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An integrated method is proposed for examining the compositions of fluorine-bearing gaseous mixtures, which allows for determining the concentration of HF, F2, N2, O2, CO2, CF4, and C2F6 in these mixtures. The concentration of hydrogen fluoride is determined by its sorption on sodium fluoride followed by the determination of the fluoride ion by the potentiometric method. The lower threshold of determination of hydrogen fluoride is found to be 0.09 vol.%. The concentrations of N2, O2, CO2, CF4, and C2F6 are determined by the gas chromatographic method using a thermal conductivity detector. The proposed gas-chromatography method offers a quantitative measurement of the concentration of N2, O2, CO2, CF4, and C2F6 at the lower limits of detection of 0.008, 0.012, 0.011, 0.009, and 0.019 vol.%, respectively. Based on the developed method, the compositions of a standard fluorine-nitrogen (10 vol.%) and anodic gas samples, synthesized in a laboratory electrolyzer at the National Research Tomsk Polytechnic University and in an industrial electrochemical reactor at JSC Siberian Chemical Plant (Russia), are studied.

An integrated method is proposed for examining the compositions of fluorinebearing gaseous mixtures, which allows for determining the concentration of HF, F2, N2, O2, CO2, CF4, and C2F6 in these mixtures. The concentration of hydrogen fluoride is determined by its sorption on sodium fluoride followed by the determination of the fluoride ion by the potentiometric method. The lower threshold of determination of hydrogen fluoride is found to be 0.09 vol.%. The concentrations of N2, O2, CO2, CF4, and C2F6 are determined by the gas chromatographic method using a thermal conductivity detector. The proposed gas-chromatography method offers a quantitative measurement of the concentration of N2, O2, CO2, CF4, and C2F6 at the lower limits of detection of 0.008, 0.012, 0.011, 0.009, and 0.019 vol.%, respectively. Based on the developed method, the compositions of a standard fluorine-nitrogen (10 vol.%) and anodic gas samples, synthesized in a laboratory electrolyzer at the National Research Tomsk Polytechnic University and in an industrial electrochemical reactor at JSC Siberian Chemical Plant (Russia), are studied. [ABSTRACT FROM AUTHOR]

Fluorine-containing greenhouse gases (F-GHGs) and ozone layer substances (ODS) are being monitored without a global commercial monitoring system. In this study, the existing commercial volatile organic compounds (VOCs) monitoring system is modified in hardware and optimized in methodology to provide high-precision monitoring of 33 types of ODS and F-GHGs in the atmosphere. Moreover, the system eliminates the issue of excessive costs and lengthy development cycles associated with special monitoring equipment. Pre-concentration can enhance the enrichment of low boiling point and low concentration components by increasing the injection volume, improving water removal efficiency, and improving adsorption capacity. It is significant to be noted that InertCap 624MS is a one-dimensional column, while GASPRO is a two-dimensional column. It is possible to separate 33 target compounds completely and stably by Heart-cut and TwinLine using dual-column separation and single-detector detection mode. Experimental findings indicate that this monitoring technology has an accuracy of 0.22~3.70 %. To accurately observe the changing trend of atmospheric concentration and trace the emission sources over time, a background gas with a known concentration has been used as a standard gas, and background atmospheric samples with unknown concentrations have been quantitatively tested using a single-point external standard method. [ABSTRACT FROM AUTHOR]

Aluminum (Al 3+ ) and fluorine (F - ) ions can be easily enriched in tea plants. When they excessively accumulate in tea, they can affect the health of tea lovers. Herein, a simple, highly sensitive and selective fluorescent probe (named BHMP) for Al 3+ and F - detection was developed through a one-step condensation reaction, in which benzothiazole acted as a fluorophore and acceptor and hydrazine-Schiff base as a recognition unit. The probe was characterized comprehensively using spectroscopic methods, and the structure-activity relationship was systematically researched through crystal structure and theoretical calculations. Its sensitivity was measured via the fluorescent titration experiment, and the limit of detection (LOD) towards Al 3+ was up to 1.04 × 10 -8 mol L -1 . Furthermore, we successfully utilized BHMP to visually detect the presence of Al 3+ in living cells and tea tree roots through fluorescence confocal imaging. The successful detection of Al 3+ in tea tree roots indicated that BHMP could be used as a candidate fluorescent chemosensor to dynamically monitor the variation in enriched Al 3+ under the influence of the environment during tea tree growth. Our study provides a reference for the control of Al 3+ concentration during the growth of tea plants and provides new insights into improving tea quality control.

