Antimony Research Articles

Turmeric products: Evaluation of curcumin and trace elements

Turmeric (Curcuma longa L.) is valued for its coloring properties, flavor enhancement, functionality, as well as antioxidant and anti-inflammatory effects, which help prevent various diseases. This study aimed to evaluate the levels of curcumin and trace elements (Cr, Co, Ni, As, Mo, Cd, Sb, Ba, Hg, and Pb) in 30 samples of turmeric capsules. The quantification of curcumin was performed by spectrophotometry, with results ranging from 0.03 g/100 g to 37.6 g/100 g. The concentration of trace elements was determined by ICP-MS after acid digestion of the samples. Except for the elements Sb and Hg, which showed levels below the quantification limits (0.002 and 0.008 mg/kg, respectively), the results were: Cr (<0.008–0.083 mg/kg), Co (<0.003–0.78 mg/kg), Ni (<0.008–1.61 mg/kg), As (<0.003–0.083 mg/kg), Mo (<0.008–1.21 mg/kg), Cd (<0.002–0.076 mg/kg), Ba (<0.008–23.48 mg/kg), and Pb (<0.008–0.619 mg/kg). The interaction between curcumin and the trace elements was complex, with no direct relationship found between them. The estimated daily intake (EDI) of curcumin varied from 0.004 to 2.684 mg/kg of body weight, with 13 samples below 10 % of the acceptable daily intake (ADI), 12 samples between 10 % and 50 % of the ADI, and three samples above 50 %. For trace elements, Co showed the highest contribution, corresponding to 2.72 % of the health-based guidance value established by EFSA. A careful approach in marketing turmeric-based products is fundamental to ensure their quality, efficacy, and safety for consumers.

Genesis of high-grade lode gold shoot dominated by ore fluid overprinting during a ductile-brittle shear event

Lode gold deposits hosted by ductile-brittle shear zones account for more than one-third of the world’s gold production. High-grade ore shoots from this type of deposit are the most critical exploration targets. The ore shoots can form through the post-depositional deformation of auriferous sulfides or overprinting of ore fluids accompanied by coupled dissolution-reprecipitation (CDR) reactions. However, the mechanism that dominates ore shoot genesis remains unknown, primarily due to the controversial single progressive or polyphase nature of ore-bearing shear zones. Here, we report on geological and geochemical analyses we conducted at the large Hetai goldfield, South China, to construct an accurate gold upgrading model for the formation of ore shoots. Stages 1−3 of mineralization at Hetai show features typical of ductile shearing, while Stage 4 is characterized by quartz-sulfide veinlets in brittle fractures. 40Ar/39Ar ages of ca. 184 Ma and 157 Ma for the mineralization of stages 1 and 4 overlap with the regionally dextral ductile-brittle shear that occurred during ca. 210−162 Ma. Thus, the gold event at Hetai should have been controlled by a single progressive ductile-brittle shear episode, rather than polyphase structural events. The auriferous fluids at Hetai precipitated minor invisible gold in pyrites (mean 0.173 ppm) produced during stages 1−4 through fluid-rock interaction. The systematic increase of elements Au, As, Sb, Bi, Ag, and Cu and δ34S values in ductile-deformed pyrites from stages 1−3 indicate that early invisible gold upgrading should be the result of the post-depositional remobilization of auriferous sulfides during the long-lived ductile-brittle transition. Cataclastic pyrites hosting invisible gold from Stage 4 have zoned and porous mantles with elevated invisible gold (mean 0.503 ppm) and Sb, Bi, Pb, Co, Ni, and Ti contents. These pyrites are further replaced by chalcopyrite and pyrrhotite with increasing invisible gold, Co, and Ni contents. In addition, numerous visible native gold grains in Stage 4 are included in sulfides formed by replacement and develop along the microfractures and grain boundaries of these sulfides. We suggest the late invisible and visible gold upgrading events in Stage 4 can be attributed to the auriferous fluid superposition and subsequent replacement of pyrite via CDR reactions in a brittle regime. Therefore, the gold upgrading process at Hetai is jointly caused by the early remobilization induced by ductile-brittle deformation and the late ore fluid superposition with accompanying CDR reactions within a brittle domain. As the ore fluid superposition and CDR reactions in Stage 4 produce a significant amount of visible gold, they exert a first-order control on the genesis of ore shoots at Hetai. The refined model may be widely applicable to lode gold deposits elsewhere and can be used to identify regions with promising exploration targets.

