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This paper reports on the effect of different contents of fluorine on the thermal stability of glasses in the SiO 2 –MgO–CaO–Na 2 O–F system. Four glass compositions, with experimental fluorine contents varying from 2.12 to 4.39 wt.%, were studied using differential scanning calorimetry (DSC). The devitrification behavior was assessed through the evaluation of both the glass stability (GS) and glass-forming ability (GFA) using different parameters calculated from the characteristic temperatures in non-isothermal DSC curves. The predominant crystallization mechanism was determined by the difference in the crystallization temperature (Δ T p ) between fine and coarse glass samples. The results indicate that the studied melts exhibit a low tendency to devitrify during cooling, although this trend is increased with the fluorine content. The glass thermal stability is affected by the particle size, with it being easier to crystallize a glass powder sample than a coarse glass sample. The surface crystallization mechanism is predominant at the beginning of the devitrification process; however, the volume crystallization acquires importance with an increase in the fluorine content. [ABSTRACT FROM AUTHOR]

The quantification of the different parameters influencing He diffusion in apatite is an important issue for the interpretation of (U-Th)/He thermochronometric ages. Key issues include understanding the role of chemical composition and the mechanism modifying diffusivity by radiation damage, both requiring a realistic description at the atomic level. In this contribution, we restrict ourselves on the influence of the chemical composition especially on the effect of Cl-atoms on the He diffusion in the damage-free apatite crystal. For this purpose, a multi-scale theoretical diffusion study has been conducted using periodic Density Functional Theory calculations for two different apatite compositions (pure fluorine apatite and apatite with one chlorine and 3 fluorine atoms per cell called Cl 0.25 -apatite) representative of damage-free crystals. Different He insertion sites and diffusion pathways are first investigated. The Density Functional Theory approach coupled to the Nudged Elastic Band method is used to determine the energy barriers between the insertion sites. A statistical method, based on Transition State Theory, is used to compute the jump rate between sites and the different results are used as output for a 3D random walk simulation, which determines the diffusion trajectories and the diffusion coefficients. The calculated diffusion coefficients for pure F-apatite exhibit a slightly anisotropic behavior with an activation energy E a = 95.5 kJ/mol and a frequency factor D 0 = 1.9 × 10 −3 cm 2 /s along the c axis; E a = 106.1 kJ/mol and D 0 = 4.1 × 10 −3 cm 2 /s in the plane orthogonal to c . Closure temperatures for a 60 μm grain radius and 10 °C/Ma cooling rate range from 33 to 36 °C and depend on crystal geometry for a given grain size. Surprisingly, even though He diffusion is strongly blocked across the Cl atoms in Cl 0.25 -apatite, where E a is significantly higher (166.7 kJ/mol), He atoms can still diffuse along the c axis through workaround pathways. Closure temperatures are dependent on the Cl content in the crystal lattice and can be ∼12 °C higher for Cl 0.25 -apatite than for F-apatite. These results show that various Cl contents lead to a more He retentive diffusivity in addition to their impact on damage-annealing rate. The results of this study are in good agreement with experimental results and demonstrate that a proper Density Functional Theory treatment allows to characterize He diffusion in damage-free apatite. This opens new avenues to a reliable method of quantifying rare gas diffusion in mineral structures. [ABSTRACT FROM AUTHOR]

The concentrations of volatile elements in the moon have important implications for the formation of the earth–moon system. There is currently a debate regarding the water content of the lunar mantle: Authors studying H 2 O in lunar pyroclastic glass beads and in olivine-hosted melt inclusions in such pyroclastic samples and in plagioclase crystals in lunar highland anorthosites infer hundreds of ppm H 2 O in the lunar mantle. In contrast, authors studying Zn/Fe ratios infer that the H 2 O concentration in the lunar mantle is ≤ 1 ppm , and they argue that the glassy lunar basalts are a local anomaly. We contribute to a resolution of the debate by a broader examination of the concentrations of H 2 O and other volatile components in olivine-hosted melt inclusions in a wider range of lunar mare basalts, including crystalline melt inclusions that are homogenized by melting in the laboratory. We find that F, Cl, and S concentrations in various lunar melt inclusions (including those in glassy lunar basalts) are similar to one another, and previously studied glassy lunar basalts are not a local anomaly in terms of these volatile concentrations. Furthermore, we estimate the pre-degassing H 2 O/Ce, F/Nd, and S/Dy ratios of mare basaltic magmas to be at least 64, 4.0 and 100 respectively. These ratios are lower than those of primitive earth mantle by a factor of 3, 5, and 4 respectively. The depletion factors of these volatile elements relative to the earth's primitive mantle do not correlate strongly with volatility or bonding energy, and indeed they are roughly constant and similar to those of other volatile elements such as Li, Cs, Rb and K. This approximate constancy of volatile depletion in the moon relative to the earth can be explained by assuming that both the earth and the moon acquired volatiles from a similar source or by a similar mechanism but the earth was more efficient in acquiring the volatiles. We estimate the H 2 O, F and S concentrations in the primitive lunar mantle source to be at least 110, 5.3, and 70 ppm, respectively – similar to or slightly lower than those in terrestrial MORB mantle. [ABSTRACT FROM AUTHOR]

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A quantitative fluorine NMR (19F qNMR) method was developed to determine the carbohydrate density on glyconanomaterials. Mannose (Man)- and galactose (Gal)-conjugated silica nanoparticles (SNPs) were synthesized from perfluorophenyl azide (PFPA)-functionalized SNPs and propargylated Man or Gal by copper-catalyzed azide-alkyne cycloaddition (click reaction). After treating PFPA-SNPs or Man-SNPs with hydrofluoric acid followed by lyophilization, the remaining residues were directly subjected to 19F NMR analysis. The density of PFPA on PFPA-SNP was determined to be 7.7 ± 0.2 × 10-16 nmol/nm² and Man on Man-SNP to be 6.4 ± 0.2 × 10-16 nmol/nm² giving a yield of ~83% for the click coupling reaction. The apparent dissociation constant (Kd) of Man-SNPs with fluorescein isothiocyanate (FITC)-concanavalin A (Con A) was determined using a fluorescence competition assay to be 0.289 ± 0.003 µM, which represents more than 3 orders of magnitude affinity increase compared to free Man with Con A. [ABSTRACT FROM AUTHOR]