Tea tree is a fluorine (F)-enriched plant, leading to much concern about the safety of drinking tea from tea tree (Camellia sinensis (L.) Kuntze). Tea tree is a perennial leaf-harvested crop, and tea production in China is generally categorized as spring tea, summer tea and autumn tea in its annual growth rounds. However, the seasonally dynamic changes of F content and accumulation in the leaves and its drinking safety are poorly understood. In this study, 85 tea varieties cultivated under the same conditions were investigated to analyze the seasonal variation of F content and it's relationships with F accumulation, aluminum (Al), calcium (Ca) and manganese (Mn) and hazard quotient (HQ) in young leaves (one bud and two leaves, YL) and mature leaves (canopy leaves, ML). The average F contents and accumulations were 350 mg kg -1 and 203 g ha -1 in YL, and they were 2451 mg kg -1 and 2578 g ha -1 in ML, respectively, with F mainly accumulated in ML. As the growing season progresses, the F content showed a gradual increase in YL, while a decrease in ML, inferring that F may be redistributed from mature leaves to young leaves. Additionally, the F content was quite different among tea varieties which are suitable for processing oolong tea, green tea, and black tea, with higher F accumulation in oolong tea varieties than in green and black tea varieties. Moreover, F content and accumulation could be obviously affected by the geographical origin of the tea tree varieties, with significantly higher F content in the varieties from F rich fluorite belts than other regions. Furthermore, F content and accumulation showed a significant positive correlation with the content of Al and Mn (p < 0.05). Based on a daily tea consumption of 8.7 g, the HQ was investigated to show that the proportion of tea leaves with HQ<1 made from spring, summer and autumn tender leaves of 85 varieties was 100 %, 90.6 % and 50.6 %, respectively, indicating that the tea with the best drinking safety comes from spring, followed by summer, and then autumn. This result suggests that it could be necessary to avoid planting tea trees in fluorite mining areas, choose low F tea tree varieties, and control the tenderness of fresh leaves in order to ensure the safety of tea drinking., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Fluorine (F) is a pivotal element in the formation of human dental and skeletal tissues, and the consumption of water and tea constitutes a significant source of fluoride intake. However, prolonged ingestion of water and tea with excessive fluoride content can lead to fluorosis, which poses a serious health hazard. In this manuscript, a novel turn-on fluorescent probe DCF synthesized by bis-coumarin and tert-butyldiphenylsilane (TBDPS) was introduced for detecting F - in potable water and tea infusions. By leveraging the unique chemical affinity between fluoride and silicon, F - triggers the silicon-oxygen bond cleavage in DCF, culminating in a conspicuous emission of yellow fluorescence. Validated through a succession of optical tests, this probe exhibits remarkable advantages in terms of superior selectivity, a low detection limit, a large Stokes shift, and robust interference resistance when detecting inorganic fluoride. Moreover, it can serve as portable test strips for on-site real-time identification and quantitative analysis of F - . Furthermore, the application of DCF for in-situ monitoring and imaging of F - in zebrafish and soybean root tissues proved its significant value for F - detection in both animal and plant systems. This probe potentially functions as an efficient instrument for delving into the toxic mechanisms of fluoride in physiological processes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The unique properties of per- and polyfluoroalkyl substances (PFAS) have led to their extensive use in consumer products, including ski wax. Based on the risks associated with PFAS, and to align with PFAS regulations, the international ski federation (FIS) implemented a ban on products containing "C 8 fluorocarbons/perfluorooctanoate (PFOA)" at all FIS events from the 2021/2022 season, leading manufactures to shift their formulations towards short-chain PFAS chemistries. To date, most studies characterising PFAS in ski waxes have measured a suite of individual substances using targeted analytical approaches. However, the fraction of total fluorine (TF) in the wax accounted for by these substances remains unclear. In this study, we sought to address this question by applying a multi-platform, fluorine mass balance approach to a total of 10 commercially available ski wax products. Analysis of TF by combustion ion chromatography (CIC) revealed concentrations of 1040-51700 μg F g -1 for the different fluorinated waxes. In comparison, extractable organic fluorine (EOF) determined in methanol extracts by CIC (and later confirmed by inductively-coupled plasma-mass spectrometry and 19 F- nuclear magnetic resonance spectroscopy) ranged from 92 to 3160 μg g -1 , accounting for only 3-8.8 % of total fluorine (TF). Further characterisation of extracts by cyclic ion mobility-mass spectrometry (IMS) revealed 15 individual PFAS with perfluoroalkyl carboxylic acid concentrations up to 33 μg F g -1 , and 3 products exceeding the regulatory limit for PFOA (0.025 μg g -1 ) by a factor of up to 100. The sum of all PFAS accounted for only 0.01-1.0 % of EOF, implying a high percentage of unidentified PFAS, thus, pyrolysis gas chromatography-mass spectrometry was used to provide evidence of the nature of the non-extractable fluorine present in the ski wax products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants of concern due to their long persistence in the environment, toxicity, and widespread presence in humans and wildlife. Knowledge regarding the extent of PFAS contamination in the environment is limited due to the need for analytical methods that can reliably quantify all PFAS, since traditional target methods using liquid chromatography (LC)-mass spectrometry (MS) fail to capture many. For a more comprehensive analysis, a total organic fluorine (TOF) method can be used as a screening tool. We combined TOF analysis with target LC-MS/MS analysis to create a statewide PFAS hotspot map for surface waters throughout South Carolina. Thirty-eight of 40 locations sampled contained detectable concentrations of organic fluorine (above 100 ng/L). Of the 33 target PFAS analyzed using LC-MS/MS, the most prevalent were perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), and perfluorohexanesulfonate (PFHxS). On average, LC-MS/MS only accounted for 2 % of the TOF measured. Locations with high TOF did not necessarily correlate to high total quantified PFAS concentrations and vice-versa, demonstrating the limitations of target PFAS analysis and indicating that LC-MS may miss highly contaminated sites. Results suggest that future surveys should utilize TOF to more comprehensively capture PFAS in water bodies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The cosmic origin of fluorine is still under debate. Asymptotic giant branch (AGB) stars are among the few suggested candidates to efficiently synthesis F in our Galaxy, however their relative contribution is not clear. In this paper, we briefly review the theoretical studies from stellar yield models of the F synthesis and chemical equilibrium models of the F-containing molecules in the outflow around AGB stars. Previous detections of the F-bearing species towards AGB and post-AGB stars are also highlighted. We suggest that high-resolution ALMA observations of the AlF, one of the two main carriers of F in the outflow of AGB stars, can provide a reliable tracer of the F-budget in AGB stars. This will be helpful to quantify the role of AGB stars in the Galactic F budget. [ABSTRACT FROM AUTHOR]

Cryogenic etching of silicon is a route to high aspect ratio silicon features with high mask selectivity and smooth sidewalls. These benefits have been realized even down to 10 nm half-pitch features. In this work, we develop a semi-empirical simulation model to understand mechanisms responsible for nanoscale profile evolution during plasma etching of silicon in SF6/O2 chemistry at cryogenic temperatures. The model parameters are first calibrated to the etching equipment using features from 500 nm to 2 µm. Using the calibrated model, we show the experimental finding that smaller features need more oxygen to achieve vertical anisotropic profiles. This is a consequence of two related effects: (1) the SiOxFy passivation layer sputtering yield is strongly dependent on the oxygen content at the feature sidewalls and (2) Knudsen transport within small features or higher aspect ratios depletes oxygen faster than fluorine due to the higher sticking coefficient of oxygen. The simulation was applied to 25 nm half-pitch features with excellent results. [ABSTRACT FROM AUTHOR]

Hamburger wrapping paper, coated with water-based barrier coatings, used in the food packaging industry was studied by using the total organic fluorine (TOF) method based on combustion ion chromatography and fluorine-19 solid-state nuclear magnetic resonance ( 19 F ss-NMR) spectroscopy. Although the TOF method is a fast and affordable method used to screen for per- and polyfluoroalkyl substances (PFAS), the amount of fluorine it measures is heavily dependent on the extraction step and, therefore could lead to inaccurate results. Fluorine-19 ss-NMR spectroscopy can differentiate between organic and inorganic fluorinated sources, eliminating the need for sample clean up. To illustrate this, the 19 F ss-NMR spectra of clean coated paper samples that contained naturally occurring F - ions from the talc raw material and spiked samples containing perfluorooctanoic acid were compared. A range of experimental conditions was explored to improve sensitivity for low PFAS concentrations (in the order of 10-20 mg/kg). Despite the disadvantages of ss-NMR spectroscopy, such as the low limit of detection and resolution, the results demonstrate it can be a viable tool to directly detect PFAS moieties in consumer and food packaging. Therefore, 19 F solid-state NMR spectroscopy challenges and complements current methods, which only provide indirect evidence of the presence of PFAS.

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.