Constraints of in-situ elemental compositions and U–Pb ages of cassiterite on the origin of the Cretaceous Gejiu and Dulong tin deposits, SW China: Implications for the linkage of tin belts in SE Asia

The western Yunnan tin belts in SW China and the southern Myanmar tin belt in SE Asia are traditionally thought to be part of the SE Asian tin metallogenic province. However, the tectonic setting of the Youjiang tin belt in SW China and its genetic relationship to the other tin belts are poorly documented. In this belt, the giant Gejiu and Dulong tin deposits are typical of skarn-type deposits and both contain contact and distal skarn orebodies. Tin ores of distal orebodies in these two deposits are composed of cassiterite, sulfide and calcite. In both deposits, most cassiterite grains from these ores are rich in Fe and W and depleted in Nb and Ta. They have 238U/206Pb ages between 81.4 and 84.1 Ma, similar to hosting granitic plutons. Two generations of cassiterite with distinctly different microtextures and trace elemental compositions can be recognized. The first generation (Cst-I) is compositionally and texturally homogeneous, but the second generation (Cst-II) displays distinctly oscillatory zoning. Cst-II contains Nb, W, and U lower, and Fe, Ta, Zr and chalcophile elements (Ga, Ge, In, and Sb) higher than Cst-I. These textural and compositional variations reflect the potential involvement of meteoric water in the magmatic-hydrothermal system. In this system, ore-forming fluids were evolved to more alkaline and oxidized to facilitate the precipitation of cassiterite. Our study indicates that these two deposits in the Youjiang tin belt have mineralization styles similar to those in the adjacent western Yunnan and southern Myanmar tin belts and all these tin belts belong to the SE Asian metallogenic provinces. A westward-younging trend of tin mineralization in these three belts can be explained by the rollback of the subducted Neo-Tethyan oceanic slab. This setting is different from the one related to the subduction of the Paleo-Pacific plate.

Toxic and essential elements in honeybee venom from Slovakia: Potential health risk to humans

Honeybee venom is one of the natural substances produced by bees (Apis mellifera). Their venom gland produces venom which plays a defensive role. In this study a concentration of macro and trace elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Sb, Se, Sr, Pb and Zn) in foragers′ and honeybees′ venom was analysed by axial inductively coupled plasma optical emission spectrometry (ICP OES) with good validation parameters to differentiate the element accumulation ability in honeybee venom. Cumulative ability for some elements (As, Al, Ba, Cr, Li, Mo, Pb, and Zn) in bee venom was clearly demonstrated. Oppositely, levels of macro elements (Ca, K, Mg and Na) in venom were several times lower compared to the levels detected in foragers. Moreover, PCA analysis of bee samples showed that Cr was associated with locality Košice, and Cd with locality Krompachy; both have rich industrial history. Since some of analysed elements are potentially toxic for humans, a risk assessment for bee-stung scenario was also calculated. A new way of exposure to potentially toxic elements via honeybee stung was showed in this study. Non-carcinogenic risk assessment for humans to selected toxic elements (As, Cd, Cr, Ni, and Pb) demonstrated acceptable risk and moreover the same we may conclude for potential carcinogenic risk for beekeepers exposed to As, Cd, Ni, and Pb via venom over their whole life.

Seasonal changes in the physicochemical characteristics of atmospheric aerosol at the research station “Ice Base Baranova Cape” (Severnaya Zemlya archipelago)