The potential energy profile for the F+(H2O)3→HF+(H2O)2OH reaction has been investigated using the 'gold standard' CCSD(T) method with correlation-consistent basis sets up to cc-pVQZ. Four different reaction pathways have been found and these are related, both geometrically and energetically. The entrance complexes F⋅⋅⋅(H2O)3 for all four reaction pathways are found lying ca. 7 kcal mol−1 below the separated reactants F+(H2O)3. The four reaction barriers on their respective reaction coordinates lie ca. 4 kcal mol−1 below the reactants. There are also corresponding exit complexes HF⋅⋅⋅(H2O)2OH, lying about 13 kcal mol−1 below the separated products HF+(H2O)2OH. Compared with analogous F+(H2O)2 and F+H2O reactions, the F+(H2O)3 reaction is somewhat similar to the former but qualitatively different from the latter. It may be reasonable to predict that the reactions between atomic fluorine and water tetramer (or even larger water clusters) may be similar to the F+(H2O)3 reaction. [ABSTRACT FROM AUTHOR]

The 19 F(p,  α 0 ) 16 O reaction at low energies plays an important role in fundamental physics. In particular in nuclear astrophysics it represents, together with the 19 F(p,  γ ) 20 Ne reaction, the crossing point between the CNO and the NeNa cycles in stars. Further, in hydrogen-rich stellar environments, it is the most important fluorine destruction channel. In this paper we report new measurements on the 19 F(p,  α 0 ) 16 O reaction at deeply sub-Coulomb energies (0.2–0.6 MeV), a region where, despite the key role of this reaction, very few and old data are reported. The deduced astrophysical S -factor is ≈ 1.5 – 2 times larger than currently adopted extrapolations with possibly important astrophysical consequences. [ABSTRACT FROM AUTHOR]

The development of a safe and efficient method for the degradation of SF6 is of current environmental interest, because SF6 is one of the most potent greenhouse gases. SF6 is thermally and chemically extremely inert, and therefore, it has been used in various industrial applications. However, this inertness results in a major challenge for its depletion. We report on a process for a catalytic degradation of SF6 in the homogeneous phase by using rhodium complexes as precatalysts. The SF6 activation reactions feature mild reaction conditions, low catalyst loadings, and a high selectivity. The employment of phosphines and hydrosilanes for scavenging the sulfur and fluorine atoms of the SF6 molecule allows the selective transformation of SF6 into nongaseous and nontoxic compounds. [ABSTRACT FROM AUTHOR]

The programmed type I cell death, defined as apoptosis, is induced by complex regulated signaling pathways that trigger the intracellular activation of executioner caspases-3, -6 and -7. Once activated, these enzymes initiate cellular death through cleavage of proteins which are responsible for DNA repair, signaling and cell maintenance. Several radiofluorinated inhibitors of caspases-3 and -7, comprising a moderate lipophilic 5-(1-pyrrolidinylsulfonyl)isatin lead structure, are currently being investigated for imaging apoptosis in vivo by us and others. The purpose of this study was to increase the intrinsic hydrophilicity of the aforementioned lead structure to alter the pharmacokinetic behavior of the resulting caspase-3 and -7 targeted radiotracer. Therefore, fluorinated and non-fluorinated derivatives of 5-(1-pyrrolidinylsulfonyl)-7-azaisatin were synthesized and tested for their inhibitory properties against recombinant caspases-3 and -7. Fluorine-18 has been introduced by copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) of an alkyne precursor with 2-[ 18 F]fluoroethylazide. Using dynamic micro-PET biodistribution studies in vivo the kinetic behavior of one promising PET-compatible 5-pyrrolidinylsulfonyl 7-azaisatin derivative has been compared to a previously described isatin based radiotracer. [ABSTRACT FROM AUTHOR]

Objective and Background: Fluoride is an element widely found in the earth crust. Advantages and disadvantages of fluoride in the human body are depended on its concentration. Long-term consumption of drinking water contaminated with arsenic can cause adverse health effects such as skin lesions and cancer in humans. The aim of this study was to study efficiency of nano alumina on multi walled carbon nano tube for removal As(V) and fluoride from aqueous solution. Materials and Method: In this study, nano-scale crystalline alumina was synthesized on single walled carbon nanotube by sol-gel method for using as a sorbent for solid phase extraction of Fluorine ion and arsenic(V). Response surface methodology based on Box-Behnken was used to assess the effect of independent variables on the response function and prediction of the best response value. In this study, effect of different parameters, such as contact time (10 to 120 min), pH (3-9), adsorbent dosage (0.25-1.5 g/L) and initial concentration of fluoride (2-8 mg/L) on efficiency of process was investigated. The structure of nano-scale alumina on multi walled carbon nano tube was determined by XRD and SEM techniques. Moreover, Freundlich and Langmuir isotherm models were used to calculate equilibrium constant. Results: It was found that by increasing contact time and adsorbent dosage the rate of fluoride removal increased. However, by increasing pH and initial concentration the efficiency of fluoride removal decreased. High value for R2 (0.94) shows that removal of arsenic(V) can be described by this model. The Freundlich isotherm was the best fitted graph for experimental data with R2 more than 0.997. Conclusion: In this study, it was observed that efficiency of arsenic(V) and fluoride removal was greatly increased by using nano-scale alumina on multi walled carbon nanotubes (MWCNTs). [ABSTRACT FROM AUTHOR]

ABSTRACT The study was conducted to investigate oxidative stress, apoptosis, and protein expressions of caspase-3, 8, and 9 in kidney of the carp juveniles exposed to 0, 40, 80, 120, and 160 mg L−1 of fluoride (in the form of NaF) for 90 days. The results showed that dose- and time-dependent decrease of SOD and GSH and dose- and time-dependent increase of MDA were observed in the carp juveniles, which suggested that fluoride induced oxidative damage accompanied with morphological changes and significant apoptosis in fish exposed to fluoride, especially in the higher doses. Fluoride exposure also significantly elevated the protein expressions of caspase-3, 8, and 9. In conclusion, these results indicate that chronic exposure to fluoride causes oxidative stress, damages the kidney structure, and results in renal apoptosis by caspase-dependent pathway. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 769-781, 2015. [ABSTRACT FROM AUTHOR]

