| 1. |
- Akhdhar, Abdullah, et al.
(author)
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The use of high resolution graphite furnace molecular absorption spectrometry (HR -MAS) for total fluorine determination in extractable organofluorines (EOF)
- 2020
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In: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 209
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Journal article (peer-reviewed)abstract
- The determination of total fluorine content using high-resolution graphite furnace continuum source molecular absorption spectrometry (HR- MAS) has been employed in a variety of samples for over 10 years. However, most of the samples analysed by HR-MAS are rich in fluoride, with negligible levels of organic fluorinated species. With an increase in concern surrounding per- and polyfluoroalkyl substances (PFASs), new methods to measure total fluorine of organofluorine using different techniques have been developed. However, no studies focused on PFASs behaviour in HR-MAS have been performed. As these compounds encompass a wide range of different structures, boiling points, decomposition temperatures and matrix interactions, a loss of accuracy can occur when an aqueous external calibration is performed using only one compound. To overcome this issue, an investigation into permanent modifiers for the graphite furnace was performed. After optimisation similar sensitivity for different PFCA was achieved when 400 mu g of W was used as a permanent modifier together with an optimised temperature program. The relative deviation between the different PFCA standard slopes relative to the PFOA slope was lower than 15%. The instrumental limit of detection and quantification (LOD and LOQ, respectively) of total fluorine as total PFCA was 0.1 mg L-1 and 0.3 mg L-1, respectively, while the method LOD and LOQ (using solid phase extraction) was 0.3 mu g L-1 and 1.0 mu g L-1, respectively. The developed method gave satisfactory recoveries for the spiked PFCA into seawater, river water and effluent using PFOA calibration standards. The optimised method is useful for measuring extractable organofluorines (EOF) when only ionic PFASs such as PFCA are expected. When other organofluorines are expected, the results using HR GF-MAS should be taken with caution.
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| 2. |
- Nascimento, Rodrigo A., et al.
(author)
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Sulfluramid use in Brazilian agriculture : A source of per- and polyfluoroalkyl substances (PFASs) to the environment
- 2018
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In: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 242, s. 1436-1443
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Journal article (peer-reviewed)abstract
- N-Ethyl perfluorooctane sulfonamide (EtFOSA) is a perfluorooctane sulfonate (PFOS) precursor and the active ingredient in sulfluramid, a pesticide which is used extensively in Brazil for management of leaf cutting ants. Here we investigate the occurrence of EtFOSA, PFOS, and other per- and polyfluoroalkyl substances (PFASs) in soil, eucalyptus leaves, water (ground, riverine, and coastal (estuarine/marine)) and coastal sediment from an agricultural region of Bahia State, Brazil. This area contains a larger number of eucalyptus plantations where sulfluramid is suspected to be applied. Soil, leaves, and coastal water (marine/estuarine) contained Sigma PFAS concentrations of up to 5400 pg g(-1), 979 pg g(-1), and 1020 pg L-1, respectively, with PFAS profiles generally dominated by PFOS and perfluorooctane sulfonamide (FOSA). Coastal sediment contained Sigma PFAS concentrations of up to 198 pg g(-1), with PFOS, FOSA, and perfluorooctanoic acid (PFOA) being the most frequently observed PFASs. These substances are all potential EtFOSA transformation products, pointing to sulfluramid as a possible source. In riverine water, Sigma PFAS concentrations of up to 8930 pg L-1 were observed. PFOS and PFOA were detected in all river water samples. Groundwater also exhibited PFAS contamination (5730 pg L-1 EPFAS5), likely from sulfluramid use. The observation of other PFASs (e.g. perfluorobutanoic acid) in freshwater suggests that other PFAS sources (in addition to sulfluramid) may be important in this region. Overall, these data support the hypothesis that sulfluramid use contributes to the occurrence of PFASs in the Brazilian environment.
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| 3. |
- Ruyle, Bridger J., et al.
