Elemental Chemical Composition Research Articles

Physical and chemical properties, elemental and material snow composition in Rostov-on-Don

To study the current distribution of the heavy metals (HM) levels and iron in the atmospheric precipitation in Rostov-on-Don, an expedition was conducted aimed at simultaneous river water and snow sampling in the Don River, the roadside and park areas. The pH values of the melt-water were characterized by a slightly acidic reaction, and the stale snow in the park had lower values in comparison with the fresh snow. The river water was slightly alkaline, and the concentrations of dissolved migration forms of Pb, Cd, Zn, Ni, Cr, Mn, and Fe did not exceed the MPC. The exception was the Cu content, which exceeded the MPC by 2.4 times. The contents of the dissolved migration forms of Pb, Cd, Zn, Cu, Ni, and Fe in snow exceeded their contents in river waters. The HM and Fe percentage in suspended form in river water and different snow states is calculated and the sequence series are constructed. The analysis showed that in melt-water, in comparison with river water, there is a higher percentage of the HM and iron in the solution. That may be due to the slightly acidic reaction of the snow water medium, which, as is known, promotes the HM and Fe mobilization from the suspension and their transition to the dissolved state. Using electron microscopy and X-ray phase analysis, the suspension composition in the snow of the park zone was studied, which is mainly represented by aggregates of clay minerals, quartz grains, water silicates, feldspars, and organic matter clumps.

Structural and mechanical properties of Ta-based coatings deposited on polymers for biomedical applications

The polypropylene meshes currently used for hernioplasty induce severe chronic inflammatory reactions over a long-term period of use. These processes lead to scarring and have a negative effect on the connective tissue and the abdominal walls. It is well-known that the biocompatibility of polymer surfaces might be improved by surface modification. We report on the structure and composition of nanostructured Ta, Ta2O5 and TaON coatings deposited on polypropylene in correlation with their mechanical properties. The elemental distribution and chemical composition of the coatings were analyzed by energy dispersive X-ray spectroscopy. The coatings cross-sectional structure and morphology were observed by electron scanning microscopy. Mechanical tests were performed of the polypropylene and of the samples with Ta-based coatings to evaluate the Vickers hardness and the elastic modulus. The coated samples exhibited higher nano-hardness and elasticity values, significantly exceeding the values of untreated polypropylene samples. The Ta-based coatings deposited by magnetron sputtering improve the mechanical characteristics and biocompatibility of the polypropylene materials in view of, e.g., hernia repair.

Variation of macroand trace elements in organs of the blue honeysuckle subspecies of various environmental and geographic provenance when grown in the Near-Ob foreststeppe (West Siberia, Russia)

The variation limits and organ distribution of macroand trace elements were determined in plants of the three subspecies of Lonicera caerulea L. The leaves, as compared with the stems, were found to accumulate more of B, Са, Mg, Mo, P and Sr and less of Al, Mn, Ti and Zn. The plants of different subspecies, grown on soils of the similar chemical element composition, showed statistically significant differences in contents and organ distribution patterns of Al, Cr, Cu, Fe, Mg, Mo, Na, Ni, Pb, Si, Ti and Zn. The stems of the subspecies of the Far East provenance (L. сaerulea subsp. kamtschatica and L. сaerulea subsp. venulosa) had abnormally high contents of Al, Cr, Fe, Na, Si and Ti.

Effect of sizing agent on interfacial properties of carbon fiber-reinforced PMMA composite

The surface treatment of carbon fibers (CFs) was carried out using a self-synthesized sizing agent. The effects of sizing agent on the surface of CFs and the interface properties of CF/polymethyl methacrylate (PMMA) composites were mainly studied. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and static contact angle were used to compare and study the CFs before and after the surface treatment, including surface morphology, surface chemical element composition, and wettability of the surface. The influence of sizing agent on the mechanical properties of CF/PMMA resin composite interface was investigated. The results show that after sizing treatment, the CF surface O/C value increased by 35.1% and the contact angles of CF and resin decreased by 16.2%. The interfacial shear strength and interlayer shear strength increased by 12.6%.