In this paper, the triangular fuzzy numbers theory is introduced to health risk assessment. On the basis of defining the parameters as triangular fuzzy numbers, uncertain models were established. As a case study, the fuzzy models were applied to evaluate the health risk of arsenic and fluorine in groundwater in western Jilin Province. The evaluation results indicated that there was great carcinogenic risk of arsenic in Quaternary phreatic water, Quaternary confined water, and Tertiary confined water, and the most probable risk values were 20.94 × 10, 55.22 × 10, and 24.02 × 10 a, respectively; all of these values are greater than 5.0 × 10 a, the acceptable maximum value recommended by the International Agency for Research on Cancer (IARC). The most probable risk values of fluorine in Quaternary phreatic water, Quaternary confined water, and Tertiary confined water were 3.64 × 10, 2.48 × 10, and 2.17 × 10 a, respectively, all of which are less than the acceptable maximum value recommended by IARC. The assessment results showed that groundwater in the study area posed great health risks, and the fuzzy models reveal the health risk state of hazardous substances in groundwater more scientifically than traditional models. [ABSTRACT FROM AUTHOR]

Transparent conducting oxides (TCOs) are used as electrodes in dye-sensitized solar cells (DSSCs) because of their properties such as high transmittance and low resistivity. In the present work, the effects of swift heavy ion (SHI) irradiation on various types of TCOs are presented. The objective of this study is to investigate the effect of SHI on TCOs. For the present study, three different types of TCOs are considered, namely, (a) FTO (fluorine-doped tin oxide, SnO 2 :F) on a Nippon glass substrate, (b) ITO (indium tin oxide, In 2 O 3 :Sn) coated on polyethylene terephthalate (PET) on a Corning glass substrate, and (c) ITO on a Corning glass substrate. These films are irradiated with 120 MeV Ag +9 ions at fluences ranging from 3.0 × 10 11 ions/cm 2 to 3.0 × 10 13 ions/cm 2 . The structural, morphological, optical and electrical properties are studied via X-ray diffraction (XRD), atomic force microscopy (AFM), UV–Vis absorption spectroscopy and four-probe resistivity measurements, respectively. The ITO-PET electrode is found to exhibit superior conductivity and transmittance properties in comparison with the others after irradiation and, therefore, to be the most suitable for solar cell applications. [ABSTRACT FROM AUTHOR]

The analytical capabilities of a glow discharge (GD) as a secondary source for excitation/ionization of the material provided by laser ablation (LA) have been compared to conventional laser induced breakdown spectroscopy (LIBS). In LA–GD both sources can be independently adjusted to optimize the sampling process and then its subsequent excitation. This could involve a number of analytical performance advantages, such as reduced matrix dependence, greater precision and sensitivity than those encountered in LIBS. For such purpose, an ablation chamber design including two electrodes to generate the GD discharge has been built and assayed. A comparison between LIBS and LA–GD–OES has been carried out, both, under reduced argon and helium atmospheres. Different sets of samples (conducting reference materials, glass and fluorine pellets) have been used to evaluate the novel coupled technique. The LA–GD coupled system has shown to provide lower detection limits. In addition, best linear correlations between intensities and concentrations and lower matrix effects have also been found using the coupled system. Moreover, special advantages of the LA–GD–OES have also been demonstrated for the analysis of fluorine. [ABSTRACT FROM AUTHOR]

This paper describes a new methodology for the analysis of fluorine in glasses and glazes by wavelength-dispersive x-ray fluorescence (WD-XRF) spectrometry. The methodology was developed in order to have a rapid and reliable method, that could be used as a control method. Fluorine-containing glasses and glazes are of interest for a broad range of components, and it has been shown that the introduction of fluoride ions into phosphate glasses has an effect on the structural and optical properties of the glass, so it is necessary to know the fluorine content in this type of glasses in order to predict these optical properties. Besides, in the ceramic industry fluorine is used as an opacifying agent. There are different methodologies for determining the fluorine content in this kind of sample, based on digestion of the sample; the methods exhibit serious interferences and/or problems of loss of the analyte, apart from being tedious and time consuming. In order to develop the methodology, the different process stages, ranging from sample preparation to measurement conditions were optimized; the method was validated by analysing reference materials with known fluorine content and samples that had been analysed by an independent method (potentiometry). The fine-tuned methodology permits the analysis of fluorine concentration, with samples prepared in the form of beads. The method allows the determination of fluorine in a relatively short time in any glasses and glazes and presents low uncertainties with a quantification limit of 0·1% (by weight). [ABSTRACT FROM AUTHOR]

A new available multi-analyte fluorescent sensor based on a bisphenol A-quinoline conjugate ( BFQ) was synthesized in two facile steps and was characterized systematically. BFQ exhibited an effectively selective and sensitive recognition toward Znand Al cations in EtOH-HO ( v/v = 9/1) over other cations and F anion in CHCN over other anions with remarkably enhanced fluorescent intensities. According to the quantum yield (Φ) measurements, BFQ-Zn, BFQ-Al and BFQ-F complexes showed 16, 22 and 30 times higher Φ values than BFQ, respectively. The complexation properties of BFQ with Zn, Al and F ions were also examined by H NMR titration experiments. [ABSTRACT FROM AUTHOR]

The fluorine content of polymer particles labelled with 2,2,2-trifluoroethylamine was reliably quantified with overlapping sensitivity ranges by XPS and solid-state NMR. This provides a first step towards reference materials for the metrological traceability of surface group quantifications. The extension of this concept to fluorescence spectroscopy is illustrated. [ABSTRACT FROM AUTHOR]

Transformer-coupled toroidal plasma (TCTP) has found applications in versatile fields as a high-power-density plasma source. However, most research on TCTP has focused on plasma states in the TCTP, without any change in reactor structures. Therefore, in this paper, we present a study on the effects of inner-surface modification of a TCTP reactor on plasma conditions. Using two types of reactors with different inner surfaces, the silicon-wafer etch rate by fluorine atoms from dissociated NF 3 gas molecules is compared. Then a computer simulation, which derives various plasma parameters, is carried out. As a result, the TCTP reactor with a grooved inner surface shows a higher etch rate than the reactor with a normal inner surface. The computer simulation suggests the reason for this etch rate difference is that the reactor with the grooved inner surface structure has a higher neutral gas temperature than the reactor with the normal inner surface so that more pyrolytic dissociation, resulting in a higher fluorine atom density, is achieved. Our results may be useful for those fields that require a higher neutral temperature or a higher degree of pyrolysis. [ABSTRACT FROM AUTHOR]

