review identified >1000 PFAS from a total of 382 different PFAS classes, with over 300 classes found in fewer than 5 % of studies. This highlights the variety of different PFAS present in the environment, and the limitations of relying solely on targeted methods. Future monitoring programs and regulations would benefit from considering NTA methods to provide more comprehensive information on PFAS present in the environment.

Spatial and seasonal distribution, sources, and health risks of PM2.5 loaded per- and polyfluoroalkyl substances (PFASs) in a typical megacity

Per- and polyfluoroalkyl substances (PFASs), a class of ubiquitous and emerging environmental pollutants, have garnered considerable attention due to the scarcity of knowledge regarding their atmospheric sources and the associated human health risks from aerosol exposure. This study investigated the spatial-temporal distribution and potential sources of PFASs in Nanjing city of eastern China by collecting 66 PM2.5 samples from industrial, urban, and rural areas between July 2022 and August 2023. Employing ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), 21 distinct PFASs were detected with concentrations ranging from 9.62 to 136 pg·m-3, predominantly higher in urban areas. Airborne PFASs concentrations exhibited seasonal fluctuations, with the highest levels observed in autumn, followed by spring, summer and winter. Diagnostic ratio and positive matrix factorization (PMF) for source analyses revealed the significant influence of long-range transport, the textile and paper packaging industry, and the decomposition of fluorochemical precursors were identified as the main contributors, accounting for 18.2 %, 15.8 %, and 16.1 % respectively. Population exposure was evaluated through deposition and dermal penetration modeling, with inhalation intake estimated at 2.05 pg·kg-1·d-1 and dermal contact intake at 1.01 pg·kg-1·d-1. Among the 21 assessed PFASs, perfluoro-n-hexanoic acid (PFHxA) was identified posing the most significant risk regarding respiratory effects, skin sensitization, and carcinogenic potential. This research provides critical insights into the spatial and seasonal distribution of atmospheric PFASs and the assessment of combined human exposure risks in rapidly developing areas.

Release of Volatile Per- and Polyfluoroalkyl Substances from Plant Fiber-Based Food Packaging and Municipal Solid Waste to Gas under Simulated Landfill Conditions

Per- and polyfluoroalkyl substances (PFAS) have been detected in plant fiber-based food packaging and most such packaging is disposed in landfills. The objective of this research was to evaluate the release of volatile PFAS to the gas-phase from PFAS-containing, single-use food packaging materials and from municipal solid waste (MSW) during anaerobic decomposition under simulated landfill conditions. After screening 46 materials for total F and 6:2 fluorotelomer alcohol (FTOH), packaging materials were classified as high or low F. High F materials included microwavable popcorn bags, natural plates, compostable bowls, biodegradable boxes, bagasse containers and eco-friendly plates, while the low F materials tested were paper plates, eco-friendly food trays and poly coated freezer paper. Summed PFAS release from the high F materials was 62-800 ng PFAS/g sample and 6:2 FTOH comprised 96.8-99.9% of the summed PFAS. The low F materials and MSW released 0.1-0.4 ng summed PFAS/g sample and 7:2-secondary (s) FTOH was the dominant volatile PFAS. PFAS were generally released early in the 123-285-day decomposition cycle, suggesting that some PFAS will be released prior to the installation of landfill gas collection systems. Nonetheless, PFAS have been reported in collected landfill gas, indicating that release occurs over many years.

A portable fluorescence sensing system for timely onsite perfluorooctane sulfonate detection based on an aggregate induced emission fluorescence sensor