Since 2017 we have carried out aerosol sampling at the research station “Ice Base Baranova Cape” (Novaya Zemlya Archipelago) with the purpose of studying the variations in aerosol physicochemical characteristics: the concentrations of ions, microelements, organic and elemental carbon (ОС and ЕС), as well as the isotopic composition of carbon δ13C in the aerosol. The average summed concentrations of ions throughout the period of measurements were 1,99 μg/m3, the concentrations of elements were 51,1 ng/m3; and those of ОС and ЕС were 398 and 25 ng/m3, respectively; the isotopic composition of carbon δ13C was–27.6 ‰. The main contribution (73 %) to the ion composition of atmospheric aerosol is due to “marine” ions Na+ and Cl-, and the contribution to the elemental composition is due to terrogenic Fe and Al (71 %). The large enrichment coefficients (with respect to Na+ in sea water) were manifested for ions SO 2-, K+, and Ca2+. Aerosol enrichment by these ions is the largest in the warm period. In the aerosol elemental composition, we identified large enrichment coefficients (with respect to Al in the Earth’s crust) in elements Se, Sn, Sb, Mo, As, Zn, Cu, Cr, Pb, and Cd, indicating their technogenic origin. The nearest sources of aerosol enrichment by technogenic elements are plants for mining and processing mineral resources in the Taymyr Autonomous Okrug. The statistical generalization of the multiyear data allowed us to calculate for the first time the annual average behavior of the chemical composition of aerosol in the study region. With respect to the seasonal variations, the ions and elements can be divided into three groups: 1) with winter maximum (Na+, Cl-, Mg2+, Br-; Se, Cd, V, Co, As); 2) with summer (PO 3-, NH +, CH SO3-, F-) or autumn (Al, Ti, Li, Sr, Fe, Zn, Ba, Ni) maximum; 3) with poorly defined or indefinite variations in other ions (NO -, K+, SO 2-, Ca2+) and elements (Cu, Pb, Mo, W, Sn, Cr, Sb, Mn). As most of the other characteristics, the annual behaviors of the ОС and ЕС concentrations are characterized by the general maximum in the winter-spring period. In addition, a second maximum is manifested in the ОС content in the summer-autumn period. The average monthly carbon isotopic composition in the aerosol varies in the range from –28.3 ‰ (February) to –27.3 ‰ (May).

Quantification of evaporative loss of volatile metals from planetary cores and metal-rich planetesimals

The processes responsible for the isotopic compositions and abundances of volatile elements in the early solar system remain highly debated. Orders of magnitude variation of (highly) volatile elements exist between different magmatic iron meteorite groups, but it is unclear to what extent their depletions can be explained by evaporation from metal melts during parent body accretion and/or subsequent break up. To this end, we present 86 new evaporation experiments with the aim of constraining the volatility of most volatile metals from metallic melts. The results confirm the previously proposed important effects of S in metal melt on the volatility of the elements of interest governed by their S-loving or S-phobic behavior. Nominally S-loving elements In, Sn, Te, Pb and Bi are significantly more volatile in Fe melt relative to FeS liquid, whereas nominally S-avoiding elements Ga and Sb are more volatile in FeS liquid relative to Fe melt, at a given pressure and temperature. The newly derived volatility sequences for S-free/poor and S-rich metallic melts were also compared with commonly used volatility models based on condensation temperatures. The results indicate significant differences between the latter, including the much more volatile behavior of Te, relative to Se, in both explored bulk compositions, which are traditionally assumed to be equally volatile. The (minimum) degree of volatile element depletion due to evaporation was quantified using the new experimental results and models. A comparison between the volatile element depletions in magmatic iron meteorites and the predicted depletions appropriate for evaporation from Fe melts shows that the latter depletions can be easily reconciled with (an) evaporation event(s). Altogether, the new data and models will provide an important framework when more accurate and precise estimates of magmatic iron meteorite bulk volatile element contents are available.

Determining the thickness of a thin aluminum sheet using the transmission measurement of X-rays with varying energies: A comparative analysis between calibration curve fitting and artificial neural network approaches

This study proposes an innovative configuration for thickness measurement based on X-ray transmission, intending to improve the precision of measuring thin aluminum sheets. In this configuration, an activation sample containing Zr, Sb, and Ba elements is irradiated by 59.54 keV gamma rays emitted from three 241Am radioactive sources with a total activity of 1.78 GBq. Subsequently, the activation sample emits fluorescent X-rays at energy levels of 15.78 keV (Zr-Kα1,2), 17.67 keV (Zr-Kβ1), 26.36 keV (Sb-Kα1,2), 29.73 keV (Sb-Kβ1), 32.2 keV (Ba-Kα1,2), and 36.38 keV (Ba-Kβ1). These X-rays are collimated into a narrow beam, which then penetrates through an absorbing sample, and is ultimately recorded by a Si(Li) detector. Two different approaches are investigated to determine the thickness of absorbing samples including Calibration Curve Fitting (CCF) and Artificial Neural Network (ANN). The CCF approach requires constructing linear calibration curves for establishing the relationship between lnR (R is the ratio of the peak areas in measurements with and without absorbing sample) and the thickness of the absorbing sample at each X-ray energy level. The sample thickness is then determined by calculating a weighted average of the measured thicknesses associated with all analyzed energy levels. This approach requires in-depth understanding of radiation physics and proficiency in X-ray spectrum analysis. Meanwhile, the ANN approach uses raw spectra obtained by the Si(Li) detector to predict the thickness of aluminum sheets, facilitating analysis without requiring human intervention. The reliability of these approaches is evaluated through experimental measurements on aluminum sheets with thicknesses ranging from 0.064 cm to 1.074 cm. The results indicate that using X-rays with many different energies leads to superior accuracy in thickness measurements compared to using X-rays with a single energy. Besides, both the CCF and ANN approaches yield relative deviations of less than 3% between the predicted and reference thicknesses. It is important to emphasize that the ANN approach represents a promising solution for automated analysis without the intervention of experts.