For more than three decades, the ability of a fluorine atom involved in a C-F bond to act as a hydrogen-bond acceptor has been a controversial issue. Throughout the years, more and more evidence has been published to support this hypothesis and it is now difficult to doubt the existence of the hydrogen bond with organic fluorine. However, since this interaction has low binding energies, it is sometimes difficult to clearly demonstrate its presence or effect in a system. In the present review, only the most recent examples from the literature are presented and the different techniques used to prove the presence of these C-F···H-X hydrogen bonds are compared and discussed according to the accepted criteria for hydrogen bonding detailed by a recent IUPAC committee. Even with its weak interaction energy, hydrogen bonds to organic fluorine have the potential to affect properties of practical systems in different spheres of chemistry. All the recent examples of such effects are highlighted. 1 Introduction 2 Properties 3 C(sp²)-F 3.1 O-H as Donor 3.2 N-H as Donor 3.3 C(sp²)-H as Donor 3.4 C(sp³)-H as Donor 4 C(sp³)-F 4.1 O-H as Donor 4.2 N-H as Donor 4.3 C(sp²)-H as Donor 4.4 C(sp³)-H as Donor 5 Conclusion [ABSTRACT FROM AUTHOR]

Kinetic model simulations of charge carrier transport following irradiation of LiF:Mg,Ti (TLD-100) including Fluorine vacancy/F center creation by the radiation and dose-dependent vacancy-interstitial recombination are presented which describe the experimentally measured linear/exponentially saturating optical absorption dose response of the electron trapping centers at 4.0 eV, 4.77 eV, 5.08 eV (F band) and 5.45 eV. Linear/exponentially saturating dose response is commonly observed for centers which are not created by the radiation. The creation of Fluorine vacancies by the radiation could therefore be expected to lead to a supralinear dose response of the F center before the onset of saturation. Nonetheless, the dose response is linear from 10 Gy to 500 Gy and can be fitted with a dose-filling constant β = 6.1 · 10 −5 Gy −1 corresponding to a 5% and 25% decrease from linearity at 10 3 Gy and 5 · 10 3 Gy respectively. The model attempts to resolve a central question concerning the mechanisms leading to the linear/exponentially saturating dose response of the F band even though Fluorine vacancies are being continuously created during the irradiation. The electron-trapping characteristics of the created vacancies are assumed to differ somewhat from the vacancies originally present in un-irradiated samples due to differences in their immediate environment. Vacancy-interstitial recombination for separation distances less than a critical distance, d c is demonstrated to be significant for D > 500 Gy ( d c = 36 Å) and is an important mechanism contributing to the F center saturation at high dose-levels. The kinetic model accurately simulates the experimentally observed F center dose response over the entire investigated dose range of 10–10 5 Gy under the following conditions: (i) The concentration of vacancies initially present is unexpectedly high at ∼10 23 m −3 , possibly due to the highly doped, non-crystalline and hot-pressed nature of the LiF:Mg,Ti samples. (ii) The transition probability, A n4o , for electron capture into the initially-present vacancies is ∼40 times greater than A n4 , the transition probability for the radiation-created vacancies. These two factors marginalize the effect of the created vacancies at low dose resulting in a linear dose response. [ABSTRACT FROM AUTHOR]

We report the synthesis of novel, potentially hypnotic fluorine-substituted phenyl acetate derivatives. We describe the structure–activity relationship that led us to the promising derivative: ethyl 2-(4-(2-(diethylamino)-2-oxoethoxy)-5-ethoxy-2-fluorophenyl) acetate ( 55 ). The unique pharmacological features of compound 55 are its relatively high affinity for the GABA A receptor, together with a unique affinity for the NMDA receptor, different to propanidid and AZD3043. In animal models, compound 55 showed stronger hypnotic potency and longer duration of LORR than propanidid and AZD3043, but also maintained a rapid recovery time to walking and behavioral recovery. In particular, compound 55 displayed reflex depression during infusion. [ABSTRACT FROM AUTHOR]

To study the effects of fluorine substituent of polystyrene (PSt) on gradient-index fiber-optic properties, a poly(para-fluorostyrene) (P(p-FSt))-based graded-index plastic optical fiber (GI POF) is fabricated, and its properties are compared with those of a PSt-based GI POF. The para-fluorine substitution positively affects the glass transition temperature ( T g ) of the core, wavelength dispersion of the optimum refractive index profile, bandwidth, and attenuation. The core T g of the P(p-FSt)-based GI POF is 88 °C, which is higher than that of the PSt-based GI POF by 9 °C when both fibers have an identical numerical aperture (NA = 0.2). The optimum refractive index profile coefficient for the P(p-FSt)-based GI POF varies from 2.2 to 2.1 in the 600–800 nm range, whereas that for the PSt-based GI POF varies from 2.6 to 2.3 in the same wavelength region. The bandwidth of the P(p-FSt)-based GI POF is intrinsically higher than that of PSt-based GI POF. Moreover, the fiber attenuation of the P(p-FSt)-based GI POF was significantly smaller than that of the PSt-based GI POF over the source wavelength range. Our study demonstrates that P(p-FSt) has favorable properties as a GI POF base material. [ABSTRACT FROM AUTHOR]

Paints are widely used in indoor settings yet there are no data for volatile per- and polyfluoroalkyl substances (PFAS) for paints or knowledge if paints are potentially important sources of human exposure to PFAS. Different commercial paints ( n = 27) were collected from local hardware stores and analyzed for volatile PFAS by gas chromatography-mass spectrometry (GC-MS), nonvolatile PFAS by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-qTOF), and total fluorine by 19 F nuclear magnetic resonance spectroscopy (NMR). Diluted paint required clean up to remove 6:2 fluorotelomer phosphate diester (diPAP), which thermally transforms into 6:2 FTOH at 280 °C (GC inlet temperature). Only 6:2 FTOH (0.9-83 μg/g) and 6:2 diPAP (0.073-58 μg/g) were found in five exterior and nine interior paints and only accounted for a maximum of 17% of total fluorine. Upon drying, 40% of the FTOH mass was lost, and the loss was verified by measurements of the cumulative FTOH mass measured in the air of a small, confined space over a 3 h period. Based on the liquid paint results, the ConsExpo model was used for potential exposure assessment and one commercial paint exceeded the chosen reference dose (5 μg/kg-day) for children and adults, indicating the potential for human exposure during painting.