Wild boars have been reported as bioindicators for per- and polyfluoroalkyl substances (PFAS) in a variety of studies. However, data about PFAS levels in wild boars from sites with limited industrial and general human activity is scarce. In this study, wild boar (Sus scrofa) organs from the Bohemian Forest National Park (Czech Republic) were used as bioindicators for PFAS pollution. In this work, 29 livers and 24 kidneys from 30 wild boars (0.5-5 years) were investigated using a fluorine mass balance approach. For this, the samples were measured using high performance liquid chromatography with electrospray ionisation tandem mass spectrometry (HPLC-ESI-MS/MS), targeting 30 PFAS, including legacy and replacement PFAS, direct total oxidisable precursor assay (dTOPA) and combustion ion chromatography (CIC). Perfluorocarboxylic acids (PFCAs) from C 7 to C 14 and perfluorooctanesulfonic acid (PFOS) were detected in >50 % of samples. In the livers, PFCAs dominated the profile with median concentrations of 230 μg/kg for perfluorononanoic acid (PFNA) and 75 μg/kg perfluorooctanoic acid (PFOA). PFOA and PFNA concentrations in the livers were one order of magnitude higher than in livers from wild boars caught in rural NE Germany considered as background concentration. PFOS in liver contributed only 30 % to the Σc(PFAS Target ) with a median concentration of 170 μg/kg. Kidneys and livers contain an average of 2460 μg F/kg and 6800 μg F/kg extractable organic fluorine (EOF) respectively. Σc(PFAS Target ) add up to a maximum of 10 % of the extractable organic fluorine. After oxidisation of the samples, PFOA, PFNA and Σc(PFAS dTOPA ) increased in livers, but could not explain the EOF. The elevated concentration of PFOA and PFNA may indicate differences in biomagnification for different habitats or an unidentified PFAS source in proximity to the national park., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

The pH of Mount Ijen crater water is 0-2, resulting in water that is acidic and sulfurous. A fault near the Mount Ijen Crater causes seepage so that acidic water flows into the Banyupait River. Chemical elements and heavy metals originating from the river pollute groundwater and plants. As a result, people around the river consume heavy metals. This research aims to determine the quality of river water and groundwater, as well as determine community factors that are susceptible to dental fluorosis. The methodology used is field mapping and laboratory analysis. For water samples, the Atomic Absorption Spectrophotometer (AAS) method is used. The pH of river water at the research location exceeds the quality standard, namely pH 4-5.5. Meanwhile, groundwater fluorine and sulfate elements exceed quality standards, namely fluorine of 0.6171 mg/L and 0.6870 mg/L, and sulfate ranging from 325-683 mg/L. These two elements cause symptoms of dental fluorosis. Meanwhile, the community factors most susceptible to dental fluorosis are people in the adult age category, and the last level of education is elementary school. This is because the Banyupait River water and groundwater are exposed to fluorine and sulfate water originating from seepage from the Mount Ijen Crater., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).)

Coal fire sponges (CFSs) are a type of sponge-like contaminated soil bulge common in coal fire areas. However, the impacts of CFSs on the local environment are not yet understood. Thus, this study investigated soil samples from CFSs in the Wuda coalfield, Inner Mongolia, China, focusing on the acidity, sulfate, and fluorine content. The results showed that the CFSs were highly acidic, with an average pH of 0.76, and contained high levels of SO 4 2- (257.29 × 10 3  μg/g), total fluorine (TF, 2011.6 μg/g), and water-soluble fluorine (WF, 118.94 μg/g), significantly exceeding those in the regional background soil and indicating that CFSs are a point source of heavy pollution. Soils in the 8000 m 2 reclamation zone showed elevated acidity and high SO 4 2- (129.6 × 10 3  μg/g), TF (1237.8 μg/g), and WF (43.05 μg/g) levels, which was likely the result of the weathering and dissemination of CFS. The CFS samples were rich in hydrogen fluoride, releasing 202.05 ppb of it when heated to 40 °C. Correlation analysis indicated that the acid sulfate soils in CFSs are likely caused by HSO 4 - /SO 4 2- . Time-of-flight secondary ion mass spectrometry detected four characteristic ions (F - , H 3 O + , H 2 SO 4 + , and HSO 4 - ) in all micro-domains of each sample, indicating that ionic fluorine compounds and sulfuric acid hydrate were found in the CFS samples. Sulfate minerals detected in CFSs included CaSO 4 , Fe 2 (SO 4 ) 3 , CdSO 4 , NH 4 HSO 4 , and Na 2 SO 4 . Thus, the results identified CFSs as a transmission channel for contamination, with erosional surface soils as the carrier, for the first time. CFSs pose a serious threat of contamination, albeit over limited areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Fluoride pollution in water has become a global challenge. This challenge especially affects China as a country experiencing serious fluoride pollution. While the have been past studies on the spatial distribution of fluoride, there has been less attention on different forms of fluoride. This study collected 176 samples (60, 40, and 76 ice, water, and sediment samples, respectively) from Lake Ulansuhai during the freezing period. The occurrence and spatial distribution characteristics of fluoride in lake ice-water-sediment were explored using Kriging interpolation, Piper three-line diagram, and Gibbs diagram analysis methods. The migration and transformation of fluoride during the freezing period were revealed and the factors influencing fluoride concentration in the water body were discussed considering the hydrochemical characteristics of lake surface water. The results showed that the average fluoride concentrations in the upper ice, middle ice and lower ice were 0.18, 0.09, and 0.12 mg/L, respectively, decreasing from north to south in the lake. The average concentrations of fluoride in surface water and bottom water were 0.63 and 0.83 mg/L, respectively. The concentrations of fluoride in ice and water were within the World Health Organisation drinking water threshold of 1.50 mg/L and the Class III Chinese surface water standard (GB3838-2002). The average sediment total fluorine was 1344.38 ± 200 mg/kg, significantly exceeding the global average (321 mg/kg) and decreasing with depth. The contents of water soluble, exchangeable, Fe/Mn bound, organic bound, and residual fluorides were 40.22-47.18, 13.24-43.23, 49.52-160.48, and 71.59-173.03 mg/kg, respectively. There was a significant positive correlation between fluoride concentration in ice and that in water. The change in fluoride concentration in water was mainly due to specific climatic and geographical conditions, pH, hydrochemical characteristics and ice sealing. This study is of great significance for the management of high-fluorine lakes in arid and semi-arid areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The distribution of Non-Bridging Oxygen Hole Centers (NBOHCs) in fluorine doped optical fibers was investigated by confocal microluminescence spectroscopy, monitoring their characteristic 1.9 eV luminescence band. The results show that these defects are generated by the fiber drawing and their concentration further increases after γ irradiation. The NBOHC concentration profile along the fiber provides evidence for an exponential decay with the fluorine content. This finding agrees with the role of fluorine in the fiber resistance and is discussed, from the microscopic point of view, by looking at the conversion mechanisms from strained bonds acting as precursors. [ABSTRACT FROM AUTHOR]

The antifreeze glycoproteins [AFGPs] are large molecules with molecule weights of 2.6-33 kDa, which exhibit prominent antifreeze property and enable their organisms to survive in below the melting point of water. While AFGPs have gained much attention in recent years, their availability is highly limited to the isolation from natural resources. Although the total syntheses of AFGPs have been reported, the synthetic methods have been limited due to their inherent gigantic molecular structures. Thus the development of efficient synthetic alternatives of AFGPs with middle molecules is highly desirable. We herein design the novel candidates of antifreeze molecules consisting of galactose-conjugated fluorinated and non-fluorinated proline oligomers. They were designed based on the PP II helix with hydrophilic and lipophilic parts, which could induce the potential antifreeze property. The target galactose-proline oligomers were synthesized, and their physical properties were evaluated. Despite our expectation, the non-fluorinated galactose-proline oligomers showed weak antifreeze activity in contrast to the fluorinated analogues. The difference in antifreeze activity would be attributed to the fluorine gauche effect, which induces a different conformation in fluorinated prolines from that of natural proline. These results suggest that the 3D structures of the galactose-conjugated fluorinated and non-fluorinated proline oligomers are critical for their antifreeze properties. [ABSTRACT FROM AUTHOR]