Microstructure, joining mechanism, mechanical properties and optimization of inactive solder (Sn9Zn) in low temperature ultrasonic soldering of AlN ceramics and 2024Al

With the development of the electronic packaging industry, there is an increased demand for enhanced strength in DBA substrates. Ultrasonic soldering technology allows low-temperature joining of ceramic-metal materials under ambient air conditions. In this paper, we successfully achieved the joining between AlN ceramics and 2024Al using Sn9Zn solder and ultrasonic soldering technique, while also analyzing the joining mechanism through Comsol software simulations. It was observed that under the appropriate ultrasonic amplitude and frequency, the Sn9Zn solder exhibited complete wetting with both base materials, resulting in reliable joints. Building upon this finding, the conventional Sn9Zn solder was further optimized by adding Sb element. The addition of Sb element led to the formation of Zn4Sb3 phase and β-Sn(Sb) phase with Sb acting as solute. Among them, the generation of β-Sn(Sb) solid solution phase effectively improved the joint strength. The maximum joint strength was achieved at an average value of 75.066 MPa when the Sb content reached 1 wt. %. At this point, the failure occurred within the AlN ceramic base material.

Switching Product Selectivity in CO2 Electroreduction via Cu–S Bond Length Variation

Regulating competitive reaction pathways to direct the selectivity of electrochemical CO2 reduction reaction toward a desired product is crucial but remains challenging. Herein, switching product from HCOOH to CO is achieved by incorporating Sb element into the CuS, in which the Cu–S ionic bond is coupled with S–Sb covalent bond through bridging S atoms that elongates the Cu–S bond from 2.24 Å to 2.30 Å. Consequently, CuS with a shorter Cu–S bond exhibited a high selectivity for producing HCOOH, with a maximum Faradaic efficiency (FE) of 72%. Conversely, Cu3SbS4 characterized by an elongated Cu–S bond exhibited the most pronounced production of CO with a maximum FE of 60%. In situ spectroscopy combined with density functional theory calculations revealed that the altered Cu‒S bond length and local coordination environment make the *HCOO binding energy weaker on Cu3SbS4 compared to that on CuS. Notably, a volcano‐shaped correlation between the Cu–S bond length and adsorption strength of *COOH indicates that Cu–S in Cu3SbS4 as double‐active sites facilitates the adsorption of *COOH, and thus results in the high selectivity of Cu3SbS4 toward CO.

Switching Product Selectivity in CO2 Electroreduction via Cu-S Bond Length Variation.

Regulating competitive reaction pathways to direct the selectivity of electrochemical CO2 reduction reaction toward a desired product is crucial but remains challenging. Herein, switching product from HCOOH to CO is achieved by incorporating Sb element into the CuS, in which the Cu-S ionic bond is coupled with S-Sb covalent bond through bridging S atoms that elongates the Cu-S bond from 2.24 Å to 2.30 Å. Consequently, CuS with a shorter Cu-S bond exhibited a high selectivity for producing HCOOH, with a maximum Faradaic efficiency (FE) of 72 %. Conversely, Cu3SbS4 characterized by an elongated Cu-S bond exhibited the most pronounced production of CO with a maximum FE of 60 %. In situ spectroscopy combined with density functional theory calculations revealed that the altered Cu-S bond length and local coordination environment make the *HCOO binding energy weaker on Cu3SbS4 compared to that on CuS. Notably, a volcano-shaped correlation between the Cu-S bond length and adsorption strength of *COOH indicates that Cu-S in Cu3SbS4 as double-active sites facilitates the adsorption of *COOH, and thus results in the high selectivity of Cu3SbS4 toward CO.