The waste-to-energy (WTE) incinerator plant located in the Turin area (Italy) started to recover energy from the combustion of municipal solid waste in 2013. A health surveillance program was implemented to evaluate the potential health effects on the population living near the plant. This program included a longitudinal biomonitoring to evaluate temporal changes of some environmental pollutants, including polycyclic aromatic hydrocarbons (PAHs), in residents living in areas near the Turin incinerator (exposed group, E) compared to those observed in subjects living far from the plant (not exposed group, NE). Ten monohydroxy-PAHs (OH-PAHs), consisting in the principal metabolites of naphthalene, fluorine, phenanthrene, and pyrene, were analyzed in urines collected from the E and NE subjects after one (T 1 ) and three years (T 2 ) of plant activity and compared with those determined in the same cohort established before the plant start-up (T 0 ). Spearman correlation analysis was undertaken to explore possible associations between OH-PAHs and personal characteristics, lifestyle variables, and dietary habits. A linear mixed model (LMM) approach was applied to determine temporal trends of OH-PAHs observed in the E and NE subjects and to evaluate possible differences in trend between the two groups. Temporal trends of OH-PAHs determined by LMM analysis demonstrated that, at all times, the E group had concentrations lower than those assessed in the NE group, all other conditions being equal. Moreover, no increase in OH-PAH concentrations was observed at T 1 and T 2 either in E or in NE group. Significant positive correlations were found between all OH-PAHs and smoking habits. Regarding variables associated to outdoor PAH exposure, residence near high traffic roads and daily time in traffic road was positively correlated with 1-hydroxynaphthalene and 1-hydroxypyrene, respectively. In conclusion, no impact of the WTE plant on exposure to PAHs was observed on the population living near the plant., 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 © 2022 Elsevier Ltd. All rights reserved.)

Recent studies aiming at a fluorine mass balance analysis in sediments combined the determination of extractable organic fluorine (EOF) with target analysis. They reported high fractions of unidentified organic fluorine (UOF) compounds, as the target analysis covers only a limited number of per- and polyfluoroalkyl substances (PFAS). For this reason, in this study, a comprehensive approach was used combining target analysis with an extended PFAS spectrum, the EOF and a modified total oxidisable precursor (TOP) assay, which includes trifluoroacetic acid, to determine the PFAS contamination in sediments (n=41) and suspended solids (n=1) from water bodies in Northern Germany (Lower Saxony). PFAS are ubiquitous in the sediments (detected in 83% of the samples). Perfluorinated carboxylic acids (PFCAs) were found in 64% of the samples; perfluorinated sulfonic acids (PFSAs) were detected less frequently (21%), with the highest concentration observed for perfluorooctanesulfonic acid (PFOS). Levels of precursors and substitutes were lower. Applying the TOP assay resulted in an increase in PFCAs in 43% of the samples analysed. In most cases, target analysis and the TOP assay could not account for the EOF concentrations measured. However, as the fraction of UOF decreased significantly, the application of the TOP assay in fluorine mass balance analysis proved to be an important tool in characterising the PFAS contamination of riverine sediments., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Continuous fluorine (F) accumulation in soil by anthropogenic activities leads to variously global environmental and health issues. Herein, 300 farmland soil samples were collected from different anthropogenic activity dominated districts for studying the distribution and related health risk of F in soils. Co-existing metal concentrations in soil samples were also analysed to evaluate the relationship between the distribution of F and metals in soil. The median value of the total F concentration of 488 mg kg -1 in the present samples was higher than the median background F concentration in topsoil in Sichuan province of China (261 mg kg -1 ). Concentration of water-soluble F (1.33-26.2 mg kg -1 ) was two or three orders of magnitude less than that of total F in soil. Levels of total and water-soluble F in soils collected from the district with longer contamination history were higher than that from other districts with shorter contamination period, indicating a historical contribution of anthropogenic activities to F accumulation in soil. Notable positive correlation between the total F and vanadium (V) concentration in soil can be partly linked to the usually negative charged form or a common source of F and V in soil (e.g. coal combustion). Compared with inhalation and dermal contact, present human exposure of F in soil was mainly caused by oral ingestion, and the health risks posed by F in soil for both children and adults were acceptable. However, considering the higher potential risk for children than adults, the accumulation of F in soil induced by anthropogenic activities should not be neglect., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

The synthesis of a new phthalonitrile ( 1 ), together with photophysical, photochemical and spectral properties of the resulting peripherally octakis zinc, magnesium and oxotitanium phthalocyanines ( 2 , 3 and 4 ) are described for the first time. New compounds 1 – 4 have been synthesized and characterized by elemental analysis, IR, 1 H NMR, mass spectra and electronic spectroscopy. Complexes 2 , 3 and 4 have good solubility in organic solvents such as CHCl 3 , DCM, THF and toluene. In this study, fluorescence quantum yield (photophysic), fluorescence behavior, singlet oxygen quantum and photodegradation quantum yields (photochemistry) and spectral properties of these new complexes were studied in THF. Aggregation was not observed in the presence of a long alkyl chain containing fluorine in the complexes. The effects of metal and the fluoro-functional groups on new peripherally octa-substituted metallo-phthalocyanines on the photophysicochemical parameters of the phthalocyanines ( 2 , 3 and 4 ) were also investigated. [ABSTRACT FROM AUTHOR]

Microscale radiosynthesis on a miniaturized device has been reported as a promising tool for positron emission tomography. Here, we studied miscroscale-level radiosynthetic conditions by examining several microscale reactions that affect the radiochemical yield of 3′-deoxy-3′-[ 18 F]fluorothymidine ([ 18 F]FLT). [ 18 F]FLT was prepared with 3- N -Boc-5′- O -dimethoxytrityl-3′- O -nosyl-thymidine using the cartridge purification method. [ 18 F]FLT was prepared with a yield of 71%, and the product's purity was greater than 99%. Our results provide a new guideline for microscale [ 18 F]FLT radiosynthesis. [ABSTRACT FROM AUTHOR]

Generalized functionality of the fluorine production manufacturing efficiency developed for determination of optimum values of temperature and hydrogen fluoride concentration according to the method of multiparametric optimization allowed calculating the optimum process performance and develop the optimum fluorine production process control by maintaining electrolytic solution temperature and hydrogen fluoride concentration in the electrolyte depending on the value of the current load in the electrolyzer. [ABSTRACT FROM AUTHOR]

The justification of the need to remove fluorine from the complex beryllium-containing concentrates during their treatment before the stage of beryllium hydroxide precipitation is given. The analysis of possible ways of fluorine elimination from beryllium raw materials has been carried out. [ABSTRACT FROM AUTHOR]

The article presents the method of recycling aluminum industry fluorine-containing waste products to produce hydrogen fluoride. We carried out the estimate of the thermodynamic parameters of sulfuric acidic recycling of fluorine-containing waste products. We considered the necessity of waste products preliminary oxidizing roast stage to reduce carbonic constituent due to the interaction between carbonic constituent blocks of the sulfuric acid and waste products. We also carried out the researches for kinetic characteristics and to determine the optimal conditions for the to recycle sulfuric acidic in the fluorine-containing waste products. [ABSTRACT FROM AUTHOR]