The effect of soil properties and climate on phytocoenoses biodiversity in the forest-steppe zone of West Siberia

The effect of weather conditions and such soil properties as pH, salt content, as well as different forms of macroand trace elements, on phytocoenoses biodiversity and chemical element contents in the aboveground phytomass was investigated in the forest-steppe zone of the West Siberian plain. Soil chemical element composition and salinity content were found to affect the phytomass content of N, P, K, Na, Ca, Mg, Fe, Mn, Zn, Cu, Sr, Li.

Research into phosphate mineral composition and waste phosphorite ore

Purpose. Theoretical and experimental studies of chemical and mineral composition and the structure peculiarities of phosphorites from Ukrainian deposits to define the degree of their suitability for other industries. Methods. The ore chemical composition was determined by conventional (wet) analysis using standard certified chemical reagents. The mineral composition was studied on the scanning electron microscope equipped with the attachment for the energy-dispersive electron microprobe analysis (EMPA) with the software for calculating the chemical composition of the studied sample microvolume. The petrographic analysis was carried out by the traditional methods of microscopic section preparation with subsequent identification and description of the minerals. The microscopic study of the original ore samples aimed at their mineral composition determination was conducted on the Nu optical microscope (Germany) both in transmitted and reflected light. The thin and polished sections prepared using the standard technology were used as samples. In the laboratory environment, the phosphorites were subjected to magnetic dressing in magnetic fields with different intensity. The experiments in the weak field were modelled with the help of the magnetic analyzer while the experiments in the strong magnetic field were modelled on the rotor separator. The flotation dressing method was studied on the laboratory mechanical flotation machine. Findings. It was found that phosphate nodules are rounded mineral formations of irregular shape; they consist of sand bound with the yellow-brown phosphate cement. Ore useful substance is a phosphorus-bearing mineral that by the element chemical composition corresponds to fluorocarbon-hydroxyl-apatite with the dominant content of Ca (45.23%), P (15.67%), and B (27.87%). The results of the integrated petrographic study of the phosphorite samples from the ore body of “Peremoha” area are presented. Originality.The study has revealed that phosphorus-containing substance in the phosphorite samples is the mass that cements barren minerals (mainly quartz, glauconite, calcite and plagioclase). Practical implications. According to the phosphate content level, the phosphorites from Malokamyshevatske, Iziumske and Sinichino-Yaremovske deposits can be treated as minerals for ferrophosphorus smelting. Keywords: ferrophosphorus, ore substance, phosphorite, mineral varieties, petrography, apatite

Paleogeografía del canal y delta del Dique, Colombia

En la corta historia geológica y geomorfológica de la llanura de inundación, canal y delta del Dique, localizada en la costa Caribe colombiana, se han presentado, en los últimos 500 años, notables cambios por procesos naturales y antrópicos que han modificado la geometría del canal y la morfología del delta, que han repercutido notablemente en la alta sedimentación de las bahías de Barbacoas y de Cartagena en el mar Caribe colombiano, pasando de una bahía a un delta, lo que ha causado problemas ambientales. En este artículo se presenta una reconstrucción de la paleogeografía y sedimentología del canal y delta del Dique a partir de elementos químicos que evidencian la presencia del mar en la zona continental. Se utilizaron métodos de análisis de documentos, mapas históricos, procesamiento e interpretación digital de imágenes de satélite, exploraciones directas del subsuelo, levantamientos geológicos y geomorfológicos detallados de campo, muestreo y análisis geoquímicos de sedimentos y rocas por métodos de fluorescencia de rayos X.