A comprehensive investigation of alloying elements on site preferences, elastic properties and electronic structure of Mg17Al12 by first-principles calculations

The effect of elemental doping on the site preference, elastic properties and electronic structure of Mg17Al12 has been systematically investigated by first-principles calculations. And twenty-seven elements (Li, Na, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Sr, Y, Zr, Ag, Cd, In, Sn, Sb, Pb, Bi and La) are considered in this study. The calculations of substitution formation energies indicate that the alkali metal (Li), alkaline earth (Ca, Sr) and rare earth (Sc, Y, La) group elements and Ti, Zr favor to occupy Mg sites, and transition group (Fe, Co, Ni, Cu, Ag, Zn, Cd) elements and Ga, Ge, Sn, Sb prefer to occupy Al site, while Na, K, V, Cr, Mn, In, Pb and Bi are unstable in Mg17Al12 phase. Meanwhile, the results of phonon dispersion curves for the preferentially doped systems show that all doped structures are dynamically stable except for Sr, La and Sn doped systems. The elastic constants indicate that all preferential doping models are mechanically stable, and solute atoms with high bulk modulus lead to an increase in the bulk modulus of Mg17Al12 phase. Simultaneously, the calculated shear modulus/bulk modulus ratio (G/B), Poisson's ratio (v) and Cauchy's pressure (C‾12‐C‾44) indicate that the ductility of doped systems is better than Mg17Al12 alloy. All structures are elastic anisotropic, while the doping of Fe, Co and Ni reduces the degree of anisotropy of Mg17Al12 phase. Furthermore, the electronic structures show a strong hybridization between the p-orbitals of Mg and Al and the d-orbitals of alkaline earth, rare earth and Zr elements, resulting in higher structural stability. Finally, the adsorption behavior of O atom on Mg17Al12(110) surface and the structural stability, lattice constants, and elastic modulus of Mg34Al24-xZnx random solid solution alloys are investigated.

Toxic Elements in Sheep Milk, Whey, and Cheese from the Environmentally Burdened Area in Eastern Slovakia and Health Risk Assessment with Different Scenarios of Their Consumption.

The study aimed to determine the content of 17 elements (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Sb, Se, Sr, and Zn) in samples of sheep milk, cheese, and whey (36 samples in total) collected from a farm in an environmentally burdened area due to the long-term mining and industrial activity in Slovakia as well as to determine the possible risk of consumption via health risk assessment calculations. Consumption of 120 g of milk, 500 g of milk, 20 g of cheese, and 100 g of cheese were used in calculations for children and adults, respectively. According to the results, concentrations of four elements are controversial. Lead concentrations in all types of samples exceeded the maximum permissible lead limit in milk set by European Union legislation. The content of Se and As is problematic for children's consumption, and the target hazard quotient for As and Al is higher than one (considered potentially not safe) in all scenarios. According to the target system approach, lead concentrations in milk and cheese could adversely influence the nervous system and kidneys of adults' and children's developmental and reproductive systems. Considering the worst-case scenario, consuming sheep milk and cheese from the monitored areas could represent a risk and be potentially harmful to human health, mainly for children. However, further monitoring of the levels of elements and concentrations in environmentally burdened areas and more robust data on consumption are needed.

Discrimination of Pb-Zn deposit types using the trace element data of galena based on deep learning

Different types of ore deposits exhibit distinct metal sources, physicochemical conditions, and ore-forming processes. Galena, a key sulfide in Pb-Zn deposits, possesses trace elements that may be utilized for classifying Pb-Zn deposit types. Presently, research on classifying ore deposit types based on trace elements in galena is sparse, and there is a lack of robust methods for distinguishing Pb-Zn deposit types using these trace elements. In this study, we demonstrate that a deep learning algorithm, based on the trace elements in galena, can be effectively utilized for classifying Pb-Zn deposit types. The model training process utilized UMAP for visualization, and the evaluation was conducted using multiple statistical metrics, confusion matrices, and ROC curves. Finally, by dissecting the ’black box’ with the UMAP algorithm, we established a comprehensive set of analysis methods for discriminating deposit types: discrimination-visualization-evaluation-dissection. A dataset comprising 828 LA-ICP-MS analyses of galena from 34 Pb-Zn deposits worldwide was curated from peer-reviewed sources. It includes data on 7 elements (Se, Ag, Cd, Sn, Sb, Tl, and Bi) across 7 deposit types: carbonate replacement deposits (CRD), epithermal, mississippi valley type (MVT), sedimentary exhalative (SEDEX), skarn, volcanogenic massive sulfide (VMS), and vein-type deposits. Initially, we selected the UMAP algorithm from three visualization methods (PCA, t-SNE and UMAP), for its ability to balance global and local structures in visualizing the internals of the deep model. Subsequently, we developed a deep learning model (1D-CNN) for deposit type classification. Various evaluation metrics and visual analyses indicate exceptional performance of our model, achieving an overall accuracy of 99.18 % on the test set. Finally, the SHAP algorithm was used to analyze the importance of trace elements in galena for different deposit types. Elements such as Sn, Tl, and Bi were found to be particularly significant in classifying deposit types, confirming the influence of multiple elements in Pb-Zn deposits within galena. Therefore, we conclude that deep learning algorithms can effectively identify Pb-Zn deposit types, offering new insights into the study of galena.