Perfluorooctane sulfonate (PFOS), a ubiquitous persistent organic pollutant, has aroused growing concern due to its adverse effects on human health. Timely onsite monitoring of PFOS in heavily contaminated areas is crucial for effective pollution management and prevention of its spread. However, relevant PFOS detection methods have rarely been reported. Herein, we developed a fluorescence sensing system capable of achieving timely onsite detection of PFOS under outdoor conditions. First, aggregate induced emission (AIE) fluorescence sensors, TPE-PAs, were synthesized. The optimized sensor could selectively interact with PFOS through electrostatic attraction and hydrogen bonding and exhibited prominent fluorescence enhancement after treating with PFOS. There was a good linear relationship between the fluorescence enhancement and PFOS concentration in the range of 0.05-30 ppm, and the limit of detection was measured to be 0.047 ppm. In addition, owing to the AIE fluorescence mechanism and high concentration of TPE-PAs in the sensing medium, the sensor demonstrated excellent anti-interference performance. Second, we developed a portable fluorometer, by modifying the power supply and sample cell of a tiny fluorometer, and further integrated this modified fluorometer, the prepared fluorescence sensor, standard PFOS solutions and other consumables into a portable test system. This test system showed good detection accuracy and reliability and successfully achieved timely onsite PFOS detection in real water samples.

Leaching of per- and polyfluoroalkyl substances (PFAS) from food contact materials with implications for waste disposal

Leaching of per- and polyfluoroalkyl substances (PFAS) during the post-consumer disposal of food contact materials (FCMs) poses a potential environmental threat but has seldom been evaluated. This study characterized the leaching behavior of PFAS and unidentified precursors from six common FCMs and assessed the impact of environmental conditions on PFAS release during disposal. The total concentration of 21 PFAS ranged from 3.2 to 377 ng/g in FCMs, with PFAS leachability into water varying between 1.1-42.8 %. Increasing temperature promoted PFAS leaching, with leached nine primary PFAS (∑9PFAS) reaching 46.3, 70.4, and 102 ng/L at 35, 45, and 55 ℃, respectively. Thermodynamic analysis (∆G>0, ∆H>0, and ∆S<0) indicated hydrophobic interactions control PFAS leaching. The presence of dissolved organic matter in synthetic leachate increased the leached ∑9PFAS from 47.1 to 103 ng/L but decreased PFBS, PFOS, and 6:2 FTS leaching. The total release of seven perfluorocarboxylic acids (∑7PFCAs) from takeaway food packaging waste was estimated to be 0.3-8.2 kg/y to landfill leachate and 0.6-15.4 kg/y to incineration plant leachate, contributing 0.2-4.8 % and 0.1-3.2 % of total ∑7PFCAs in each leachate type. While the study presents a refined methodology for estimating PFAS release during disposal, future research is needed on the indirect contribution from precursors.

Aggregated health risk assessment of perfluoroalkyl acids migrated from convenience food contact materials

Ingestion of perfluoroalkyl acids (PFAAs) via contaminated food contact materials (FCMs) is an important human exposure source. This study adopts a toxicity equivalent approach to evaluate the collective health risk of multiple PFAAs in FCMs. A comprehensive extraction and analysis of 21 PFAAs in FCMs was performed. Among the analyzed substances, 15 PFAAs were detected. Migration experiment using three food simulants revealed the migration range of seven PFAAs from FCMs into the simulant to be 0.47-46.7 ng/cm2. The hazard quotient results suggest minimal health risk, except for 9% of packaged samples where perfluorooctanoic acid (PFOA) poses a higher risk. Utilizing PFOA toxic equivalent concentrations, comprehensive risk calculations showed ∼77% of samples potentially posing elevated health risks due to PFAA exposure. This emphasizes the substantial contribution of PFAAs beyond PFOA and underscores the importance of considering them in related assessments. The aggregated risk assessment reflects actual exposure circumstances more accurately.

Novel pillar[n]arenes magnetic nanoparticles: Preparation and application in quantitative analysis of trace perfluorinated compounds from aqueous samples

BACKGROUND

Perfluorinated compounds (PFCs) are a class of widely manufactured and used emerging persistent pollutants. The recent discovered new class of macrocycles pillararenes have garnered significant attention for the applications in environmental pollutant adsorption, with abundant π electron cavities, a symmetrical rigid structure, and host-guest recognition capabilities.