(author)
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Interlaboratory Comparison of Extractable Organofluorine Measurements in Groundwater and Eel (Anguilla rostrata) : Recommendations for Methods Standardization
- 2023
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 57:48, s. 20159-20168
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Journal article (peer-reviewed)abstract
- Research on per- and polyfluoroalkyl substances (PFAS) frequently incorporates organofluorine measurements, particularly because they could support a class-based approach to regulation. However, standardized methods for organofluorine analysis in a broad suite of matrices are currently unavailable, including a method for extractable organofluorine (EOF) measured using combustion ion chromatography (CIC). Here, we report the results of an international interlaboratory comparison. Seven laboratories representing academia, government, and the private sector measured paired EOF and PFAS concentrations in groundwater and eel (Anguilla rostrata) from a site contaminated by aqueous film-forming foam. Among all laboratories, targeted PFAS could not explain all EOF in groundwater but accounted for most EOF in eel. EOF results from all laboratories for at least one replicate extract fell within one standard deviation of the interlaboratory mean for groundwater and five out of seven laboratories for eel. PFAS spike mixture recoveries for EOF measurements in groundwater and eel were close to the criterion (±30%) for standardized targeted PFAS methods. Instrumental operation of the CIC such as replicate sample injections was a major source of measurement uncertainty. Blank contamination and incomplete inorganic fluorine removal may introduce additional uncertainties. To elucidate the presence of unknown organofluorine using paired EOF and PFAS measurements, we recommend that analysts carefully consider confounding methodological uncertainties such as differences in precision between measurements, data processing steps such as blank subtraction and replicate analyses, and the relative recoveries of PFAS and other fluorine compounds.
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| 4. |
- Schellenberger, Steffen, et al.
(author)
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Release of Side-Chain Fluorinated Polymer-Containing Microplastic Fibers from Functional Textiles During Washing and First Estimates of Perfluoroalkyl Acid Emissions.
- 2019
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 53:24, s. 14329-14338
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Journal article (peer-reviewed)abstract
- The quantity and composition of fibers released from functional textiles during accelerated washing were investigated using the GyroWash method. Two fabrics [polyamide (PA) and polyester/cotton (PES/CO)] were selected and coated with perfluorohexane-based side-chain fluorinated polymers. Fibers released during washing ranged from ∼10 to 500 μ with a similar distribution for the two textile types. The PA-based fabric released considerably more fibers >20 μm in length compared to the PES/CO-based fabric (>1000/GyroWash for PA vs ∼200/GyroWash fibers for PES/CO). After one GyroWash (2-15 domestic washes), fibers that contained approximately 240 and 1300 μg total fluorine per square meter (μg F/m2) were released from the PA and PES/CO fabrics, respectively. Current understanding of the fate of microplastic fibers suggests that a large fraction of these fibers reach the environment either in effluent wastewater or sewage sludge applied to land. In the environment, the fluorinated side chains will be slowly cleaved from the backbone of the side-chain fluorinated polymers coated on the fibers and then transformed into short-chain perfluoroalkyl acids. On the European scale, emissions of up to ∼0.7 t of fluorotelomer alcohol (6:2 FTOH) per year were estimated for outdoor rain jackets treated with fluorotelomer-based side-chain fluorinated polymers.
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| 5. |
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| 6. |
- Schultes, Lara, 1989-
(author)
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Fluorine mass balance in wildlife and consumer products : How much organofluorine are we missing?