Total fluorine was determined in 45 consumer product samples from the Swedish market which were either suspected or known to contain fluorinated polymers. Product categories included cookware (70-550 000 ppm F), textiles (10-1600 ppm F), electronics (20-2100 ppm F), and personal care products (10-630 000 ppm F). To confirm that the fluorine was organic in nature, and deduce structure, a qualitative pyrolysis-gas chromatography-mass spectrometry (pyr-GC/MS) method was validated using a suite of reference materials. When applied to samples with unknown PFAS content, the method was successful at identifying polytetrafluoroethylene (PTFE) in cookware, dental products, and electronics at concentrations as low as 0.1-0.2 wt%. It was also possible to distinguish between 3 different side-chain fluorinated polymers in textiles. Several products appeared to contain high levels of inorganic fluorine. This is one of the few studies to quantify fluorine in a wide range of consumer plastics and provides important data on the concentration of fluorine in materials which may be intended for recycling, along with insights into the application of pyr-GC/MS for structural elucidation of fluorinated polymers in consumer products.

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.

The study was performed in natural forests preserved within the Boreal zone city, Irkutsk, Russia. Test sites were selected in the forests in different districts of the city, where samples of Scots pine (Pinus sylvestris L.) and Siberian larch (Larix sibirica Ledeb.) needles were taken to study the adsorption on their surface of aerosol particles of different sizes, in microns: PM 0.3 , PM 0.5 , PM 1 , PM 2.5 , PM 5 , PM 10 . Scanning electron microscopy was used to obtain high-resolution photographs (magnification 800- × 2000, × 16,000) and aerosol particles (particulate matter-PM) were shown to be intensively adsorbed by the surface of needles, with both size and shape of the particles characterized by a wide variety. Pine needles can be covered with particles of solid aerosol by 50-75%, stomata are often completely blocked. Larch needles often show areas, which are completely covered with aerosol particles, there are often found stomata deformed by the penetration of PMx. X-ray spectral microanalysis showed differences in the chemical composition of adsorbed PMx, the particles can be metallic if metals predominate in their composition, carbonaceous-in case of carbon predominance-or polyelemental if the composition is complex and includes significant quantities of other elements besides metals and carbon (calcium, magnesium, potassium, sodium, sulfur, chlorine, fluorine). Since the particles contain a large proportion of technogenic pollutants, accumulation by the needles of some widespread pollutants was investigated. A direct correlation of a highly significant level between the concentration of PMx in the air and the accumulation of many heavy metals in pine and larch needles, as well as sulfur, fluorine, and chlorine, has been revealed, which indicates a high cleaning capacity of urban forests. At the same time, the negative impact of PMx particles on the vital status of trees is great, which shows in intense disturbance of the parameters of photosynthesis and transpiration, leading to a significant decrease in the growth characteristics of trees and reduction in the photosynthetic volume of the crowns. We consider that the results obtained are instrumental in developing an approach to improvement of urban forests status and creating a comfortable urban environment for the population., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Abstract Fluorine and aluminum co-doped ZnO (FAZO) films were deposited on glass substrates by RF magnetron sputtering. The effects of the substrate temperature (T sub) on the structural, morphological, electrical, and optical properties of the films were investigated by X-ray diffraction analysis, atomic force microscopy, photoluminescence spectroscopy, Hall effect measurement, and ultraviolet–visible–near infrared spectrophotometry. All the thin films showed typical wurtzite structure with the c axis preferentially oriented perpendicular to the substrate. With increasing T sub , the grain size shows a parabolic-like enhancement; the film surface became relatively smooth and dense, and the crystallinity was also improved. At T sub = 320 °C, the films showed the best electrical properties, with a resistivity of 3.53 × 10−4 Ω cm, Hall mobility of 39.33 cm2/V s, and carrier concentration of 4.50 × 1020 cm−3. An optical transmittance of more than 80% in a wide wavelength range from 400 to 1200 nm was also achieved. Perovskite solar cells employing the FAZO film had a higher power conversion efficiency than reference cells using F-doped SnO 2 and Sn-doped In 2 O 3 , demonstrating its suitability for application in high-efficiency solar cells. Graphical abstract fx1 Highlights • High mobility, low resistivity and wide spectral transmittance FAZO films were deposited on glass substrates. • Perovskite solar cells employing FAZO film shows higher performance than reference cells using FTO and ITO films. • Good electrical and optical properties as well as the application for perovskite solar cells show that FAZO films have wide application prospects in high-efficiency solar cells. [ABSTRACT FROM AUTHOR]

Abstract While F is an essential constituent of some rock-forming minerals such as fluorite and apatite, its major occurrence in the lithosphere is within hydroxysilicate minerals where F− occupies OH− lattice sites. The majority of the F occurring in the secondary environment derives from natural weathering processes with some soils derived from F-rich parent rocks containing over 1weight (wt) % F. Other natural sources of F are vulcanicity, wind-blown dust and a minor marine-derived component, with biomass burning, being in part natural, also a source. Several anthropogenic sources of environmental F have also been identified. Of the anthropogenic sources, the application of phosphate fertiliser, which probably adds over 2.3 Mt a−1 F to soils globally, represents the largest. While much of this is strongly retained in soils, in acidic some may be transferred to groundwater. In some abandoned mine sites in the UK where fluorite was associated with the mineralisation, soil F contents of up to 8 wt % have been recorded with plants growing on the sites containing up to 1wt % F. The rapid growth of urban areas in India, Pakistan and Bangladesh has resulted in an upsurge of brickmaking in Asia, with these 3 countries plus China accounting for over 75% of global brick production. As a result there is a large number of unregulated brick kilns which emit HF into the surrounding environment. Based on an annual global brick production of 1500 billion and the F contents of brick clays, it is estimated that about 1.8 Mt a−1 F are released to the environment from brick manufacture. This suggests that brickmaking is the largest source of atmospheric F emissions dwarfing that of coal combustion, 0.2–0.3 Mt a−1, phosphate fertiliser production, 0.07–0.10 Mt a−1, aluminium smelting, 0.041 Mt a−1, and even vulcanicity, 0.3–0.7 Mt a−1. However, it is apparent that atmospheric F emissions are not transported globally and as such their effects are manifested only in the local environment. Emissions from industry sited close to urban centres can impact these environments together with domestic coal combustion and the release of F from high octane fuels in motor vehicles. A more recent source of F in the environment stems from the large number of fluorocarbon compounds in everyday use. Degradation of some of these fluorocarbon compounds together with pyrolysis of fluoropolymers and burning of household refuse has resulted in the deposition of organofluorine compounds such trifluoroacetic acid in the environment. Highlights • The majority of the F occurring in the secondary environment derives from natural weathering processes. • The application of phosphate fertiliser is the largest anthropogenic source of F in the environment, probably adding over 2.3 Mt a−1 F to soils globally. • Global brick production is estimated to release about 1.8 Mt a−1 F, making it the largest source of F emissions to the atmosphere. • Other anthropogenic sources of F emissions to the atmosphere are coal combustion, 0.2–0.3 Mt a−1, phosphate fertiliser production, 0.07–0.10 Mt a−1 and aluminium smelting, 0.041 Mt a−1. • Vulcanicity has been estimated to release 0.3–0.7 Mt a−1to the atmosphere. [ABSTRACT FROM AUTHOR]

