•Inorganic fluorine was the main form of tea fluorine, and most EOF in tea were still unknown.•PFCs residues in tea were mainly short-chain, and PFOA could be an indicator chemical for tea PFCs.•Less fermented teas contained significantly higher PFCs than more fermented teas (p < 0.01).•The highest TF content found in tea samples poses risk of fluorosis.•PFCs residues in tea samples caused no immediate harm.To explore the residual characteristics of fluorine and perfluorinated compounds (PFCs) in tea, the total fluorine (TF), extractable organofluorine (EOF) and PFCs in 19 Chinese commercial teas of five categories were measured using cyclic neutron activation analysis combined with HPLC-MS/MS. The results showed that fluorine mainly existed as inorganic fluorine in teas, and identified fluorine (∑PFCs quantified as F) only accounted for 0.023–0.41% of EOF, indicating that most EOF in tea were still unknown. 50–99% of ∑PFCs in tea were short-chain (C ⩽ 6), while perfluorooctanoic acid was the typical PFCs residual species. Less fermented teas contained significantly higher PFCs (mean, 20 ng/g) than more fermented teas (3.0 ng/g, p < 0.01), suggesting that microbe may degrade PFCs during fermentation. The highest TF content was discovered in Hubei brick tea, which poses risk of fluorosis, whereas PFCs residues in teas caused no immediate harm.

Carbon nanotubes (CNTs) and graphene, and materials based on these, are largely used in multidisciplinary fields. Many techniques have been put forward to synthesize them. Among all kinds of approaches, the low-temperature plasma approach is widely used due to its numerous advantages, such as highly distributed active species, reduced energy requirements, enhanced catalyst activation, shortened operation time and decreased environmental pollution. This tutorial review focuses on the recent development of plasma synthesis of CNTs and graphene based materials and their electrochemical application in fuel cells.

The selective extraction of minor actinides(III) from the lanthanides(III) is a key step for spent fuel reprocessing. Theoretical calculations of geometries, electronic structures, coordination complexion, and thermodynamic properties of the actinides are essential for understanding the separation mechanisms and relevant reactions. This article presents a critical review of theoretical studies on actinide systems involved in the An(III)/Ln(III) separation process. We summarize various theoretical methods for electronic and molecular scale modeling and simulations of actinide coordination systems. The complexing mechanisms between metal cations and organic ligands and the strategies for the design of novel ligands for separation are discussed as well.Highlights► We review recent advances in computational modeling and simulations on the An(III)/Ln(III) separation process. ► Various theoretical methods for electronic and molecular-scale modeling and simulations of actinide systems are summarized. ► The complexation between soft-donating ligands and An(III)/Ln(III) ions are explored. ► The strategies for design of novel organic ligands for separation are discussed.

Cyclic neutron activation analysis method was conducted for determination of Se in food samples. High accuracy and good precision were proved by analyzing certified reference materials (CRMs) of chicken (GBW10018), rice (GBW10010) and cabbage (GBW10014). The detection limits for the three CRMs reached 0.16, 0.66 and 1.2 ng after 6 cycles at the 161.9 keV γ-peak from 77mSe, under a neutron flux of 9.0 × 1011 n cm−2 s−1 and the conditions of 30 s irradiation, 2 s decay, 30 s counting and 2 s waiting, significantly lower than those of conventional neutron activation analysis without any cycles, which were 0.94, 3.6 and 4.3 ng, respectively.

With the rapid development of nanosciences and nanotechnology, a wide variety of manufactured nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and industries. While nanomaterials possess more novel and unique physicochemical properties than bulk materials, they also have an unpredictable impact on human health. In the pharmacology and toxicology studies of nanomaterials, it is essential to know the basic behavior in vivo, i.e. absorption, distribution, metabolism, and excretion (ADME) of these newly designed materials. Radiotracer techniques are especially well suited to such studies and have got the chance to demonstrate their enchantment. In this paper, radiolabeling methods for carbon nanomaterials, metallic and metal oxide nanoparticles, etc. are summarized and the applications of the radiolabeled nanomaterials in pharmacology and toxicology studies are outlined.

The toxicity of carbon nanotubes is the subject of ongoing debate. A preliminary study using a small number of mice shows that they may be safe, but the results should be treated with caution.

To investigate the toxicological effects of nanomaterials, experimental studies on the absorption and accumulation in organisms are of broad interest. In the present study, Caenorhabditis elegans (C. elegans) was used as a “model” organism to investigate the bioaccumulation and toxicological effects of engineered copper nanoparticles with a scanning technique of microbeam synchrotron radiation X-ray fluorescence (μ-SRXRF). The adult hermaphrodite is anatomically simple with 959 somatic cells and 1 mm in length. The mapping results of the whole organism indicate that the exposure to copper nanoparticles can result in an obvious elevation of Cu and K levels, and a change of bio-distribution of Cu in nematodes. Accumulation of Cu occurs in the head and at a location 1/3 of the way up the body from the tail compared to the un-exposed control. In contrast, a higher amount of Cu was detected in other portion of worm body, especially in its excretory cells and intestine when exposed to Cu2+. The results compared well with total Cu levels in nematodes, which were 4.10 ± 0.54, 12.32 ± 0.49 and 5.22 ± 0.63 μg g−1 dry weight for the PBS, Cu2+ and Cu nanoparticle groups, respectively, measured by ICP-MS. The nondestructive and multi-elemental μ-SRXRF provides an important tool for mapping the elemental distribution in the whole body of a single tiny nematode at lower levels.