RESULTS

In this work, we designed and synthesized novel cationic pillar [n]arenes magnetic nanoparticles (CWPA5@MNPs), and investigated its adsorption performance and mechanism as a type of new adsorbent for the enrichment of PFCs. The results indicate that CWPA5@MNPs exhibits selectively strong affinity for perfluorooctane sulfonate (PFOS) and long-chain (C9-C14) perfluorocarboxylic acids (PFCAs), with the adsorption efficiency exceeding 80 % within 12 min. The maximum adsorption capacity of CWPA5@MNPs for PFOS was measured to be 29.02 mg/g. CWPA5@MNPs can be rapidly isolated from the solution using external magnets, offering a quick and easy separation. Consequently, this study established a CWPA5@MNPs-assisted magnetic solid-phase extraction (MSPE) coupled with high-performance liquid chromatography-tandem mass spectrometry (CWPA5@MNPs-MSPE-HPLC-MS/MS) method for the rapid detection of trace levels of PFCs in environmental water samples. The analysis of 7 PFCs yielded recovery rates ranging from 86.1 % to 107.5 %, with intraday and interday relative standard deviations (RSD) of 3.6-6.4 % and 1.3-7.0 %, respectively.

SIGNIFICANCE AND NOVELTY

The study reveals the synthesis and application of novel cationic pillar [n]arenes magnetic nanoparticles (CWPA5@MNPs) as highly efficient adsorbents for selective perfluorinated compounds (PFCs) in water samples. It demonstrates the potential of the newly developed CWPA5@MNPs-MSPE-HPLC-MS/MS method for the quantitative analysis of PFCs in environment, with high sensitivity, accuracy and stability.

Suspect screening of per-and polyfluoroalkyl substances in paper by selective and non-selective extraction with UHPLC-Q orbitrap MS

Non-targeted analysis and suspect screening of per- and polyfluoroalkyl substances (PFAS) in various matrices have gained traction with advancements in accurate mass analytical instruments. This study employed ultra-high performance liquid chromatography coupled to quadrupole orbitrap high-resolution mass spectrometry for PFAS suspect screening of paper grades used in the paper recycling chain. The samples were prepared using two extraction techniques; selective accelerated solvent extraction with weak anionic exchange solid-phase extraction and non-selective ultrasonic-assisted extraction. A suspect screening protocol was established to tentatively identify suspected PFAS against spectral databases using a systematic approach of peak filtering and study-specific thresholds for reporting, linked to a confidence level. The possible prevalence of previously unreported PFAS in several paper materials across the various collection sites in the paper recycling chain was inferred by the common detection of short-chain polyfluoroalkyl ketones and diketones in the paper recycling chain. The suspect screening tentatively identified 41 unique PFAS, with 3 common to both pre-treatment techniques. The detection of unique PFAS by the two sample pre-treatment techniques highlighted the significance of both selective and non-selective extraction in PFAS screening endeavours. Further, it showed the importance of understanding the acquisition mechanisms employed in mass spectrometry where data-dependent acquisition triggered fragmentation in certain identified compounds, and not in others. The tentatively identified PFAS indicated that there were several previously unreported PFAS in the paper recycling chain and that additional studies were required to investigate their abundance, possible persistence, bioaccumulation and toxicity, in relation to their functional groups and carbon chains.

Use of Tox21 screening data to profile PFAS bioactivities on nuclear receptors, cellular stress pathways, and cytochrome p450 enzymes

Per- and poly-fluoroalkyl substances (PFAS) are synthetic chemicals widely used in commercial products. PFAS are a global concern due to their persistence in the environment and extensive associations with adverse health outcomes. While legacy PFAS have been extensively studied, many non-legacy PFAS lack sufficient toxicity information. In this study, we first analyzed the bioactivity of PFAS using Tox21 screening data surveying more than 75 assay endpoints (e.g., nuclear receptors, stress response, and metabolism) to understand the toxicity of non-legacy PFAS and investigate potential new targets of PFAS. From the Tox21 screening data analysis, we confirmed several known PFAS targets/pathways and identified several potential novel targets/pathways of PFAS. To confirm the effect of PFAS on these novel targets/pathways, we conducted several cell- and enzyme-based assays in the follow-up studies. We found PFAS inhibited cytochromes P450s (CYPs), especially CYP2C9 with IC50 values of < 1 µM. Considering PFAS affected other targets/pathways at > 10 µM, PFAS have a higher affinity to CYP2C9. This PFAS-CYP2C9 interaction was further investigated using molecular docking analysis. The result suggested that PFAS directly bind to the active sites of CYP2C9. These findings have important implications to understand the mechanism of PFAS action and toxicity.