Based on a physicochemical model of the fluorination of tungsten metal fluorine, we derived an equation for calculating the completeness of the use of fluorine depending on the dimensions of the reaction surface, fluorine feed as well as the temperature and the activity of the tungsten surface, which determine the value. The process of WF 6 synthesis based on two-fold iteration’ the fluorination of tungsten – WF 6 condensation’, which provides the performance of 5.22 kg/hour WF 6 , the completeness of the use of fluorine >99.99% and the emission of harmful gases within maximum permissible concentration. [ABSTRACT FROM AUTHOR]

The article contains the results of studies on the fluorination of rare earth oxides with elemental fluorine, the results of studying the kinetics of the fluorination of a rare earth elements mixture under conditions excluding local overheating and external diffusion inhibition. A serial metallurgical mixture of rare earth oxides of a cerium subgroup manufactured by Sillamäe Mining and Chemical Plant was used as the object of the investigation. The composition and properties of the low-melting fluoride glass for immobilization of solid radioactive and toxic wastes are also given in the article. [ABSTRACT FROM AUTHOR]

In order to investigate the possibility of fluorine removal, processes of sulfuric leaching of the dispersed beryl-bertrandite-phenakite product melted with fluxes, and further thermal treatment have been investigated. The intermediate and final products have been studied by the IR-spectrometry and X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

The 2-[18F]fluoro-3-pent-4-yn-1-yloxypyridine ([18F]FPyKYNE) analog of the potent non-peptide angiotensin II type 1 receptor (AT1R) blocker losartan was produced via click chemistry linking [18F]FPyKYNE to azide-modified tetrazole-protected losartan followed by TFA deprotection. Preliminary small animal imaging with positron emission tomography (PET) in rats displayed high uptake in the kidneys with good contrast to surrounding tissue. Rat metabolism displayed the presence of 23% unchanged tracer in plasma at 30min. Upon co-administration with AT1R blocker candesartan (2.5, 5 and 10mg/kg), a dose-dependent reduction (47-65%) in tracer uptake was observed in the kidney, while no difference was observed following AT2R blocker PD123,319 (5mg/kg), indicating binding selectivity for AT1R over AT2R and potential for imaging AT1R using PET. [ABSTRACT FROM AUTHOR]

To control drugs in vivo, new approaches are needed. Considerable progress has been made towards the applications of fluorine ( 19 F) in pharmacotherapy in this regard. To date, many authors have showed that by using 19 F labelled drugs and non-invasive magnetic resonance imaging (MRI) techniques together, drug biodistribution can be tracked. This review presents methods for 19 F incorporation into pharmaceuticals by forming C–F bonds and drug fluorine oil-water emulsions. Inadequate drug delivery is a major cause of drug resistance, which can be improved using approaches discussed herein aided by 19 F MRI. [ABSTRACT FROM AUTHOR]

Laser induced breakdown spectroscopy (LIBS) is evaluated for detecting fluorine using a commercially available J200 Tandem LA/LIBS system from Applied Spectra, Inc. The 685.6 nm fluorine atomic emission line was used to detect and determine the best calibration method for quantifying the amount of fluorine in a set of prepared NIST SRM 120c phosphate rock standards. The multivariate calibration model, based on partial least squares regression (PLS), provided the best accuracy and precision for the sample set analyzed in this study. The detection limit of fluorine using the J200 LIBS system with a 213 nm laser and an ICCD was determined to be 135 ppm from a phosphate rock standard. A rare earth element (REE)-rich mineral high in fluorine content was used to access the potential applications of mapping the fluorine content over a 16 mm² surface area of the sample. [ABSTRACT FROM AUTHOR]

Highlights: [•] Solid wastes containing uranium were dissolved in hydrochloric acid and water. [•] The decontamination factor of fluorine from uranium became 10–28 by SiO2 treatment. [•] The uranium recovery ratios from solid wastes were more than 80%. [•] The fluorine content of uranium recovered from UF4 was as low as 0.012wt%. [Copyright &y& Elsevier]

Highlights: [•] SnO2 and SnO2:F thin films prepared on glass substrates by ultrasonic spray. [•] Film deposited at different concentration of fluorine from 0wt.% to 12wt.%. [•] Peak corresponding to (200) reveal the direction along the a-axis orientation. [•] Film’s transmission of is over than 83.9%, in visible region. [•] The electrical resistivity decrease with increasing concentration of fluorine. [Copyright &y& Elsevier]

Highlights: [•] A fluorine substituted polymer (PBDTFC10DBT) was synthesized. [•] The PBDTFC10DBT polymer shows a low-lying HOMO energy level as −5.42eV. [•] A PCE of 1.19% was achieved for the polymer solar cell blending with PC61BM. [Copyright &y& Elsevier]

Highlights: [•] A series of new polyfluorinated bis(N-C6F n H5−n -3,5- t Bu2-salicylaldiminato)Cu(II) complexes have been prepared. [•] Conversions of generated Cu(II)–bisphenoxyls to another radicals have been observed. [•] The effect of fluorine atoms on the redox behaviors of Cu(II) complexes was observed. [•] As the number of F atoms increases in ligands and complexes their IC50 values decrease. [•] Crystal structure of bis(N-C6F4H-3,5- t Bu2-salicylaldiminato)Cu has been determined. [ABSTRACT FROM AUTHOR]

Highlights: [•] The two types of boron complexes have been synthesized and characterized. [•] The boron complexes display high stability. [•] The fluorescence efficiencies have been compared for boron complexes. [•] The boron complexes were used for transfer hydrogenation of aromatic ketones. [•] Excellent conversions were achieved when [L 2 BPh 2 ] complexes was used. [ABSTRACT FROM AUTHOR]

Therecombination reactions of CH2Cl radicals with CF3CHF and with CH3CHF radicals were used to generateCF3CHFCH2Cl and CH3CHFCH2Cl molecules with 90–92 kcal mol–1of vibrationalenergy. The experimental rate constants for elimination of HCl andHF and the interchange of Cl and F atoms were measured and comparedto RRKM calculated rate constants to assign the threshold energy foreach unimolecular reaction channel. The Cl/F interchange reactionis approximately 18% of the total unimolecular reaction for both molecules.The product branching ratios and some rate constants also could bemeasured for the unimolecular reactions of the rearranged molecules,CF3CHClCH2F and CH3CHClCH2F. The most important result is that the CH3group lowersthe threshold for Cl/F interchange relative to CH2FCD2Cl, as expected for an electron-density donating group, andthe CF3group, an electron-density withdrawing group, increasesthe threshold energy relative to CH2FCD2Cl.The CH3and CF3groups alter the threshold energiesof the HCl and HF elimination reactions in such a way so as to maintainthe same branching fraction for the interchange reaction. The resultsfrom density functional theory using the B3PW91 method with the 6311+G(2d,p)and G-31G(d′,p′) basis sets are used to discuss thetrends in threshold energies for the Cl/F interchange and the HF andHCl elimination reactions. [ABSTRACT FROM AUTHOR]