Forensic characteristics of damages to different types of fabrics (materials of clothing), which are formed due to the effect of electric shock devices

Annotation. The article describes the results of a study of experimentally caused damage to various types of non-biological material (simulators of clothing fabrics) under the action of different models of electroshock devices. Particularly, the morphological features of the damages and the elemental chemical composition in the areas of damages are established. In the study, 120 experimental objects were investigated – damage to four types of clothing fabrics (imitators of clothing fabrics – cotton knitwear, linen, synthetic fabrics) caused by the action of three models of electric shock devices. Applied research methods: visual examination (including via optical devices), morphometric, photographic, X-ray fluorescent spectral analysis, statistical. The research results are processed by standard methods of variation statistics. The purpose of the study is to establish the forensic diagnostic criteria for assessing damage to various fabrics (materials) of clothing, causing by the action of electric shock devices. In the course of the experiment, certain morphological features of damage were established, which are formed as a result of the action of electroshock devices on various types of materials (imitators of clothing fabrics). The results of the study indicate that the design features of electro-shock devices are reflected in the morphological pattern of damages on the tissues of clothing, namely, in the nature of the mutual arrangement of injuries, the distance between them, which can be used in forensic practice, as a sign indicating the action of an electroshock device specific model. When carrying out X-ray fluorescence spectral analysis from areas of material damage (simulators of clothing fabrics), metal deposits were found, which, in terms of their elemental composition, corresponded to the chemical composition of the contact electrodes of electroshock devices that caused damage. This regularity can be used as an objective sign of establishing the fact of the action of an electroshock device with a certain elemental composition of the metal of the contact electrodes.

Antibacterial Collagen Composite Membranes Containing Minocycline.

Collagen membranes have been used as bioresorbable barrier membranes in guided tissue/bone regeneration. However, the collagen membranes currently used in clinics lack an active antibacterial function, although infection at surgical sites presents a realistic challenge for guided tissue/bone regeneration. In this study, we successfully prepared novel and advanced collagen composite membranes from collagen and complexes of heparin and chelates of minocycline and Ca2+ ions. These membranes were characterized for chemical structures, morphology, elemental compositions and tensile strength. Invitro release studies were conducted to evaluate the release kinetics of minocycline from these membranes. Agar disk diffusion assays were used to assess their sustained antibacterial capability against model pathogenic bacteria Staphylococcus aureus. The chemical and physical characterization confirmed the successful synthesis of minocycline-loaded collagen composite membranes, namely NCCM-1 and NCCM-2. Both membranes had weaker tensile strength as compared with commercial collagen membranes. They achieved sustained release of minocycline for at least 4 weeks in simulated body fluid (pH 7.4) at 37°C. Moreover, both membranes demonstrated potent sustained antibacterial effects against Staphylococcus aureus. These results suggested that the advanced collagen composite membranes containing minocycline can be exploited as novel guided tissue regeneration membranes or wound dressing by providing additional antibacterial functions.

Origin of Metallic Nature of Na3N.

Among inorganic clathrates, the inner cavity space rarely affects the electronic structure of the framework. We report that the anti-ReO3-type compound Na3N has a metallic nature irrespective of the stoichiometric chemical composition of simple representative elements and that this unusual nature originates from the collapse of the bandgap owing to the presence of a crystallographic cavity. We synthesized Na3N by the plasma-assisted nitridation of alkali metals, and diffuse reflectance measurements indicated a metallic nature. The introduction of nitrogen into the Na metal induced the formation of both the Na+ ion and the crystallographic cavity. The former increased the density of the lattice of Na+ ions to form a wide Na 3s conduction band. The latter interacted with the Na 3s band to enhance the bandwidth, resulting in the collapse of the bandgap. Na3N is a unique nitride, which possesses an electronically active cavity space.