Non-targeted analysis of per- and polyfluorinated substances in consumer food packaging

This study sought to develop a non-targeted workflow using high-resolution mass spectrometry (HRMS) to investigate previously unknown PFAS in consumer food packaging samples. Samples composed of various materials for different food types were subjected to methanolic extraction, controlled migration with food simulants and total oxidizable precursor (TOP) assay. The developed HRMS workflow utilized many signatures unique to PFAS compounds: negative mass defect, diagnostic breakdown structures, as well as retention time prediction. Potential PFAS features were identified in all packaging studied, regardless of food and material types. Five tentatively identified compounds were confirmed with analytical standards: 6:2 fluorotelomer phosphate diester (6:2 diPAP) and one of its intermediate breakdown products 2H-perfluoro-2-octenoic acid (6:2 FTUCA), perfluoropentadecanoic acid (PFPeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA). Longer perfluorocarboxylic acids including C17 and C19 to C24 were also found present within a foil sample. Concentrations of 6:2 FTUCA ranged from 0.78 to 127 ng g-1 in methanolic extracts and up to 6 ng g-1 in food simulant after 240 h migration test. These results demonstrate the prevalence of both emerging and legacy PFAS in food packaging samples and highlight the usefulness of non-targeted tools to identify PFAS not included in targeted methods.

Identification and quantification of per- and polyfluorinated alkyl substances (PFAS) migrating from food contact materials (FCM)

Per- and polyfluorinated alkyl substances (PFAS) can be added to food contact materials (FCM) to increase their water and/or grease repellent properties. Some well-known PFAS are perfluoroalkyl carboxylic acids (PFCA), perfluoroalkyl sulfonic acids (PFSA), and polyfluorinated telomer alcohols (FTOH). Due to the strength of the carbon-fluorine bond, PFAS are chemically very stable and highly resistant to biological degradation, posing a risk to human health and the environment. To examine the presence of PFAS in paper-based FCM, various samples were collected, including popcorn bags, muffin cups, and pizza boxes with high total organic fluorine (TOF) content from the Danish and Spanish markets. The FCM composition was characterised by FTIR. Quantification of some well-known PFAS such as PFCA, PFSA, and FTOH was performed in food simulants using LC-MS/MS, and in addition a non-targeted screening approach was performed by LC-Orbitrap-HRMS. Among analysed samples, the highest concentrations of PFAS were found in a muffin cup made of cellulose (PFCA ∼ 1.41 μg kg-1 food, FTOH ∼ 11.5 μg kg-1 food), and the results were used to estimate dietary exposures to PFAS migrated from this FCM. Compared to measured TOF value in this sample, the fluorine from all quantified PFAS accounted for only 0.6%. Thus, a more powerful analytical approach was used to further investigate PFAS occurrence in this sample. Using non-targeted screening, an additional twenty compounds were identified, among them five with confidence level 1 and ten with confidence level 2. Many of them were either fluorotelomer carboxylic acids or sulfonic acids or ether-containing compounds.