Two series of related three-ringnematoges with Δε> 0 and containing 12-vetex carborane (A), 10-vertexcarborane (B), bicyclo[2.2.2]octane (C),cyclohexane (D) and benzene (E) were preparedand investigated as additives to 6-CHBT nematic host and in the pureform (series 2). Dielectric results were analyzed withthe Maier–Meier relationship to gain an understanding of behaviorof additives in nematic solutions. Molecular parameters for each nematogenwere obtained at the B3LYP/6-31G(d,p) level of theory in the host’sdielectric medium, and dielectric data was used as the only experimentalparameter to calculate apparent order parameter Sappand the Kirkwood factor g. The resultsdemonstrated that compounds in series 1stabilize thenematic phase (high Sapp) of the hostmore than additives in series 2(low Sapp), and carbocycles Cand Dare more effective (higher Sapp) thancarborane analogues Aand B(lower Sapp). The method provides insight into behaviorof additives in nematic solutions and is useful for comparative analysisof a series of compounds or a series of hosts. [ABSTRACT FROM AUTHOR]

This work determines the effect of compact TiO2 layers that are deposited onto fluorine-doped tin oxide (FTO), to improve the performance of dye-sensitized solar cells (DSSC). A series of compact TiO2 layers are prepared using radio frequency (rf) reactive magnetron sputtering. The films are characterized using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and UV-Vis spectroscopy. The results show that when the Ar/O2/N2 flow rates are 36:18:9, the photo-induced decomposition of methylene blue and photo-induced hydrophilicity are enhanced. After annealing at 450°C in an atmosphere ambient for 30 min, the compact TiO2 layers exhibit higher optical transmittance. The XRD patterns for the TiO2 films for FTO/glass show a good crystalline structure and anatase (101) diffraction peaks, which demonstrate a higher crystallinity than the ITO/glass films. As a result of this increase in the short circuit photocurrent density, the open-circuit photovoltage, and the fill factor, the DSSC with the FTO/glass and Pt counter electrode demonstrates a solar conversion efficiency of 7.65%. [ABSTRACT FROM AUTHOR]

Analysis data detailing the microstructure of fluorine‐implanted γ‐TiAl alloys are presented. Correlations are done among the shape of the F implant profiles, the F dose, and the quality of the resulting oxide scale after high‐temperature exposure to air. It is shown that good oxidation protection is associated with Gaussian‐type as‐implanted F profiles coupled with optimal F doses over a narrow window of about 5.0–9.0 × 1017 cm−2. [ABSTRACT FROM AUTHOR]

A fluorinated covalent organic framework (COF), named F-COF, was fabricated via simple room-temperature synthesis. With the characteristics of rich fluorine atoms, hydrophobicity, and large conjugated structure, F-COF was evaluated for the extraction of five benzoylurea insecticides (BUs) containing fluorine atoms, benzene ring, and urea bridge. Specifically, F-COF-coated stir bars were prepared by physical adhesion and exhibited higher extraction recovery (73-93 versus 40-85%) toward BUs than commercial stir bars in a shorter extraction time (50 min versus 24 h). The adsorption behavior of BUs on F-COF was explored, and it was assumed that the halogen bond (O-F), hydrophobic interaction, electrostatic interaction, and π-π stacking contributed to the adsorption. On the basis of it, a method combining stir bar sorptive extraction with liquid chromatography-ultraviolet detector was developed for trace analysis of five BUs. Under the optimal conditions, the limits of detection for BUs were found to be 0.301-0.672 μg/L, with the linear range of 1.0/2.0-500 μg/L and relative standard deviations of <8.0% ( c = 5 μg/L and n = 7). The accuracy of the proposed method was validated by the recovery test, and the recoveries of target BUs in spiked pear juice and pear beverage were 82.0-113 and 84.0-112%, respectively.

We analyzed 72 children's textile products marketed as stain-resistant from US and Canadian stores, particularly school uniforms, to assess if clothing represents a significant route of exposure to per- and polyfluoroalkyl substances (PFAS). Products were first screened for total fluorine (total F) using particle-induced γ-ray emission (PIGE) spectroscopy ( n = 72), followed by targeted analysis of 49 neutral and ionic PFAS ( n = 57). PFAS were detected in all products from both markets, with the most abundant compound being 6:2 fluorotelomer alcohol (6:2 FTOH). Total targeted PFAS concentrations for all products collected from both countries ranged from 0.250 to 153 000 ng/g with a median of 117 ng/g (0.0281-38 100 μg/m 2 , median: 24.0 μg/m 2 ). Total targeted PFAS levels in school uniforms were significantly higher than in other items such as bibs, hats, stroller covers, and swimsuits, but comparable to outdoor wear. Higher total targeted PFAS concentrations were found in school uniforms made of 100% cotton than synthetic blends. Perfluoroalkyl acids (PFAAs) precursors were abundant in school uniforms based on the results of hydrolysis and total oxidizable precursor assay. The estimated median potential children's exposure to PFAS via dermal exposure through school uniforms was 1.03 ng/kg bw/day. Substance flow analysis estimated that ∼3 tonnes/year (ranging from 0.05 to 33 tonnes/year) of PFAS are used in US children's uniforms, mostly of polymeric PFAS but with ∼0.1 tonne/year of mobile, nonpolymeric PFAS.