Synthesis of Ag2O–KNbO3 heterojunction photocatalysts with enhanced visible-light-responsive photocatalytic performance for sulfamethoxazole degradation

In this work, Ag2O–KNbO3 composites were fabricated successfully by an in-situ deposition method. The as-prepared 0.15Ag–Nb composite exhibited extremely improved photocatalytic activity for Sulfamethoxazole (SMZ) degradation under the irradiation of visible light compared to the corresponding pure KNO and Ag2O. The apparent rate constant k is 0.0603 min−1, which was 40 and 8 times as that of KNO and Ag2O, respectively. X-Ray diffractometer, transmission (or high resolution) electron microscope, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, photocurrent, Electrochemical impedance spectroscopy and UV absorption spectrum are applied to investigate the crystal structure, morphology, chemical elements composition and states and optical property of the fabricated composites, respectively. Moreover, the degradation pathways of SMZ by 0.15Ag–Nb composite were deduced. The formation of Type Ⅰ heterojunctions between KNO and Ag2O greatly increased the separation of photo-induced holes and electrons, thus induced to the improved photocatalytic property of the as-prepared 0.15Ag–Nb composite.

Indian mustard bioproducts dry-purification with natural adsorbents - A biorefinery for a green circular economy

Processes based on homogeneous catalysts are the most widely used for industrial production of fatty acid derivatives, despite catalyst loss in aqueous effluents during the wet-purification stage. In this work, dry-purification of the crude bioproducts; ethyl biodiesel and biolubricants, derived from Indian mustard was conducted using various natural mineral (clay) and organic (plant issue) adsorbents to evaluate operating conditions including temperature, contact time and number of treatment cycles and to define the optimal procedure. Adsorbent characterization was determined by average particle size assessed using laser granulometry, morphology and elemental chemical composition measured by scanning electron spectroscopy with microanalysis using energy dispersive X-ray spectroscopy, chemical structure determination based on Fourier Transform InfraRed spectroscopy and porosity and specific area assessed using carbon dioxide or nitrogen adsorption. The quality of the biofuel and biolubricants, before and after dry-purification on the above adsorbents, was evaluated using different methods including Karl Fischer titration, gas chromatography with a flame ionization detector and inductively coupled plasma-atomic emission spectroscopy. Montmorillonite clay and finely ground Indian mustard stems (particle size of 100–710 μm) without further pyrolysis or carbonization treatment were found to be the best adsorbents. Combined with the selected dry-purification procedure (35–45 °C, 20 min, single treatment cycle), most impurities including residual glycerides, free glycerin, water, catalysts and metals were removed from the resultant ethyl biodiesel thus meeting the basic biofuel specifications of acid value, color, density, viscosity, flash point, pour point, cloud point, cold filter plugging point, higher heating value, and oxidation stability. Further purification of biolubricants was required using bubble-washing with citric acid and vacuum distillation to obtain a product with acceptable density, viscosity and color. This work highlights the potential of a biorefinery system focused on Indian mustard contributing to a green circular economy, that would benefit both farmers and consumers in the respect of environment; farmers would gain in energy security and flexibility by biofuel, biolubricant and other bioproducts on-farm production, while ensuring healthy food security and offering job opportunities, the whole with reduced chemical and energy inputs and minimized waste effluents.

Petrographic and geochemical characteristics of the Nui Chua pegmatoid mafic-ultramafic series, Northern Vietnam: Significance in petrogenesis and Fe-Ti-V metallogenesis

The pegmatoid intrusions of the Nui Chua complex are one of the important mafic-ultramafic intrusive series associated with Fe-Ti-V ores in northern Vietnam. These intrusions consist of plagiowebsterite, clinopyroxenite, melanogabbronorite, mesogabbro, gabbronorite, and leucogabbronorite. The Fe-Ti oxide ores being massive or disseminated appear layered or veined in pegmatoid rocks. The geochemical characteristics of pegmatoid rocks are rich in Fe, Ti, V and poor Mg; their HREE are higher than LREE, with [La/Yb]N of 0.49 to 0.91 (average: 0.67), showing negative anomalies at Nb, Ta, Th, U, Sr, Zr and positive anomalies at Cs, Ti, and K. The chemical composition and distribution characteristics of trace and rare earth elements of mafic and ultramafic rocks show that they share the same magma source. Having the same geochemical tendency of intrusive formations, Fe-Ti oxide ores are magmatic origin associated with intrusive pegmatoid rocks. The pegmatoid rocks of the Nui Chua complex and Fe-Ti oxide ores are formed as a product of the fractional crystallization of Fe-Ti-rich residual melts after crystallization of the layered rocks.