In this paper, the mesoporous silica (denoted as Ms) was modified by cerium and the optimum preparation conditions were investigated for cerium loaded mesoporous silica materials (denoted as Ms-Ce). The Ms-Ce materials for the fluoride removal performance were characterized by using SEM, XRD, FT-IR and TG-DTA. The Ms-Ce had good defluorination performance due to its large surface area and good-dispersive effect. The results show that cerium is successfully loaded onto the surface of the Ms and the structure of Ms did not change during the loading process. The defluorination loading by Ms-Ce can reach 75.54% under the optimum conditions (nNaHCO3/nCe = 3.0, nCe/nSi = 0.08 and 90°C drying temperature). The adsorption performance and capacities of Ms-Ce were investigated through adsorption kinetics and adsorption isotherm tests. The maximum fluorine removal efficiency on the loaded materials were that the adsorbent dosage, pH value and adsorption time. They were showed as 1.6 g/L, 3.0 and 240 min, respectively. Dynamics research results showed that the fluoride removal process conformed to pseudo-second order kinetic model. Isothermal adsorption results showed that the fluorine ion adsorption process of Ms-Ce was accord with the Langmuir isotherm adsorption model. The maximum adsorption capacity was 17.96 mg/g. The mainly reaction showed that the active component of cerium carbonate has completed ion exchange with fluoride ion to generate CeCO3F. [ABSTRACT FROM AUTHOR]

Abstract: Au@Pd nanoparticles (NPs) with different atomic ratios (4:1, 1:1, 1:4) are synthesized via a simple one-step ultraviolet irradiation method, which are self-assembled on the surface of multi-walled carbon nanotubes modified by -F groups (HF−MWCNTs). The morphology, structure and composition of catalysts are characterized by ultraviolet visible spectra (Uv-Vis), transmission electron microscopy (TEM), high-angle annular dark-filed scanning TEM (HAADF-STEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results display Au@Pd (1:4) NPs have a clear core-shell structure. All of Au@Pd NPs can be uniformly dispersed on the HF−MWCNTs. Methanol oxidation performance of the catalysts is measured by cyclic voltammetry (CV) and chronoamperometry (i−t). Electrochemical tests indicate that Au@Pd/MWCNTs (1:1) catalyst exhibits the excellent electrocatalytic activity and best durability toward methanol oxidation in alkaline media, which is 4.4 times higher than that of the commercial Pd/C. This enhanced electro-catalytic performance could be attributed to uniform dispersion, synergetic effect of core-shell structure, strong metal-support interaction (SMSI effect) between -F functional groups and NPs. The -F groups can interact with Au and Pd atoms to form fluorine complexes, which change the electronic structure of Au and Pd atoms so as to enhance the activity and stability of the Au@Pd/MWCNTs (1:1) catalyst.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Abstract The solvent vapor annealing (SVA) technique is one of the useful post processing techniques of a thin film, which is an alternative technique of the thermal annealing one. SVA has a great advantage that the molecular rearrangement in the film is made moderately by employing an appropriate solvent without the sample heating. The moderate processing is expected to yield a benefit that the molecular coalescence would be suppressed, which would readily keep the continuous surface topography of the film during the annealing, and another benefit that a metastable structure would be obtained. To make the best use of the SVA-specific characteristics, in the present study, a material having a metastable structure is chosen. The sample is zinc tetraphenylporphyrin (ZnTPP) that yields a metastable triclinic crystal structure, which can easily be converted to a monoclinic crystal structure by thermal annealing. A triclinic-structure film of ZnTPP by the combination of a wet process and the thermal annealing has thus never been reported. By choosing a fluorine-containing solvent, which has a low affinity to ZnTPP, a triclinic-structure film has first been obtained by a wet process while the surface continuity is protected. Highlights • A metastable triclinic crystal of ZnTPP is first obtained by a wet process. • A weak affinity solvent to ZnTPP makes the solvent vapor annealing successful. • The continuous surface topography of the ZnTPP film is readily remained. • The characterization is performed by using the 2D-GIXD and IR pMAIRS techniques. [ABSTRACT FROM AUTHOR]

Abstract The electrical characteristics and XPS analysis for the amorphous tungsten and zinc doped indium oxide thin film transistor, which was performed with single or double different fluorine based remote plasma treatment, were investigated in this study. A high mobility TFT device with the tungsten doped channel was fabricated in the previous study, but there was an inevitable negative shift for the threshold voltage, which will be a limit for the application of systemic circuit design. Therefore, a double fluorine based remote plasma treatment process is proposed for the high electronegativity of fluorine element and its similar radius as oxygen, which can be used to terminate the donor-like oxygen vacancy. It may induce a positive shift of threshold voltage, while carrier concentration and field effect mobility might be maintained. As a result, the sample with CF 4 /N 2 + O 2 plasma treatment exhibits a higher on/off current ratio of ~4.73 × 106, a lower sub-threshold swing value of 0.070 V/decade, and a lower interfacial trap density value of 5.21 × 1011 eV−1 cm−2 than other samples, while there is even a desirable positive shift of threshold voltage and acceptable field effect mobility of 31.2 cm2/Vs. This research proposes an effective approach to improve the reliability characteristic and adjust the inevitable negative shift of threshold voltage without sacrificing the carrier mobility of device. Highlights • The devices with tungsten doped channel and a fluorine based double remote plasma treatment process are discussed. • The devices with CF 4 /N 2 +O 2 plasma treatment exhibit an enhancement on the electrical characteristics and reliability. • The mechanism of fluorination and the interaction between different plasma have been investigated by XPS analysis. [ABSTRACT FROM AUTHOR]

Abstract: A novel flake-ball-like magnetic Fe 3 O 4 /γ-MnO 2 meso-porous nano-composite was synthesized and characterized for defluoridation. Adsorption process, characters, and effects of solution chemistry on the adsorption of flourinion in Fe 3 O 4 /γ-MnO 2 were evaluated. The results show that the adsorption of fluorinion in the Fe 3 O 4 /γ-MnO 2 nano-composite is fitted with the Pseudo-first model and the Langmuir model, indicating that the adsorption process of fluorinion in the Fe 3 O 4 /γ-MnO 2 nano-composite was a physical process and not only controlled by the film diffusion but also controlled by the intra-particle diffusion and surface adsorption. It shows that the adsorption of fluorinion sharply decrease with the increase of pH due to the negative changed surface of Fe 3 O 4 /γ-MnO 2 in water and the competition of OH − for the active points. The competition from decreases the adsorption of fluoride in the order of Cl −  < NO 3 −  < SO 4 2− , which relied on the ratio of charge towards radius (z/r) of the anions, and the negatively charged humic acid competed with fluorinion for the adsorption sites. Based on the adsorption results and the XPS analysis, the O Mn bond in the raw adsorbent supported the active site (O Mn OH) for fluoride adsorption by forming an O Mn F bond on the surface of Fe3O4/γ-MnO2. [ABSTRACT FROM AUTHOR]