- 2019
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Doctoral thesis (other academic/artistic)abstract
- Per- and polyfluoroalkyl substances (PFASs) are a class of anthropogenic pollutants. Many PFASs are highly persistent and have been linked to adverse effects in humans. According to latest estimates, there are more than 4700 PFASs in global commerce, which poses immense challenges for environmental monitoring. This thesis aims at the development, validation and application of total fluorine (TF) and extractable organic fluorine (EOF) methods to consumer products and wildlife in order to estimate the fraction of unidentified organic fluorine in these samples via fluorine mass balance calculations.Fluoropolymer-coated food packaging materials and reference materials were used in paper I to validate and compare the performance of three different TF methods. Combustion ion chromatography (CIC), particle-induced gamma ray emission spectroscopy (PIGE) and instrumental neutron activation analysis (INAA) revealed excellent analytical agreement and precision under most circumstances. PIGE and INAA had the advantage of being non-destructive, while CIC was favored due to low detection limits. Fluorine mass balance experiments indicated large amounts of unidentified EOF and non-extractable fluorine. Paper II investigated the occurrence of PFASs, EOF and TF in cosmetic products from the Swedish market. In addition to extremely high concentrations (up to 470 µg/g) of polyfluoroalkyl phosphate diesters (diPAPs; perfluoroalkyl acid (PFAA) precursors), unintentionally-added PFAAs were found in a number of products, together with large amounts of unidentified organic fluorine. Human exposure estimates for perfluorooctanoate (PFOA) using the latest dermal uptake coefficients revealed that PFAA exposure via cosmetics may be significant. Paper III evaluated time trends of PFASs, EOF and TF in Baltic cod (Gadus morhua) from 1981 to 2013. Increasing trends were observed for the predominant PFAS perfluorooctane sulfonate (PFOS), as well as for C9-C12 perfluoroalkyl carboxylic acids (PFCAs) at rates of up to 7.7% per year. Declining concentrations were detected for the PFOS precursor perfluorooctane sulfonamide (FOSA), the EOF and its fraction not accounted for by target PFASs, while TF did not show any significant trends. The increasing concentrations of PFAAs despite their production phase-out could be attributed to either direct exposure of cod to legacy PFAAs or to indirect exposure via PFAA-precursor metabolism. Furthermore, negative correlations of certain PFASs with liver somatic index and body length were observed, which play an important role in the under-standing of toxicological effects of PFASs on wildlife. Paper IV studied the distribution of PFASs, EOF and TF in tissues from a Greenland killer whale (Orcinus orca). The sum of target PFAS concentrations was highest in liver (339 ng/g) and lowest in blubber (9.4 ng/g), consistent with other tissue distribution studies in marine mammals. In contrast, TF and EOF concentrations were highest in blubber (1315 and 229 ng/g, respectively), suggesting the presence of high concentrations of one or more presently unidentified fluorinated compounds. With the help of high resolution mass spectrometry-based suspect screening, several PFAS homologue series and individual PFASs not included in target analysis were detected.
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| 7. |
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| 8. |
- Schultes, Lara, et al.
(author)
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High Concentrations of Unidentified Extractable Organofluorine Observed in Blubber from a Greenland Killer Whale (Orcinus orca)
- 2020
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In: Environmental Science and Technology Letters. - : American Chemical Society (ACS). - 2328-8930. ; 7:12, s. 905-915
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Journal article (peer-reviewed)abstract
- It is generally accepted that per- and polyfluoroalkyl substances (PFASs) occur primarily in protein-rich tissues such as blood and liver, but few studies have examined the occurrence of legacy and novel PFASs in lipid-rich tissues such as blubber. Here we report the distribution of 24 PFASs, total fluorine, and extractable organic fluorine (EOF) in eight different tissues of a killer whale (Orcinus orca) from East Greenland. The sum of target PFAS concentrations was highest in liver (352 ng/g of wet weight) and decreased in the following order: blood > kidney ≈ lung ≈ ovary > skin ≈ muscle ≈ blubber. Most of the EOF consisted of known PFASs in all tissues except blubber, which displayed the highest concentration of EOF, almost none of which was attributed to targeted PFASs. Suspect screening using high-resolution mass spectrometry revealed the presence of additional PFASs but is unlikely to explain the high concentrations of EOF in blubber. While the identity of this unknown organofluorine and its pervasiveness in marine mammals require further investigation, this work suggests that exposure of killer whales to organofluorine substances may be underestimated by determination of legacy PFASs exclusively in liver or blood.
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| 9. |
- Schultes, Lara, et al.