The Use of Modern Physical Methods of Instrumental Analytics in the Study of Stromatolites

The use of X-ray microtomography, neutron tomography, scanning electron microscopy and X‑ray microanalysis in the study of stromatolites is discussed, and the advantages of each of these methods are summarized. Scanning electron microscopy allows study of the morphology of the object surface. Information about the composition and ratio of chemical elements of surface structures can be obtained using X‑ray microanalysis. X-ray microtomography will be useful for detecting internal structures and their localization in the sample. Neutron tomography can be used to search for organic matter and other hydrogen-containing compounds.

Evaluation of chemical composition, trace element content, antioxidant and antimicrobial activities of Verbascum pseudoholotrichum

Given that some Verbascum species are effective against influenza viruses, an endemic species, Verbascum pseudoholotrichum is thought to have the potential to be used in the treatment of virucidal diseases. It was extensively investigated for its antioxidant and antimicrobial activities, chemical and trace element composition. The soxhlet extraction method was applied in the extraction process of the above-ground parts of the plant using three solvents (methanol, ethanol and water). The total phenolic content of extracts was between 175.7 and 186.1 mg GAE/100 g on the dried weight basis. DPPH radical scavenging activity analysis was performed and IC50 values were 0.539–1.254 mg mL−1. In total, 38 compounds were detected by GC–MS analysis. ICP-MS analysis was applied to identify the total contents of 24 elements in dried samples. The antimicrobial activity of the extracts was evaluated on six different pathogens using the spectrophotometric microdilution technique. The obtained minimum inhibitory concentration values were 17.37 µ–113.9 µg mL−1 at the end of the 24-h incubation. The highest and lowest inhibition zones were 5.0 and 0.3 mm for ethanol extract against Bacillus subtilis and water extract against Enterococcus fecalis, respectively, and no resistance was seen against Escherichia coli using disc diffusion method.

Origin of the spinel-pyroxene symplectites in the harzburgites from the New Caledonia Peridotite

The New Caledonia ophiolite (Peridotite Nappe) hosts one of the largest and best-exposed mantle section worldwide, providing an exceptional insight into upper mantle processes. The Peridotite Nappe is mostly dominated by harzburgites, locally overlain by mafic-ultramafic cumulates, but also includes minor spinel and plagioclase lherzolites, cropping out in the northern part of the island. The New Caledonia harzburgites are low-strain tectonites, showing dominant porphyroclastic textures. The main mantle paragenesis is constituted by olivine (~ 75-85 vol%), orthopyroxene (~ 15-25 vol%) and spinel (< 1 vol%), while primary clinopyroxene is notably absent. An important textural feature of these mantle rocks is represented by the common occurrence of spinel-pyroxene symplectitic aggregates.In this work, we present a petrographical, textural and major element chemical characterization of the spinel-pyroxene symplectitic intergrowths occurring in the New Caledonia harzburgites (Kopeto, Central Massif, and Yate, Massif du Sud). Based on textures, size and relationships with the other mineral phases, these spinel-pyroxene clusters have been divided into two types, named type-A and type-B.Type-A symplectites occur in the Kopeto harzburgites and are composed of spinel-orthopyroxene (± clinopyroxene) intergrowths. In type-A symplectites, symplectitic spinel (Spl2) occurs as abundant vermicular shaped grains, ranging in size from ~ 0.5 to 2 mm. By contrast, spinel of the porphyroclastic assemblage (Spl1) shows smaller size (in the range of few m) and notably lower abundances (< 1%). Type-A symplectites develop exclusively on porphyroclastic olivine, which in turn displays evidence of chemical disequilibrium and corroded outlines. Bulk major element composition reconstructed for type-A symplectites rule out a derivation from a pre-existing garnet phase, as the model garnet compositions do not satisfy garnet stoichiometry, being characterized by Si deficiency. By contrast, major element chemical variations of the symplectitic phases, coupled with the high abundance of Spl2 and olivine resorption, suggest an origin from reactive percolation of opx-saturated hydrous melts or slab-derived fluids in a subduction zone setting.Type-B symplectites are found in Yate sample and consist of spinel-orthopyroxene (± clinopyroxene). They are characterized by smaller size (few hundreds of m, i.e. “micro-symplectites”) and different shapes compared to type-A symplectites, growing as vermicular, “myrmekite-like” intergrowths at the rims of porphyroclastic orthopyroxene. Major element chemical compositions of type-B symplectites are consistent with an origin as “cooling textures”. These structures may derive from unmixing of a high-T, Al-Cr rich, orthopyroxene due to the decreased solubility of the Cr-Al component (CrMgTs) during post-melting lithospheric cooling at T < 900°C.