Based on an easy and scalable method for the synthesis of quinoline derivatives substituted by fluorinated groups at both the C‐2 and C‐4 positions developed in our laboratory, we have devised an approach to the synthesis of a new series of unprecedented 2,4‐bis(fluoroalkyl)quinoline‐3‐carboxylates in just two steps. After standard saponification, the latter gave the corresponding 2,4‐bis(fluoroalkyl)quinoline‐3‐carboxylic acids, which served as pivotal intermediates for post‐functionalization reactions. Indeed, the carboxylic group could then be derivatized according to known procedures to introduce chemical diversity at the C‐3 position of these unprecedented structures. The resulting highly functionalized quinolines can serve as a platform for the development of biologically active molecules with strong potential for agrochemical research. [ABSTRACT FROM AUTHOR]

Detection of fluorine with commercial ICPMS is impossible due to the high ionisation potential (IP) of fluorine. A novel approach through the formation of fluorine-containing polyatomic ions [M–F]+ in the plasma allows the successful detection of F at sub ppm levels by ICPMS/MS. Two theories behind [M–F]+ formation have been proposed, yet there is no clear understanding about the mechanism. Here, different metal solutions were tested for the characterisation of plasma processes in the formation of [M–F]+. Three characteristics: high [M–F]+ bond dissociation energy (BDE), low [M–O]+ BDE and low IP were found to be essential to get the highest sensitivity for [M–F]+. It was found that for elements with a higher [M–F]+ BDE than [M–O]+ BDE, the sensitivity decreases linearly with the second IP of the element, meaning that the major process in the plasma is the harvesting of F− by M2+ to form [M–F]+. Barium exhibited the highest sensitivity for [M–F]+. However, the robustness of this approach was questioned due to matrix effects, hence an argument for re-developing negative ion ICPMS/MS was discussed in which detection limits in the sub-ppb range could be reached. [ABSTRACT FROM AUTHOR]

Wuda coalfield in Inner Mongolia is one of China's typical old coal bases and has a coal fire history of over 50 years. Many studies have been carried out on fluorine pollution caused by high-temperature processing industries such as those related to the production of steel, aluminum, glass, brick, and tile. However, few studies have focused on fluorine pollution caused by coal-fired industrial parks or coal fires. For the present study, 224 dust samples were collected from Wuda district in Inner Mongolia and its surrounding zones, covering a total area of ~270 km 2 . Subsequently, fluorine concentrations in the samples were analyzed using the combustion–hydrolysis/fluoride-ion selective electrode method. Results showed that the average fluorine concentration of dust is 848 μg·g −1 (430–1504 μg·g −1 ) in Wuda coalfield and 1016 μg·g −1 (237–2830 μg·g −1 ) in industrial parks, which are more than four times the background value. The average fluorine concentration in the adjoining downwind urban area of Wuda is 488 μg·g −1 , which is twice the background value. The results indicate that long-term fluorine release from the coal fire and industrial parks leads to significantly elevated fluorine concentration levels in the dust around the study area. The scenario of urban areas in close proximity to coal seam fires and industrial parks is not particular to Wuda; it is relatively common in northern China and elsewhere. Thus, the influence of coal seam fire and industrial parks on other cities merits further investigation. [ABSTRACT FROM AUTHOR]

The authors developed a tool using a multiscale approach to simulate the silicon etching using Bosch process. Their study is focused on the analysis of the effect of the oxygen addition to C4F8 plasma during the deposition pulse. This is the complementary study that the authors have recently published which was dedicated to the Bosch process under pure SF6 plasma used in etching pulse and pure C4F8 plasma used in polymer deposition pulse. Parametric study about the effect of the oxygen percentage on the reactive species flux evolution and their impact on the deposition kinetic during the deposition pulse has been performed. The simulation results reveal that for a low %O2 in a C4F8/O2 plasma mixture, the atomic fluorine density increases because of the volume reactions, especially recombinations between CFx and O which favor the production of fluorine. This leads to the decrease of CFx to F flux ratio. Ion energy distribution functions (IEDF) plotting reveals the impact of both %O2 and mass of the positive ions on the IEDF shape. Finally, both the experimental and simulation results show that in their pressure range, the addition of O2 to C4F8 plasma has a weak impact on the silicon etch profile and the etching rate, except for a high %O2 which the etch anisotropy begins to be degraded. [ABSTRACT FROM AUTHOR]

Nano crystalline undoped (1Z) Zinc Oxide (ZnO) and 5, 10 and 15 Wt. % (1ZN, 2ZN and 3ZN) of Nickel doped ZnO based sensors were fabricated using the hydrothermal approach on Fluorine doped Tin Oxide (FTO) glass substrates. X-ray diffraction (XRD) analysis proved the hexagonal Wurtzite structure of ZnO. Parametric variations in terms of dislocation density, bond length, lattice parameters and micro strain with respect to dopant concentration were analysed. The prominent variations in the crystallite size, optical band gap and Photoluminescence peak ratio of devices fabricated was observed. The Field Emission Scanning Electron Microscope (FESEM) images showed a change in diameter and density of the nanorods. The effect of the operating temperature, concentration of ethanol and the different doping levels of sensitivity, response and recovery time were investigated. It was inferred that 376% of sensitivity with a very quick response and recovery time of <5 s and 10 s respectively at 150 °C of 3ZN sensor has better performance compared to other three sensors. Also 3ZN sensor showed improved sensitivity of 114%, even at room temperature with response and recovery time of 35 s and 45 s respectively. [ABSTRACT FROM AUTHOR]

Fluorite, a chief source of fluorine in the nature, usually coexists with calcite mineral in ore deposits. Worldwide, flotation techniques with a selective collector and/or a selective depressant are commonly preferred for the separation of fluorite from calcite. In the present study, an attempt was made to use benzhydroxamic acid (BHA) as a collector for the selective separation of fluorite from calcite without using any depressant. Results obtained from the flotation experiments for single mineral and mixed binary minerals revealed that the BHA has a good selective collecting ability for the fluorite when 50 mg/L of BHA was used at pH of 9. The results from the zeta potential and X-ray photoelectron spectroscopy (XPS) indicated that the BHA easily chemisorbs onto the fluorite as compared to calcite. Crystal chemistry calculations showed the larger Ca density and the higher Ca activity on fluorite surface mainly account for the selective adsorption of BHA on fluorite, leading to the selective separation of fluorite from calcite. Moreover, a stronger hydrogen bonding with BHA and the weaker electrostatic repulsion with BHA − also contribute to the stronger interaction of BHA species with fluorite surface. [ABSTRACT FROM AUTHOR]

This work reported a simple route for preparing CeO2/CeF3 composite powders. Cerium nitrate hexahydrate, oxalic acid dihydrate and ammonium fluoride were milled and subsequently calcined to obtain the composite powders. X-ray diffractometer, field emission scanning electron microscope, transmission electron microscopy, zeta potential tester, and polishing test were utilised to characterise those products and study the effect of doped fluorine amount on their physicochemical characteristics and chemical mechanical polishing properties. The results show that incorporation of 7 wt% fluorine into the starting materials can change the particle morphology from large sheet for pure CeO2 into uniform spherical particles with size of 30-50 nm. The composite powder with 7 wt% fluorine exhibits great suspension stability and relatively high material removal rate. Meanwhile, this slurry facilitates obtaining smoother surface after polishing, which may be related to the changes of particle morphology and decrease in overall hardness of abrasives. [ABSTRACT FROM AUTHOR]