(author)
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Per- and polyfluoroalkyl substances and fluorine mass balance in cosmetic products from the Swedish market : implications for environmental emissions and human exposure
- 2018
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In: Environmental Science. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 20:12, s. 1680-1690
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Journal article (peer-reviewed)abstract
- Per- and polyfluoroalkyl substances (PFASs) are a diverse class of >4700 chemicals used in commercial products and industrial processes. Concerns surrounding PFASs are principally due to their widespread occurrence in humans and the environment and links to adverse health effects. One of the lesser known uses for PFASs is in cosmetic products (CPs) which come into contact with the skin (e.g. hair products, powders, sunblocks, etc.). In the present work, thirty-one CPs from five product categories (cream, foundation, pencil, powder and shaving foam) were analyzed for 39 PFASs by liquid chromatography-tandem mass spectrometry, as well as extractable organic fluorine (EOF) and total fluorine (TF) by combustion ion chromatography (CIC). This multi-platform approach enabled determination of the fraction of fluorine accounted for by known PFASs (i.e. fluorine mass balance). Foundations and powders contained 25 different PFASs with the most frequently detected being perfluorinated carboxylic acids (perfluoroheptanoic acid and perfluorohexanoic acid) and polyfluoroalkyl phosphate esters (PAPs). sigma(14)PAP concentrations up to 470 g g(-1) were measured in products listing mixtures of PAPs as an ingredient. For all samples, sigma(39)PFAS concentrations only explained a small fraction of the EOF and TF, pointing to the presence of unknown organic and/or inorganic fluorinated substances, including polymers. While creams, pencil and shaving foams did not contain measurable concentrations of any of the 39 PFASs targeted here, CIC revealed high to moderate TF content. Overall, these data highlight the need for further investigations into the occurrence of PFASs in CPs and their importance with regards to human and environmental exposure.
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| 10. |
- Schultes, Lara, et al.
(author)
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Temporal Trends (1981-2013) of Per- and Polyfluoroalkyl Substances and Total Fluorine in Baltic cod (Gadus morhua)
- 2020
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In: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 39:2, s. 300-309
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Journal article (peer-reviewed)abstract
- Temporal trends from 1981 to 2013 of 28 per- and polyfluoroalkyl substances (PFASs) were investigated in liver tissue of cod (Gadus morhua) sampled near southeast Gotland, in the Baltic Sea. A total of 10 PFASs were detected, with n-ary sumation (28)PFAS geometric mean concentrations ranging from 6.03 to 23.9 ng/g ww. Perfluorooctane sulfonate (PFOS) was the predominant PFAS, which increased at a rate of 3.4% per year. Most long-chain perfluoroalkyl carboxylic acids increased at rates of 3.9 to 7.3% per year except for perfluorooctanoate (PFOA), which did not change significantly over time. The perfluoroalkyl acid precursors perfluorooctane sulfonamide (FOSA) and 6:2 fluorotelomer sulfonic acid were detected, of which the former (FOSA) declined at a rate of -4.4% per year, possibly reflecting its phase-out starting in 2000. An alternate time trend analysis from 2000 to 2013 produced slightly different results, with most compounds increasing at slower rates compared to the entire study period. An exception was perfluorohexane sulfonate (PFHxS), increasing at a faster rate of 3.7% measured from 2000 on, compared to the 3.0% per year measured starting from 1981. Analysis of the total fluorine content of the samples revealed large amounts of unidentified fluorine; however, its composition (organic or inorganic) remains unclear. Significant negative correlations were found between concentrations of individual PFASs (with the exception of PFOS) and liver somatic index. In addition, body length was negatively correlated with PFOA and perfluorononanoate, but positively correlated with perfluorododecanoate (PFDoDA) and FOSA. Additional studies on endocrine, immunological, and metabolic effects of PFAS in marine fish are essential to assess the environmental risk of these substances. Environ Toxicol Chem 2020;39:300-309.
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| 11. |
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| 12. |
- Schultes, Lara, et al.
(author)
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Total Fluorine Measurements in Food Packaging : How Do Current Methods Perform?
- 2019
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In: Environmental Science and Technology Letters. - : American Chemical Society (ACS). - 2328-8930. ; 6:2, s. 73-78
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Journal article (peer-reviewed)abstract
- Per- and polyfluoroalkyl substances (PFASs) represent a class of more than 4000 compounds. Their large number and structural diversity pose a considerable challenge to analytical chemists. Measurement of total fluorine in environmental samples and consumer products is therefore critical for rapidly screening for PFASs and for assessing the fraction of unexplained fluorine(i.e., fluorine mass balance). Here we compare three emerging analytical techniques for total fluorine determination: combustion ion chromatography (CIC), particle-induced gamma-ray emission spectroscopy (PIGE), and instrumental neutron activation analysis (INAA). Application of each method to a certified reference material (CRM), spiked filters, and representative food packaging samples revealed good accuracy and precision. INAA and PIGE had the advantage of being nondestructive, while CIC displayed the lowest detection limits. Inconsistencies between the methods arose due to the high aluminum content in the CRM, which precluded its analysis by INAA, and sample heterogeneity (i.e., coating on the surface of the material), which resulted in higher values from the surface measurement technique PIGE compared to the values from the bulk volume techniques INAA and CIC. Comparing CIC-based extractable organic fluorine to target PFAS measurements of food packaging samples by liquid chromatography-tandem mass spectrometry revealed large amounts of unidentified organic fluorine not captured by compound-specific analysis.