Many solid-phase microextraction (SPME) sorbents have been developed from aerogels because of their low densities, large surface areas, and high porosities. Melamine-formaldehyde (MF) aerogel, made from melamine and formaldehyde by a sol-gel reaction, is one of the typical organic aerogels. MF aerogel has better mechanical strength, chemical stability and extraction performance than inorganic aerogels. The performance of the aerogel is limited in some fields, while composite aerogels can meet different requirements such as good mechanical strength and strong adsorption performance. Graphene oxide (GO) is a two-dimensional nanomaterial composed of a single layer of carbon atoms and provides π-π interaction by a large π-electron. In addition, the oxygen-containing groups at the edge of the lamellar structure improve the hydrophilicity of the material and can interact with various compounds. To improve the extraction performance of MF aerogel for polycyclic aromatic hydrocarbons (PAHs), GO/MF aerogels were prepared by functionalizing MF aerogel with GO. In this study, 1.2612 g of melamine and 80 mg of sodium carbonate were dissolved in 30 mL of water, and the mixture was heated to 80 ℃ under stirring. Then, 2.8 mL formaldehyde solution (37%) was slowly added, and a clear solution was obtained gradually. Next, 50 mg of GO powder was ultrasonically dispersed in 10.0 mL of water and evenly mixed with the above solution. After adjusting the pH to 1.5, the sol-gel process was performed for 48 h, then the gel was aged at room temperature for 24 h. The gel was then soaked in ethanol, acetone, and cyclohexane in turn to replace the solvent. Finally, the GO/MF aerogel was obtained by freeze-drying for 24 h. The GO/MF aerogel was characterized by scanning electron microscopy (SEM) and X-ray photoelectric spectroscopy (XPS), confirming that GO was successfully introduced into MF aerogel, while retaining its three-dimensional network and porous structure. GO/MF aerogel was coated onto the surface of a stainless steel wire to be used as sorbent. Four such wires were placed into a polyetheretherketone (PEEK) tube (0.75 mm i. d., 30 cm length) for in-tube (IT) SPME. The tube was combined with a high-performance liquid chromatography (HPLC) unit to construct an IT-SPME-HPLC online system. When the six-way valve was in the Load state, sample solution achieved online enrichment with analytes while it flowed through the extraction tube. After extraction, the valve was turned to the Inject state, and the analytes were eluted into the chromatographic column by the mobile phase at a flow rate of 1.0 mL/min for separation and detection with the detector. Under the same extraction conditions (sampling volume=30 mL, sampling rate=1.00 mL/min, and concentration of polycyclic aromatic hydrocarbons (PAHs, viz. naphthalene (Nap), acenaphthylene (Acy), acenaphthene (Ace), fluorine (Flu), phenanthrene (Phe), anthracene (Ant), fluoranthene (Fla) and pyrene (Pyr))=5.00 μg/L), GO/MF aerogel-based tube was compared with that of MF aerogel-based tube. GO enhanced the enrichment efficiency of MF aerogel towards PAHs from 1.1 to 2.5 times, due to the increased number of adsorption sites and enhanced π-π interaction with PAHs. IT-SPME was affected by the sampling volume, sampling rate, concentration of organic solvent in sample, desorption solvent, desorption rate, and desorption time. To obtain accurate results, the main extraction and desorption conditions (sampling volume, sampling rate, organic solvent concentration, desorption time) were investigated carefully. As the sampling volume in the extraction tube was increased, the extraction efficiency was found to increase gradually until saturation. In this study, the extraction efficiency was investigated for sampling volumes ranging from 30 to 80 mL, and 70 mL was selected as a suitable sampling volume to achieve satisfactory extraction efficiency. The sampling rate affects not only the extraction efficiency, but also the extraction time. When the sample flows through the extraction tube at a low rate, it requires a long test time. Although the increase in sampling rate reduces the extraction time, it often decreases extraction efficiency. In addition, large sampling rate leads to high pressure in the tube, which in turn reduces the service life of the tube. Therefore, the effect of sampling rate (1.25-2.50 mL/min) on extraction efficiency was investigated, and good extraction efficiency and short test time were achieved when the sampling rate was 2 mL/min. High hydrophobic PAHs have poor solubility in water. An appropriate amount of organic solvent in the sample solution can improve the solubility of PAHs to obtain accurate analytical results. However, the extraction efficiency was affected by the added organic solvent. Thus, the effect of volume fraction of methanol (0, 0.5%, 1%, 2%, 3%, and 5%, v/v) on the extraction efficiency was investigated. The sample solution without methanol afforded better extraction efficiency and satisfactory repeatability. After online extraction, the desorption directly affects the desorption efficiency. The peak areas of the eight PAHs were investigated with different desorption times (0.2, 0.4, 0.6, 0.8, 1.0, and 2.0 min), and a desorption time of 2.0 min was required to fully desorb all analytes and reduce their residuals. The IT-SPME-HPLC-DAD method was established under the optimized conditions, and the limits of detection (LODs), linear equations, linear ranges, and correlation coefficients were obtained. The LODs of the eight PAHs were in the range of 0.001-0.005 μg/L, the quantitative ranges of the analytes were 0.003-15.0 μg/L for Fla and Pyr, 0.010-20.0 μg/L for Phe and Ant, and 0.017-20.0 μg/L for Nap, Acy, Ace and Flu, the enrichment factors were in the range of 2029-2875, and the analytical precision was satisfactory (intra-day RSD%≤4.8%, and inter-day RSD≤8.6%). Compared with some reported methods, the method reported herein provided higher sensitivity, wider linear range, and shorter test time. This method was applied to the detection of PAHs in common drinking water, including bottled mineral water and water from drinking fountain. The satisfactory recovery (76.3%-132.8%) obtained proves that the method is suitable for the determination of trace PAHs in real water samples, with high sensitivity, rapid testing, online detection, and good accuracy. The extraction tube also exhibited satisfactory durability and chemical stability.

The widespread usage of per- and poly-fluoroalkyl substances (PFAS) has caused great concern due to their potential toxicology to human and environmental health. However, there have been limited investigations on the vertical distribution of PFAS in fluorine (F) contaminated soils. In this study, the spatial and vertical distribution of metals, total F, and PFAS in the soil profiles were investigated at different areas in an industrial city. The higher F concentrations in the farmland soils with intensive agricultural activities suggested the impacts of soil tillage. The ΣPFAS concentrations ranged from 0.187 to 1.852 ng g -1 in all soil samples, with PFOA as the dominant pollutant, which accounted for 17.2%-51.6% of the ΣPFAS in all samples. Highest level of PFAS was found in the shallow layer of the soil profiles. The long-chain PFAS such as PFUdA and PFTeDA tended to remain in the topsoil, while the short-chains (PFBA, PFPeA, and PFHxA) have migrated to depth of 100 cm in the vertical soil profile. The application of F-enriched phosphorus fertilizers and atmospheric deposition may be important sources of F and PFAS in soils in this area. Correlation analysis indicated that most of PFAS have similar common sources, and the significantly positive correlation between Zn and PFAS suggested they may share similar sources. This study highlights the need for further work to monitor the PFAS level in soil environments in industrialized areas, in addition to focusing on soil metal and F pollution., (Copyright © 2022 Elsevier Ltd. All rights reserved.)