Integrating waste valorization and symbiotic microorganisms for sustainable bioremediation of metal(loid)-polluted soils

Remediation strategies for metal(loid)-polluted soils vary among the wide range of approaches, including physical, chemical, and biological remediation, or combinations of these. In this study, we assessed the effectiveness of a set of soil remediation treatments based on the combined application of inorganic (marble sludge) and organic amendments (vermicompost, and dry olive residue [DOR] biotransformed by the saprobic fungi Coriolopsis rigida and Coprinellus radians) and inoculation with arbuscular mycorrhizal fungi (AMFs) (Rhizophagus irregularis and Rhizoglomus custos). The treatments were applied under greenhouse conditions to soil residually polluted by potentially toxic elements (PTEs) (Pb, As, Zn, Cu, Cd, and Sb), and wheat was grown in the amended soils to test the effectiveness of the treatments in reducing soil toxicity and improving soil conditions and plant performance. Therefore, we evaluated the influence of the treatments on the main soil properties and microbial activities, as well as on PTE availability and bioaccumulation in wheat plants. Overall, the results showed a positive influence of all treatments on the main soil properties. Treatments consisting of a combination of marble and organic amendments, especially biotransformed DOR amendments, showed the greatest effectiveness in improving the soil biological status, promoting plant growth and survival, and reducing PTE availability and plant uptake. Furthermore, AMF inoculation further enhanced the efficacy of DOR amendments by promoting the immobilization of PTEs in soil and stimulating the phytostabilization mechanisms induced by AMFs, thus playing an important bioprotective role in plants. Therefore, our results highlight that biotransformed DOR may represent an efficient product for use as a soil organic amendment when remediating metal(loid)-polluted soils, and that its application in combination with AMFs may represent a promising sustainable bioremediation strategy for recovering soil functions and reducing toxicity in polluted areas.

Characterization of Metal Elements in Atmospheric Fine Particulate Matter and Their Sources in Winter in the Southern Sichuan Urban Agglomeration

To investigate the concentration characteristics and sources of metal elements in PM2.5 during winter heavy pollution in the southern Sichuan urban agglomeration (Zigong, Luzhou, Neijiang, and Yibin), the metal elements in PM2.5 were measured using membrane sampling methods from December 30, 2018 to January 14, 2019, and the enrichment factor method (EF) and positive matrix factorization(PMF) were applied to investigate the sources of metal elements. The metal element observation data of Zigong in the same period of 2015 were also used to investigate the changes in metal element pollution and enrichment in Zigong in the middle and end of the implementation of China's Air Pollution Prevention and Control Action Plan. The main findings were as follows:① The concentrations and percentages of metal elements in particulate matter in different cities did not differ significantly. The elements with higher concentrations in the four cities showed similarities, with Al, Sb, and Fe at the top. From the comparison of different observation periods in Zigong, the concentrations of all elements except Tl changed. ② The results of the enrichment factor calculation showed that the enrichment of the elements Cr (Zigong and Yibin), Ni, Cu, As, Se, Ag, Cd, Sb, Tl, and Pb in the urban agglomeration was high. The comparison of the enrichment levels of elements in Zigong for different observation periods showed that the enrichment levels of all elements, except Cu, tended to decrease in the winter observation period of 2018. ③ The results of PMF source analysis showed that the metal elements in each city mainly originated from dust sources, coal-fired sources, industrial sources, and traffic sources, whereas there was a mixed contribution among the sources. The contribution of the main sources differed among cities, in which Zigong was dominated by traffic dust sources and mixed sources, Luzhou was dominated by industrial sources, Neijiang had a similar contribution from different sources, and Yibin was dominated by traffic sources.