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| 13. |
- Spaan, Kyra M., et al.
(author)
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Fluorine Mass Balance and Suspect Screening in Marine Mammals from the Northern Hemisphere
- 2020
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 54:7, s. 4046-4058
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Journal article (peer-reviewed)abstract
- There is increasing evidence that the similar to 20 routinely monitored perfluoroalkyl and polyfluoroalkyl substances (PFASs) account for only a fraction of extractable organofluorine (EOF) occurring in the environment. To assess whether PFAS exposure is being underestimated in marine mammals from the Northern Hemisphere, we performed a fluorine mass balance on liver tissues from 11 different species using a combination of targeted PFAS analysis, EOF and total fluorine determination, and suspect screening. Samples were obtained from the east coast United States (US), west and east coast of Greenland, Iceland, and Sweden from 2000 to 2017. Of the 36 target PFASs, perfluorooctane sulfonate (PFOS) dominated in all but one Icelandic and three US samples, where the 7:3 fluorotelomer carboxylic acid (7:3 FTCA) was prevalent. This is the first report of 7:3 FTCA in polar bears (similar to 1000 ng/g, ww) and cetaceans (<6-190 ng/g, ww). In 18 out of 25 samples, EOF was not significantly greater than fluorine concentrations derived from sum target PFASs. For the remaining 7 samples (mostly from the US east coast), 30-75% of the EOF was unidentified. Suspect screening revealed an additional 37 PFASs (not included in the targeted analysis) bringing the total to 63 detected PFASs from 12 different classes. Overall, these results highlight the importance of a multiplatform approach for accurately characterizing PFAS exposure in marine mammals.
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| 14. |
- Zabaleta, Itsaso, et al.
(author)
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Biodegradation and Uptake of the Pesticide Sulfluramid in a Soil-Carrot Mesocosm
- 2018
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 52:5, s. 2603-2611
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Journal article (peer-reviewed)abstract
- N-ethyl perfluorooctane sulfonamide (EtFOSA) is the active ingredient of Sulfluramid, a pesticide which is used extensively in South America for control of leaf-cutting ants. Despite being a known precursor to perfluorooctanesulfonate (PFOS), the importance of EtFOSA as a source of environmental PFOS remains unclear. In the present work, uptake, leaching, and biodegradation of EtFOSA and its transformation products were assessed over 81 days in soil-carrot (Daucus carota ssp sativus) mesocosms for the first time. Experiments performed in the presence of carrot produced PFOS yields of up to 34% using a technical EtFOSA standard and up to 277% using Grao Forte, a commercial Sulfluramid bait formulation containing 0.0024% EtFOSA. Perfluorooctane sulfonamido acetate (FOSAA), perfluorooctane sulfonamide (FOSA), and perfluorooctanoic acid (PFOA) also formed over the course of the experiments, with the latter substance attributed to the presence of perfluorooctanamide impurities. The leachate contained low levels of transformation products and a high FOSA:PFOS ratio, consistent with recent observations in Brazilian surface water. In carrots, the more hydrophilic transformation products (e.g., PFOS) occurred primarily in the leaves, while the more hydrophobic products (e.g., FOSA, FOSAA, and EtFOSA) occurred in the peel and core. Remarkably, isomer-specific analysis revealed that the linear EtFOSA isomer biodegraded significantly faster than branched isomers. These data collectively show that the application of Sulfluramid baits can lead to the occurrence of PFOS in crops and in the surrounding environment, in considerably higher yields than previously thought.
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