Analysis of per- and polyfluoroalkyl substances (PFAS) in raw materials intended for the production of paper-based food contact materials - evaluating LC-MS/MS versus total fluorine and extractable organic fluorine

Per- and polyfluoroalkyl substances (PFAS) analysis has become crucial due to their presence in the environment, their persistence and potential health risks. These compounds are commonly used in food contact materials (FCM) as a coating to provide water and grease-repellent properties. One of the pathways for PFAS to enter the human body is either through direct consumption of contaminated food or indirectly through migration from FCM into food. The purpose of this study was to investigate where the initial contamination of paper FCM occurs. We analysed paper material consisting of fresh fibre and secondary materials, intended to produce food packaging for the presence of PFAS. The samples were extracted and analysed for 23 different PFAS substances using the targeted approach with LC tandem mass spectrometry (LC-MS/MS). This analytical technique detects specific, easily ionisable PFAS with high sensitivity. However, one drawback of this approach is that it allows the identification of less than 1% of the PFAS known today. For this reason, we used combustion ion chromatography (CIC) to determine the content of extractable organic fluorine compounds (EOF) and compare it to the total fluorine content. The targeted analysis using LC-MS/MS measured an average sum concentration of PFAS of 0.17 ng g-1 sample. Our research shows that the primary PFAS contamination happens during the recycling process since all of the samples in which the targeted PFAS were measured belonged to the secondary material. The most frequently detected analytes were PFOA and PFOS, detected in 90% and 62% of the samples, respectively, followed by PFBS (in 29% of the samples). CIC showed that measured PFAS via LC-MS/MS amount to an average of 2.7 × 10-4% of total fluorine content, whereas the EOF was under the LOD in all of the measured samples. This result highlights the complexity of the accurate determination of PFAS compounds, displaying what kind of information the chosen methods provide.

Determination of per- and polyfluoroalkyl compounds in paper recycling grades using ultra-high-performance liquid chromatography-high-resolution mass spectrometry

Globally, per- and polyfluoroalkyl substances (PFAS)-related research on paper products has focused on food packaging with less consideration on the presence of PFAS at different stages of the paper recycling chain. This study analysed the prevalence of PFAS in paper grades used for the manufacture of recycled paperboard. The presence of PFAS was attributed to the use of PFAS-containing additives, consumer usage, exposure to packed goods as well as contamination during mingling, sorting, collection, and recovery of paper recycling material. Q Orbitrap mass spectrometry was used to analyse the paper samples after accelerated solvent extraction and solid phase extraction. The distribution and possible propagation of 22 PFAS were determined in pre-consumer, retail and post-consumer paper products. Post-consumer samples had the highest combined average concentration (ΣPFAS) at 213 ng/g, while the ΣPFAS in retail (159 ng/g) and pre-consumer samples (121 ng/g) was detected at lower concentrations. This study showed that waste collection and recycling protocols may influence PFAS propagation and that measures must be developed to minimise and possibly eliminate exposure opportunities.

Unveiling per- and polyfluoroalkyl substance contamination in Chinese paper products and assessing their exposure risk

The contamination characteristics, migration patterns and health risks of per- and polyfluoroalkyl substances (PFAS) were investigated in 66 Chinese paper products by using target and non-target screening methods. Among 57 target PFASs, 5 and 6 PFASs were found in the hygiene paper products ( Collapse

Key Words

• Migration
• Non-target analysis
• Paper products
• Per- and polyfluoroalkyl substances
• Risk assessment

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MESH Headings

• Humans
• Fluorocarbons/analysis
• Ethanol
• Food
• Food Safety
• China
• Alkanesulfonic Acids/analysis

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Affiliation(s)

Yan-Fei Chen SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, Guangzhou 510006, China
Ting Liu SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, Guangzhou 510006, China
Li-Xin Hu SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, Guangzhou 510006, China
Chang-Er Chen SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, Guangzhou 510006, China
Bin Yang SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, Guangzhou 510006, China.
Guang-Guo Ying SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, Guangzhou 510006, China

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Polyfluoroalkyl phosphate esters (PAPs) as PFAS substitutes and precursors: An overview