Morphology, physical, and structural aspects of copper nanoparticles induced- metal phosphate nanocompounds for gamma ray shielding and magnetic sensing applications

The inorganic nanocompounds were synthesized by solid state reaction with the composition 10Li2O+(30-x)Sb2O3 + xZnO + 59.5P2O5 + 0.5Cu (in mol%). SEM morphographs of the samples confirmed the grain size ≈0.5–2.5 μm. The EDAX spectra of the samples confirmed presence of copper (Cu) nanoparticles (<2 wt%) in the composition. The EDAX studies showed energy dispersion of Kα- photons by reactivity of elements P, Cu, and Zn, while the element Sb has shown dispersion of Lα- photons up to 10 keV. Mass attenuation coefficient (MAC) has exhibited a few discontinuities (bumps) at low energies (<10 keV) due to K, L- absorption edges of various elements (such as P, Cu, Zn, and Sb) presented in the samples. The shrinking of Phosphorous-Phosphorous separation (dP-P) from 4.716 Ao to 3.990 Ao indicated the greater solidity (or density) of the prepared nanocompounds at higher content of ZnO. XRD spectra showed the presence of major crystallites such as LiPO3, Li3PO4, Li6P6018, SbPO4, Cu3PO4, Cu2P2O7, Cu3[PO4]2, Zn[PO3]2, Zn2P2O7, ZnP4O11, and LiZnPO4 in the prepared nanocompounds. The average crystallite size was determined in the range of 35–83 nm. FTIR spectra of these compounds displayed the [PO2]−, [PO3]−, [PO4]3−, and [ZnO4] units along with linkages P─O─P, O─P─O, Sb─O─Sb, Cu─O─Cu, etc. A band due to vibrations of Cu─O bond has been observed in the range of 466–478 cm−1, which endorses the contribution of copper nanoparticles in the solid state reaction of the metal phosphate nanocompounds. A partially resolved hyperfine structure of magnetic resonance signals corresponding to g|| ≈2.4 and g⊥ ≈2.05 were observed due to the presence of an anisotropic hyperfine interaction of the electron spin (S = 1/2) with the nuclear spin (I = 3/2) of copper isotopes (63Cu and 65Cu) in the samples.

Application of handheld/portable spectroscopic tools to the identification, inner stratigraphy and mapping of archaeological metal artefacts

Field handheld/portable instrumentations, such as in-situ geochemical analyzers, have the potential to assist efficiently targeted geochemical archaeometry campaigns in detecting and quantifying specific elements. Non-destructive portable energy dispersive x-ray fluorescence and micro-destructive handheld laser-induced breakdown spectroscopy (LIBS) instrumentation were utilized to investigate the elemental composition, internal stratigraphy by depth profiling and microscale compositional mapping of five copper and two iron alloy artefacts collected from various ancient graves in the Minervino Murge area, Apulia, Italy. The primary elements identified by both techniques included Cu, Sn and Pb in copper alloys, and Fe with minor amounts of Cu and Pb in iron alloys. Furthermore, the elements Al, Ca, Si, Mg, Na and K, mostly originated from soil contamination, and the trace elements Sb, Ni and Zn were detected. The satisfactory performance of both techniques was assessed by their capacity to provide reproducible elemental composition data. Finally, the depth profile and mapping achieved by LIBS contributed to understanding the metal processing and history of the objects studied, so confirming both techniques to be robust analytical tools in outdoor archaeology and archaeometry campaigns.

Exploration Vectors and Indicators Extracted by Factor Analysis and Association Rule Algorithms at the Lintan Carlin-Type Gold Deposit, Youjiang Basin, China