AbstractPassive air samplers (polyurethane foam disks) were deployed at 25 urban sites and 66 rural sites over the period of July to October 2005, partly between October 2005 and January 2006 for about 120 days across China, and analyzed for extractable organo-chlorine /-bromine /-iodine (EOCl/EOBr/EOI) and polychlorinated biphenyls (PCBs) using hybrid neutron activation analysis (NAA) combined with gas chromatographymass spectrometry (GC-MS). The average concentration of EOCl, EOBr, EOI and ΣPCBs among all the sites were 173.7, 3.5, 1.0 and 0.74 ng/d, respectively. Higher values of EOCl/Br/I and PCBs were detected in the areas of high usage and high emission, which were linked to relatively high-income areas in China, while lower in the west ill-developed region of China, which indicated that these pollutants mainly came from industrial pollution. Higher EOCl contents in traffic areas stated that the exhaust emission from vehicle was another main source of organochlorines in the air. The relative proportions of the known organochlorines (84 PCB congeners) to total EOCl were 0.02–3.0%, which implied that most of EOCl measured in air were unknown.

The information on the chemical speciation of trace elements in biological and environmental systems is much needed to evaluate their biological and environmental significance. Albeit a number of atomic behavior-based analytical techniques are available for the analysis of chemical speciation of trace elements, nuclear analytical techniques, especially the molecular activation analysis method, can in many cases play a unique role. This review describes the methodology, merits and limitations of nuclear analytical techniques for chemical speciation study in biological and environmental samples. The emphases are focused on the chemical species and the environmental and biological significance of rare earth elements in natural plants and human liver, selenium in a mammalian organism, mercury in rat brain and liver, chromium in rat organs and Cr-rich yeast, organohalogens in pine needles and marine organisms, and iodine in sea-water, soil, atmosphere, marine plants and the thyroid gland for demonstration of the features of nuclear analytical techniques. The future perspectives of nuclear analytical techniques for the study of chemical species of trace elements will be briefly outlined as well.

To investigate the influence of selenium on mercury phytotoxicity, the levels of selenium and mercury were analyzed with inductively coupled plasma-mass spectrometry (ICP-MS) in garlic tissues upon exposure to different dosages of inorganic mercury (Hg2+) and selenite (SeO32−) or selenate (SeO42−). The distributions of selenium and mercury were examined with micro-synchrotron radiation X-ray fluorescence (μ-SRXRF), and the mercury speciation was investigated with micro-X-ray absorption near edge structure (μ-XANES). The results show that Se at higher exposure levels (>1 mg/L of SeO32− or SeO42−) would significantly inhibit the absorption and transportation of Hg when Hg2+ levels are higher than 1 mg/L in culture media. SeO32− and SeO42− were found to be equally effective in reducing Hg accumulation in garlic. The inhibition of Hg uptake by Se correlates well with the influence of Se on Hg phytotoxicity as indicated by the growth inhibition factor. Elemental imaging using μ-SRXRF also shows that Se could inhibit the accumulation and translocation of Hg in garlic. μ-XANES analysis shows that Hg is mainly present in the forms of Hg–S bonding as Hg(GSH)2 and Hg(Met)2. Se exposure elicited decrease of Hg–S bonding in the form of Hg(GSH)2, together with Se-mediated alteration of Hg absorption, transportation and accumulation, may account for attenuated Hg phytotoxicity by Se in garlic.Highlights► Hg phytotoxicity can be mitigated by Se supplement in garlic growth. ► Se can inhibit the accumulation and transportation of Hg in garlic tissues. ► Localization and speciation of Hg in garlic can be modified by Se.

Carbon nanotubes (CNTs) and graphene, and materials based on these, are largely used in multidisciplinary fields. Many techniques have been put forward to synthesize them. Among all kinds of approaches, the low-temperature plasma approach is widely used due to its numerous advantages, such as highly distributed active species, reduced energy requirements, enhanced catalyst activation, shortened operation time and decreased environmental pollution. This tutorial review focuses on the recent development of plasma synthesis of CNTs and graphene based materials and their electrochemical application in fuel cells.

To investigate the toxicological effects of nanomaterials, experimental studies on the absorption and accumulation in organisms are of broad interest. In the present study, Caenorhabditis elegans (C. elegans) was used as a “model” organism to investigate the bioaccumulation and toxicological effects of engineered copper nanoparticles with a scanning technique of microbeam synchrotron radiation X-ray fluorescence (μ-SRXRF). The adult hermaphrodite is anatomically simple with 959 somatic cells and 1 mm in length. The mapping results of the whole organism indicate that the exposure to copper nanoparticles can result in an obvious elevation of Cu and K levels, and a change of bio-distribution of Cu in nematodes. Accumulation of Cu occurs in the head and at a location 1/3 of the way up the body from the tail compared to the un-exposed control. In contrast, a higher amount of Cu was detected in other portion of worm body, especially in its excretory cells and intestine when exposed to Cu2+. The results compared well with total Cu levels in nematodes, which were 4.10 ± 0.54, 12.32 ± 0.49 and 5.22 ± 0.63 μg g−1 dry weight for the PBS, Cu2+ and Cu nanoparticle groups, respectively, measured by ICP-MS. The nondestructive and multi-elemental μ-SRXRF provides an important tool for mapping the elemental distribution in the whole body of a single tiny nematode at lower levels.