Polyfluoroalkyl phosphate esters (PAPs) are emerging substitutes for legacy per- and polyfluoroalkyl substances (PFAS), which are widely applied in consumer products and closely related to people's daily lives. Increasing concern has been raised about the safety of PAPs due to their metabolism into perfluorooctanoic acid (PFOA) and other perfluorinated carboxylates (PFCAs) in vivo. This review summarizes the current knowledge on PAPs and highlights the knowledge gaps. PAPs dominated the PFAS profiles in wastewater, sludge, household dust, food-contact materials, paper products, paints, and cosmetics. They exhibit biomagnification due to their higher levels in top predators. PAPs have been detected in human blood worldwide, with the highest mean levels being found in the United States (1.9 ng/mL) and China (0.4 ng/mL). 6:2 diPAP is the predominant PAP among all identified matrices, followed by 8:2 diPAP. Toxicokinetic studies suggest that after entering the body, most PAPs undergo biotransformation, generating phase Ⅰ (i.e., PFCAs), phase II, and intermediate products with toxicity to be verified. Several epidemiological and toxicological studies have reported the antiandrogenic effect, estrogenic effect, thyroid disruption, oxidative damage, and reproductive toxicity of PAPs. More research is urgently needed on the source and fate of PAPs, human exposure pathways, toxicity other than reproductive and endocrine systems, toxic effects of metabolites, and mixed exposure effects.

A critical review of perfluoroalkyl and polyfluoroalkyl substances (PFAS) landfill disposal in the United States

Landfills manage materials containing per- and polyfluoroalkyl substances (PFAS) from municipal solid waste (MSW) and other waste streams. This manuscript summarizes state and federal initiatives and critically reviews peer-reviewed literature to define best practices for managing these wastes and identify data gaps to guide future research. The objective is to inform stakeholders about waste-derived PFAS disposed of in landfills, PFAS emissions, and the potential for related environmental impacts. Furthermore, this document highlights data gaps and uncertainties concerning the fate of PFAS during landfill disposal. Most studies on this topic measured PFAS in liquid landfill effluent (leachate); comparatively fewer have attempted to estimate PFAS loading in landfills or other effluent streams such as landfill gas (LFG). In all media, the reported total PFAS heavily depends on waste types and the number of PFAS included in the analytical method. Early studies which only measured a small number of PFAS, predominantly perfluoroalkyl acids (PFAAs), likely report a significant underestimation of total PFAS. Major findings include relationships between PFAS effluent and landfill conditions - biodegradable waste increases PFAS transformation and leaching. Based on the results of multiple studies, it is estimated that 84% of PFAS loading to MSW landfills (7.2 T total) remains in the waste mass, while 5% leaves via LFG and 11% via leachate on an annual basis. The environmental impact of landfill-derived PFAS has been well-documented. Additional research is needed on PFAS in landfilled construction and demolition debris, hazardous, and industrial waste in the US.

Per- and polyfluoroalkyl substances (PFAS) measured in seafood from a cross-section of retail stores in the United States

Seafood is a dominant source of human exposure to per- and polyfluoroalkyl substances (PFAS). Existing studies on foodborne PFAS exposure have focused on only a subset of these compounds. Here, we conducted a pilot study to screen 33 PFAS in 46 seafood samples from a cross-section of national and local stores in the US. Low levels of 8 PFAS were measured in 74% of the samples, predominated by PFHxS (59%). Total PFAS ranged between 0.12 and 20 ng/g; highest levels were measured in Estonia-sourced smelt. The highest median levels were of PFOA (0.84 ng/g) with elevated concentrations found in Chinese clams (2.4 ng/g), which exceeds the EU established maximum limits (MLs). Measured levels of PFHxS, PFOA, and PFNA also exceeded MLs in 24%, 7%, and 5% of the samples, respectively. For average consumption levels, exposures were below the EU established tolerable weekly intakes (TWIs). However, for more frequent consumption of flounder, catfish, and cod, exposures exceeded regulations, which warrants identifying vulnerable high seafood consuming populations. Accidental PFBS cross contamination from sample storage bags resulted in 100% detection in samples, highlighting the problem with post-purchase food handling practices such as storage and cooking that could also have a substantial impact on human exposure, potentially in larger amounts than the (sea)food itself.