The Youjiang Basin in China is the world’s second-largest concentrated area of Carlin-type Au deposits after Nevada, USA, boasting cumulative Au reserves nearing 1000 t. This study examined the recently unearthed Lintan Carlin-type Au deposit within the Youjiang Basin. Factor analysis and association rule algorithms were used to identify exploration vectors and indicators essential for navigating this promising geological territory. In the Lintan mining area, the geological strata encompass the Triassic Bianyang, Niluo, and Xuman formations comprised clastic rocks, followed by the deeper Permian Wujiaping Formation with massive carbonate rocks. The orebodies are restricted to the F14 inverse fault, cutting through the Xuman Formation, with an additional F7 fault between the Wujiaping and Xuman formations. A total of 125 rock samples from the F14 fault and a representative cross-section were analyzed for 15 elements (Au, Ag, As, Bi, Cd, Co, Cu, Hg, Mo, Ni, Pb, Sb, Tl, W, and Zn). The elements were divided into four groups based on cluster and factor analysis. Group 1 (Co, Cu, Zn, Ni, Tl, W, and Bi) was mainly enriched in the Xuman, Niluo, and Bianyang formations controlled by sedimentary diagenesis. Group 2 (Au, As, Hg, and Sb) was concentrated in the F14 and F7 faults, representing Au mineralization. Group 3 (Pb, Ag, and Mo) was mostly enriched near the F14 and F7 faults, displaying a peripheral halo of Au mineralization, and was probability controlled by ore-forming hydrothermal activities. Group 4 (Cd and Mo) exhibited extreme enrichment along the periphery of the F7 fault. This pattern indicates the presence of a substantial hydrothermal alteration zone surrounding the fault, likely influenced by ore-forming hydrothermal processes. Additionally, Pb, Ag, Cd, Mo, and W are considered essential indicators for ore formation besides Au, As, Sb, Hg, and Tl. Twelve effective association rules were derived using the association rule algorithm, which can aid in discriminating Au mineralization. The spatial distributions of the 15 elements indicated that the F14 fault is the main ore-bearing fracture zone, while the F7 fault serves as the ore-conducting structure, channeling ore-forming fluids into the F14 fault. Faults between the Wujiaping and Xuman formations, along with their associated reverse faults, present potential prospecting targets both within and outside the Lintan Au deposit in the Youjiang Basin. Exploration geochemical data can be fully utilized by combining factor analysis and association rule algorithms, offering key guidance for prospecting Carlin-type gold and similar deposits.

Experimental study for inorganic and organic profiling of toy makeup products: Estimating the potential threat to child health

Inorganic elements are added to toys as impurities to give desired stability, brightness, flexibility, and color; however, these elements may cause numerous health issues after acute or chronic exposure. In this study, the inorganic profile of 14 elements (Al, As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Ni, Se, Sb, Pb, and Zn) in 63 toy makeup products was identified by inductively coupled plasma-mass spectrometry after microwave acid digestion method. Additionally, organic allergen fragrance was investigated by gas chromatography-mass spectrometry. The systemic exposure dosage (SED), margin of safety (MoS), lifetime cancer risk (LCR), hazard quotient (HQ), and hazard indices were used to assess the safety evaluation. Then, 57 out of 63 samples (90.48%) exceeded the limits at least for one toxic element with descending order Ni > Cr > Co > Pb > Sb > Cd > As > Hg. The SED values were compared with tolerable daily intake values and remarkably differences were found for Al and Pb. The MoS values for 57.15% of samples exceeded the limit value for Al, As, Cd, Co, Hg, Mn, Sb, and Zn elements. The LCR values were observed at 100% (n = 63), 79.37% (n = 50), 85.71% (n = 54), 77.78% (n = 49), and 18.87% (n = 10) for Cr, Ni, As, Pb, and Cd, respectively. Also, the skin sensitization risks were obtained for Cr and Ni at 26.980% (n = 17) and 9.52% (n = 6), respectively. The HQ values for 80% of samples were found to be ≥ 1 at least for one parameter. The investigation of fragrance allergens in samples did not show any significant ingredients. As a result, toy makeup products marketed in local stores were found to be predominantly unsafe. Children should be protected from harmful chemicals by regular monitoring and strict measures.

Effects of Sb on the properties and interfacial evolution of SAC305-2Bi-xSb/Cu solder joints

This study investigated the influence of Sb addition on the microstructure, thermal behavior, mechanical properties, and interfacial evolution of SAC305-2Bi-xSb/Cu solder joints. Compared with the SAC305-2Bi alloy, the melting temperature and pasty range slightly increased with the increasing of Sb content from 0.2 to 2.0 wt.%, while the undercooling temperature decreased. The research revealed that with the addition of Sb element, the grain size of β-Sn is refined. When the content of Sb is 0.5 wt.%, the grain size of β-Sn reached minimum (19.91 μm). Compared to the SAC305-2Bi alloy, the ultimate tensile strength of SAC305-2Bi–2Sb alloy is increased by 30.10%, contributed to the Sb solid solution strengthening effect and the refinement of β-Sn. With the addition of Sb, the thickness and growth rate of the interface is reduced gradually. The uniform solution of Sb and Sn can significantly inhibit the diffusion rate of Cu atoms and Sn atoms at the interface. The SAC305-2Bi-xSb alloy system has low melting temperature, superior mechanical properties, and reliable solder joints for service. Therefore, it is a potentially reliable lead-free solder for high-stability connections in automotive electronics, communications electronics, and medical devices.