Geochemistry and geochronology of the Jawornik granitoids, Orlica-Śnieżnik Dome, Sudetes, Poland

The Jawornik granitoids intrude, in vein-like form, a sequence of a polymetamorphic metavolcanic and metapelitic rocks of the Orlica-Śnieżnik Dome, Sudetes, Poland. This paper provides whole-rock geochemical data, sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon geochronological data as well as 40Ar-39Ar age determinations to constrain the genetic and temporal relationships of the different rock types forming these veins. Based on macroscopically visible features of the granitoids and their relationship with tectonic structures visible in the country rocks, four varieties of the Jawornik granitoids have been distinguished: amphibole- and biotite-bearing granites (HBG), biotite-bearing granites (BG), biotite- and muscovite-bearing granites (BMG) and muscovite-bearing granites (MG). The Jawornik granitoids as a whole show a limited but significant variation in major element chemical composition, with SiO2 ranging from 65 to 76 wt.% (average 69.16 wt.%, n = 24). They are subalkalic, peraluminous and calc-alkaline [average A/CNK = 1.07, average (Na2O + K2O) = 7.75, average (Fe2O3t/(Fe2O3t + MgO) = 0.59]. Close inspection of their geochemical parameters showed that the samples investigated can be subdivided into two groups. The first group, the HBG, BG, and BMG varieties, comprising most of the granitoids in the Złoty Stok-Skrzynka Tectonic Zone, were formed by melting of greywackes or/and amphibolites. The MG, belonging to the second group, were formed by partial melting of a more felsic source. The HBG yielded a zircon U-Pb age of 351 ±1.3 Ma and well-defined 40Ar-39Ar plateau ages for hornblende (351.1 ±3.9 Ma) and coexisting biotite (349.6 ±3.8 Ma), indicating probably the oldest magmatic event in this region. Zircons from the MG, the youngest rock variety on the basis of their relationship with the tectonic structures in the host rocks, yielded a U-Pb age of 336.3 ±2.4 Ma, though based on three points only. The biotites and muscovites from the BMG have 40Ar-39Ar plateau ages of 344.1 ±4.7 Ma and 344.6 ±3.8 Ma, respectively. These data, in combination with already published isotopic ages, suggest that the Jawornik granitoids intruded host rocks of the Orlica-Śnieżnik Dome in three stages, at ~350, ~344 and ~335 Ma.

Bifunctional cyclomatrix polyphosphazene-based hybrid with abundant decorating groups: Synthesis and application as efficient electrochemical Pb(II) probe and methylene blue absorbent

HypothesisThe construction of novel functional cyclomatrix polyphosphazenes (CPPs) hybrid, which with diverse decorating groups, is a challenging task due to the structural limitation of available reaction substrates (phenols and amines). ExperimentsHerein, a phenolic hydroxyl (OH) modified ployamide derivative (P2) was successfully prepared via novel benzoxazine-isocyanide chemistry (BIC). A kind of CPP hybrid (P3), which with abundant functional groups (amide, tertiary amine, benzoxazine and phenolic hydroxyl) was prepared subsequently by the condensation between P2 and hexachlorocyclotriphosphazene (HCCP). Chemical structure, elemental composition, morphology, porous properties and crystallinity of P3 were systematically analyzed here. The electrochemical detection of lead ion (Pb2+) was realized by using P3-modified glassy carbon electrode (GCE/Nafion/P3) as the working electrode. Besides this, given the unique chemical structure and morphology of P3, the selective adsorption of methylene blue (MB) by P3 was also studied here. FindingsExperimental results indicated that that P3 can act as bifunctional hybrid material to solve environmental issues.