Purpose: Our previous studies with F-18-labeled anti-HER2 single-domain antibodies (sdAbs) utilized 5F7, which binds to the same epitope on HER2 as trastuzumab, complicating its use for positron emission tomography (PET) imaging of patients undergoing trastuzumab therapy. On the other hand, sdAb 2Rs15d binds to a different epitope on HER2 and thus might be a preferable vector for imaging in these patients. The aim of this study was to evaluate the tumor targeting of F-18 -labeled 2Rs15d in HER2-expressing breast carcinoma cells and xenografts.Procedures: sdAb 2Rs15d was labeled with the residualizing labels N-succinimidyl 3-((4-(4-[18F]fluorobutyl)-1H-1,2,3-triazol-1-yl)methyl)-5-(guanidinomethyl)benzoate ([18F]RL-I) and N-succinimidyl 4-guanidinomethyl-3-[125I]iodobenzoate ([125I]SGMIB), and the purity and HER2-specific binding affinity and immunoreactivity were assessed after labeling. The biodistribution of I-125- and F-18-labeled 2Rs15d was determined in SCID mice bearing subcutaneous BT474M1 xenografts. MicroPET/x-ray computed tomograph (CT) imaging of [18F]RL-I-2Rs15d was performed in this model and compared to that of nonspecific sdAb [18F]RL-I-R3B23. MicroPET/CT imaging was also done in an intracranial HER2-positive breast cancer brain metastasis model after administration of 2Rs15d-, 5F7-, and R3B23-[18F]RL-I conjugates.Results: [18F]RL-I was conjugated to 2Rs15d in 40.8 ± 9.1 % yield and with a radiochemical purity of 97-100 %. Its immunoreactive fraction (IRF) and affinity for HER2-specific binding were 79.2 ± 5.4 % and 7.1 ± 0.4 nM, respectively. [125I]SGMIB was conjugated to 2Rs15d in 58.4 ± 8.2 % yield and with a radiochemical purity of 95-99 %; its IRF and affinity for HER2-specific binding were 79.0 ± 12.9 % and 4.5 ± 0.8 nM, respectively. Internalized radioactivity in BT474M1 cells in vitro for [18F]RL-I-2Rs15d was 43.7 ± 3.6, 36.5 ± 2.6, and 21.7 ± 1.2 % of initially bound radioactivity at 1, 2, and 4 h, respectively, and was similar to that seen for [125I]SGMIB-2Rs15d. Uptake of [18F]RL-I-2Rs15d in subcutaneous xenografts was 16-20 %ID/g over 1-3 h. Subcutaneous tumor could be clearly delineated by microPET/CT imaging with [18F]RL-I-2Rs15d but not with [18F]RL-I-R3B23. Intracranial breast cancer brain metastases could be visualized after intravenous administration of both [18F]RL-I-2Rs15d and [18F]RL-I-5F7.Conclusions: Although radiolabeled 2Rs15d conjugates exhibited lower tumor cell retention both in vitro and in vivo than that observed previously for 5F7, given that it binds to a different epitope on HER2 from those targeted by the clinically utilized HER2-targeted therapeutic antibodies trastuzumab and pertuzumab, F-18-labeled 2Rs15d has potential for assessing HER2 status by PET imaging after trastuzumab and/or pertuzumab therapy. [ABSTRACT FROM AUTHOR]

This work presents a method for simultaneous proton induced gamma-ray emission analysis of fluorine, lithium, and sodium in 'as received' geological reference materials. 1.7, 2.4 and 3.0 MeV proton energies were chosen for this study. The choice of the most appropriate incident energy was made after the study of the variation of the signal/background ratio, the limit of detection, the duration of the analysis and the number of counts/µC for each element. Quantitative calculation was achieved using an external standard and the so-called E analytical approach. For this purpose, the thick target yield of the gamma rays at 110, 197, 440 and 478 keV were given between 1.1 and 3.0 MeV proton energies. [ABSTRACT FROM AUTHOR]

A novel fluorescent probe 1 has been synthesized by a microwave reaction, and its ion-binding and fluorescence-sensing properties have been investigated under different solvent conditions. The analysis results indicated that probe 1 can act as a multiple analysis probe by simply tuning the solvent. Probe 1 exhibited high selectively toward Hg 2+ through fluorescence quenching in H 2 O/DMF. In H 2 O/1,4-dioxane solution, probe 1 selectively recognized and discriminated between Ag + and Hg 2+ displaying ratiometric behaviour. Moreover, probe 1 readily recognized the anion F − via the ratiometric fluorescent mode in CH 3 CN. Furthermore, distinct colour changes were observed under UV light, which can be seen by the naked eye and thus used for distinguishing Hg 2+ , Ag + and F − from the other ions screened herein using probe 1 . Interestingly, almost pure white light emission was evident by simply tuning the F − anion-concentration, which makes this system a potential candidate for smart and tunable luminescent materials. [ABSTRACT FROM AUTHOR]

The Late Precambrian–Early Palaeozoic crystalline basement of the Ventania System is mainly composed of Neoproterozoic S-type granites, Early Cambrian alkaline granites, and Middle Cambrian peralkaline rhyolites. The Neoproterozoic granites ( ca. 607–581 Ma) crop out in the Cerro Pan de Azúcar-Cerro del Corral area and host the Loma Marcelo Ca/Mg skarn, composed of calc-silicate- and chondrodite-bearing assemblages. Petrographical, geochemical, and geochronological data indicate that the skarn was formed from carbonate xenoliths of sedimentary nature incorporated during the intrusion of the Neoproterozoic granites and that it is the result of three successive metamorphic events. The first one is related to the incorporation of carbonate xenoliths by the intrusion and the associated contact metamorphism. The second event is linked to the crystallization of the Early Cambrian granites and related post-magmatic processes. They are responsible for fluorine influx into the Neoproterozoic basement, which resulted in the formation of high-F minerals in the Loma Marcelo skarn ( e.g. vesuvianite, chondrodite). The Sm-Nd garnet-whole rock isochron age of 526.8 ± 12.0 Ma in the skarn confirms its relationship with the Early Cambrian magmatism. The last event corresponds to a regional metamorphism assigned to the Late Devonian–Early Carboniferous on the basis of a LA-ICP-MS U-Pb age of 353.4 ± 6.7 Ma determined on zircons of the skarn as well as a Rb-Sr quartz-sericite isochron age of 364.4 ± 3.6 Ma obtained from a quartz vein that post-tectonically cuts the already mylonitized granites. The different chemical compositions of the carbonate protoliths determined the formation of two types of skarns of calcic and magnesian compositions. A single date of the calcic skarn defined a LA-ICP-MS U-Pb upper intercept age of 648 ± 21 Ma, providing the maximum sedimentation age for the calcic protolith of the Loma Marcelo skarn. The minimum sedimentation age is provided by the crystallization age of the S-type granite surrounding the skarn ( ca. 607 Ma). The Loma Marcelo skarn reveals the occurrence of underground Neoproterozoic carbonate (meta-?) sedimentary rocks as part of the basement of the Ventania System. These rocks could correlate with the carbonate sequences of the neighbouring Claromecó Basin and Tandilia System. [ABSTRACT FROM AUTHOR]