Tourmaline Reference Materials for the In Situ Analysis of Oxygen and Lithium Isotope Ratio Compositions

Three tourmaline reference materials sourced from the Harvard Mineralogical and Geological Museum (schorl 112566, dravite 108796 and elbaite 98144), which are already widely used for the calibration of in situ boron isotope measurements, are characterised here for their oxygen and lithium isotope compositions. Homogeneity tests by secondary ion mass spectrometry (SIMS) showed that at sub‐nanogram test portion masses, their 18O/16O and 7Li/6Li isotope ratios are constant within ± 0.27‰ and ± 2.2‰ (1s), respectively. The lithium mass fractions of the three materials vary over three orders of magnitude. SIMS homogeneity tests showed variations in 7Li/28Si between 8% and 14% (1s), which provides a measure of the heterogeneity of the Li contents in these three materials. Here, we provide recommended values for δ18O, Δ’17O and δ7Li for the three Harvard tourmaline reference materials based on results from bulk mineral analyses from multiple, independent laboratories using laser‐ and stepwise fluorination gas mass spectrometry (for O), and solution multi‐collector inductively coupled plasma‐mass spectroscopy (for Li). These bulk data also allow us to assess the degree of inter‐laboratory bias that might be present in such data sets. This work also re‐evaluates the major element chemical composition of the materials by electron probe microanalysis and investigates these presence of a chemical matrix effect on SIMS instrumental mass fractionation with regard to δ18O determinations, which was found to be &lt; 1.6‰ between these three materials. The final table presented here provides a summary of the isotope ratio values that we have determined for these three materials. Depending on their starting mass, either 128 or 512 splits have been produced of each material, assuring their availability for many years into the future.

Technogenic Magnetic Particles in Soils and Ecological–Geochemical Assessment of the Soil Cover of an Industrial City in the Ural, Russia

The work is devoted to the study of pollution by technogenic magnetic particles and heavy metals of soils in the city of Gubakha, Middle Ural (Russia). The aim of the work is the ecological and geochemical assessment of the elemental chemical composition of the soils of the city of Gubakha, and the establishment of the geochemical role of technogenic magnetic particles (TMPs). For the first time, the regularities of the spatial distribution of magnetic susceptibility in the soils of the city of Gubakha were revealed, and the morphology, elemental and mineralogical compositions of magnetic particles in the soils of an industrial city in the Middle Urals were characterized using the methods of the chemical extraction of iron compounds, magnetic separation, ESEM/EDS, and Mössbauer spectroscopy. The magnetic phase of soils contains magnetite/maghemite, hematite, pyrrhotite, intermetallic alloys and chromite. Spherical magnetic particles are hollow, and have a magnetite shell and a varied surface texture. The crystal lattice of magnetite is characterized by low stoichiometry. The heavy metals Zn, Cu, Ni and Cr are concentrated in magnetic particles and have a high correlation coefficient with magnetic susceptibility. The level of contamination of Cu, Ni, Zn, Cr and Mn in the soils of a residential zone of Gubakha, estimated by the value of the pollution load index (PLI), was high. The Igeo index for Fe ranges from 6.2 to 12.2, for Cu–1.1 and Ni–1.1. The combination of methods for measuring magnetic susceptibility, determining the mineralogical composition of iron compounds, and determining the elemental chemical composition by X-ray fluorescence, has shown the effectiveness of an integrated approach for carrying out an ecological–geochemical assessment of the soil cover of Gubakha.