In general, the detection of F and other halogens is challenging through conventional techniques. In this paper, various approaches for the qualitative and quantitative analysis of F using the laser-induced breakdown spectroscopy (LIBS) technique were demonstrated. In LIBS, fluorine detection can be realized by means of atomic lines and molecular bands. For the purposes of our experiment, two sets of pellets with various contents of CaF2, CaCO3 and cellulose were analyzed using a lab-based LIBS system under a He atmosphere. The fluorine atomic line at 685.60 nm was correlated with CaF signals proving their close relationship. Consequently, the limits of detection were determined for both analytical signals. Moreover, conditions necessary for the quantification of F via CaF band signals were estimated. The dependence of the CaF signal on the varying ratio of Ca and F contents was investigated. Finally, a chip of a real CaF2 crystal was prepared and its surface was mapped with Raman and LIBS systems. The obtained elemental and molecular maps showed good numerical correlations. Thus, the yielded results validated the possibility to substitute the fluorine atomic line by non-conventional CaF molecular bands in the qualitative and quantitative LIBS analysis of fluorine. [ABSTRACT FROM AUTHOR]

Strong hydrogen bonds play a significant role in crystal packing. In particular, the involvement of interactions involving fluorine in controlling the crystal packing requires appropriate attention, especially in the presence of other strong hydrogen bonds. In the present study, a detailed quantitative assessment has been performed of the nature, energetics and topological properties derived from the electron density in model compounds based on fluorinated benzamides (a total of 46 fluorine-substituted benzamides containing multiple fluorine atoms) in the solid state. The primary motivation in the design of such molecules is to enhance the acidity of the interacting H atoms in the presence of an increasing number of F atoms on the molecular scaffold, resulting in increased propensity towards the formation of intermolecular interactions involving organic fluorine. This exercise has resulted in the identification of new and frequently occurring supramolecular synthons involving F atoms in the packing of molecules in the solid state. The energetics associated with short and directional intermolecular C sp2-H...F-C sp2 interactions with significantly high electrostatic contributions is noteworthy, and the topological analysis reveals the bonding character of these ubiquitous interactions in crystal packing in addition to the presence of C sp2-F...F-C sp2 contacts. [ABSTRACT FROM AUTHOR]

The layered aluminum-based composite which was synthesized by co-precipitation followed by calcining the precursor at 450 °C under N 2 atmosphere has been used to remove fluorine ion from industrial zinc sulfate solution. The composite was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and BET specific surface area analysis. The effect of adsorption temperature, dosage of absorbent, contact time and the adsorption kinetics were investigated. The kinetics data suggests that the process of adsorption could be described by the pseudo-second-order kinetic model. The adsorption isotherm fits the Langmuir isotherm model well and the theoretical maximum adsorption capacity was 5.62 mg/g. Furthermore, the adsorption mechanism was studied by Energy dispersive analysis of X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR). The result shows that the distribution of F element is associated with Al element after adsorption and the hydroxyl could exchange with fluorine ion, revealing an ion exchange mechanism. The regeneration study shows that the adsorbent could be reused by a simple method of Alkali washing followed by pickling. [ABSTRACT FROM AUTHOR]

The chemical synthesis and characterization with spectroscopic and electrochemical properties of [bis(4-fluorophenyl)-methoxy]-substituted metallo-phthalocyanines were reported for the first time. The new phthalocyanines have been characterized by elemental analysis, UV-Vis, FT-IR, and mass spectroscopies. The aggregation behavior of the phthalocyanine compounds was investigated in different solvents and concentrations. It is found that the fluoro substituents of peripherally Co and Cu complexes are examined and induce a shift to the redox processes toward the negative potentials and formed more reversible processes. Metal-based reduction and oxidation reactions were obtained for the Co(II) complex, whereas Cu(II) complexes exhibited Pc-ring-based electron-transfer reactions. The voltammetric measurements supported the proposed structure of the complexes. [ABSTRACT FROM PUBLISHER]

The contamination status of perfluoroalkyl substances (PFASs) were investigated in 64 tapwater samples collected from 17 cities and 45 surface water samples from adjacent areas in the eastern China. The total PFAS concentrations in tapwater ranged from 1.4 to 175 ng/L; relatively higher PFAS levels were observed in samples collected from the Yangtze River Delta region, which was similar to the geographical distribution pattern of PFAS levels observed in rivers and lakes. The highest total PFASs in tapwater was found in Changshu, where several fluorine-related industries are located, whereas the lowest was observed in Beijing. Significant positive correlations between PFAS compositions in tap water sample and their source waters were noted. Several industries such as paper, textile, and leather industries may contribute to the contamination of PFASs in tapwater. [ABSTRACT FROM AUTHOR]

The feasibility of the electrokinetic treatment for the removal of fluorine from the red mud was evaluated. Three electrokinetic experiments were conducted in a self-made electrokinetic apparatus with deionized water as electrolyte, and the potential gradient was set at 0.5, 1.0 and 1.5 V/cm respectively. The effects of the potential gradient on the removal of fluorine and the chemicophysical properties of the red mud were investigated. The results revealed that the fluorine content in the red mud decreased gradually and the red mud properties such as pH and electrical conductivity (EC) were significantly redistributed from the cathode to the anode regions after the electrokinetic treatment. Among the given potential gradients the removal rate of fluorine increased with the potential gradient. 1.5 V/cm had the highest removal rate 63.2% and 1.0 V/cm had very significant and steady electroosmotic flow (EOF). This research shows that the electrokinetic treatment is a novel technique that has high efficiency and promising application for the removal of fluorine from the red mud. [ABSTRACT FROM AUTHOR]

We have performed refining process of yttrium (Y) by removal of fluorine (F) residually existing in commercial Y metal. It was demonstrated that combination of conventional plasma arc melting and mechanical surface polishing is a powerful method for removal of F, the residual concentration of which was traced by energy dispersive X-ray spectroscopy of as processed material and X-ray photoemission spectroscopy of as deposited films, which were grown using the processed material as a deposition source. As a result, the concentration of F in our purified material was assessed to be smaller than 3.5 wt ppm, which is approximately 1.3 % of the initial F concentration present in the unpurified material (260 wt ppm). [ABSTRACT FROM AUTHOR]

We dissected halogen-aryl π interactions experimentally using a bicyclic N-arylimide based molecular torsion balances system, which is based on the influence of the non-bonded interaction on the equilibria between folded and unfolded states. Through comparison of balances modulated by higher halogens with fluorine balances, we determined the magnitude of the halogen-aryl π interactions in our unimolecular systems to be larger than −5.0 kJ mol−1, which is comparable with the magnitude estimated in the biomolecular systems. Our study provides direct experimental evidence of halogen-aryl π interactions in solution, which until now have only been revealed in the solid state and evaluated theoretically by quantum-mechanical calculations. [ABSTRACT FROM AUTHOR]