Zircons from Collisional Granites, Garhwal Himalaya, NW India: U–TH–Pb Age, Geochemistry and Protolith Constraints

In the present work, we studied zircons from the less foliated granites of the Chail Group, which form a thrust sheet of the Lesser Himalayan Sequences, Garhwal region. Compositionally, these granites are S–type, formed in a collisional tectonic setting. Zircons possess an internal structure, mineral inclusions, and geochemical characteristics typical of magmatic origin. The U–Th–Pb geochronology and geochemistry were assessed using the laser ablation multi–collector inductively coupled plasma spectrometry (LA–ICP–MS) technique. U–Th–Pb isotope dating of zircons from two different samples revealed their age, estimated from the upper intersection of the discordia, to be 1845 ± 19 Ma. Zircons from one sample contained inherited cores belonging to three age groups: Paleoarchean (3.52 Ga), Neoarchean (2.78 Ga and 2.62 Ga), and Paleoproterozoic (2.1 Ga). Zircons with ages of 3.52, 2.62, and 2.1 Ga were interpreted as magmatic based on their geochemical characteristics. The 2.78 Ga core was interpreted as metamorphic. The observed inheritance is consistent with the melting of sedimentary rocks. The inherited zircons could have originated from Aravalli and Bundelkhand Craton and Paleoproterozoic Aravalli Fold Belt rocks. This confirms that the studied granites are S–type and could have been formed in a collisional environment at 1.85 Ga on the western flank of the Columbia Supercontinent.

HEAVY METAL CONTAMINATION IN VEGETABLES AND ITS DETECTION: A REVIEW

The quality of marketed vegetables cannot be guaranteed as many of them has been contaminated with heavy metals such as lead, cadmium and arsenic. These heavy metals can act as either growth supporter or threat depending on their types and amount absorbed by the plants. The consumption of an excessive amount of heavy metals in vegetable may cause several diseases such as renal dysfunction and bone depletion. There are few methods used to detect heavy metal contamination such as Atomic Absorption Analysis (AAS), Neutron Activation Analysis (NAA), X-ray Fluorescence Spectroscopy (XRF) and Inductively Coupled Plasma Spectrometry (ICPMS). This paper discusses all these methods to compare their efficiency, advantages and disadvantages to select the best method for heavy metal detection in vegetables.

Geochronological and geochemical features of magmatic gold- and silverbearing complexes in the Chukotka sector of the Russian Arctic coast

Research subject. This study was devoted to magmatic complexes in Northwestern Chukotka associated with the largest gold and silver deposits across Kupol’skii (Kupol field) and Ilirnei (Dvoinoe and September fields) ore junctions. Materials and methods. The petrogenic elements of ore-containing igneous rocks were determined using a spectrometer ICAP 6500Duo (USA). An elemental analysis of igneous and ore samples was performed by inductively coupled plasma spectrometry (ICP-MS). The age was determined by zircons (SHRIMP-II, VSEGEI isotope research center, St. Petersburg) using a laser ablation system NWR-213 (USA). Results. New information concerning the dating of magmatic complexes and gold-bearing magmatic systems in the ore junctions under study was obtained. It was established that the manifestations of magmatism in the Kupol and Ilirnei ore junctions differ in terms of the main phase formation age. The age of the Ilirnei ore junction, which is represented by large-volume intrusions of granitoids, leucogranites and volcanites of medium-basic composition, was determined to be 124–114 Ma. The age of mineralization, which is associated with later magmatism phases – small intrusions and a dike complex of predominantly granodiorite composition –, was estimated to be (93– 92) ± 2.0 Ma. In the Kupol ore junction, the magmatism associated with mineralization was dated 91.0 ± 1.4 Ma, while the age of rhyolite dikes containing mineralization was estimated to be 88.9–89.0 Ma.Conclusion. The results of the RMS analysis of the Kupol and Ilirney ore junctions suggest that ore formation in this region was connected with a single stage of activation of deep processes and mantle-crust interaction with participation of deep (mantle) fluids.

Laser Ablation Inductively Coupled Plasma Spectrometry: Metal Imaging in Experimental and Clinical Wilson Disease

Wilson disease is an inherited disorder caused by mutations in the ATP7B gene resulting in copper metabolism disturbances. As a consequence, copper accumulates in different organs with most common presentation in liver and brain. Chelating agents that nonspecifically chelate copper, and promote its urinary excretion, or zinc salts interfering with the absorption of copper from the gastrointestinal tract, are current medications. Also gene therapy, restoring ATP7B gene function or trials with bis-choline tetrathiomolybdate (WTX101) removing excess copper from intracellular hepatic copper stores and increasing biliary copper excretion, is promising in reducing body’s copper content. Therapy efficacy is mostly evaluated by testing for evidence of liver disease and neurological symptoms, hepatic synthetic functions, indices of copper metabolisms, urinary copper excretions, or direct copper measurements. However, several studies conducted in patients or Wilson disease models have shown that not only the absolute concentration of copper, but also its spatial distribution within the diseased tissue is relevant for disease severity and outcome. Here we discuss laser ablation inductively coupled plasma spectrometry imaging as a novel method for accurate determination of trace element concentrations with high diagnostic sensitivity, spatial resolution, specificity, and quantification ability in experimental and clinical Wilson disease specimens.

Synergistic effect between CO2 and H2O2 on ethylbenzene oxidation catalyzed by carbon supported heteropolyanion catalysts

A series of Keggin heteropolytungstate salts (M1.5PW12O40, M=Cu, Co, Zn and Fe) were prepared and characterized utilizing inductively coupled plasma spectrometry (ICP), Fourier transform infrared (FTIR) spectra, and ultraviolet-visible (UV-Vis) light spectroscopy. The as-prepared catalysts were tested for the oxidation of ethylbenzene by using carbon dioxide/hydrogen peroxide (CO2/H2O2) as the oxidizing agent system under solvent-free conditions. The results indicated that the heteropolytungstates catalyzed the side chain oxidation of ethylbenzene leading to acetophenone as a major product. The effect of various reaction parameters on ethylbenzene oxidation over the best catalyst of the series, namely Co1.5PW12O40 loaded on activated carbon (AC), was investigated. It was found that the selectivity depends strongly on the reaction temperature. Higher reaction temperatures reduce the conversion due to the decomposition of H2O2. Oxidation by a large amount of H2O2 decreases the conversion owing to a decrease of the solubility of ethylbenzene in an aqueous medium, and favors the oxidation of the reaction products, which are more soluble in an aqueous medium. The increase of the CO2 pressure improves both the conversion and the selectivity of acetophenone due to the involvement of the percarbonate species (HCO4−) responsible for oxidation by oxygen transfer.

Presence of radionuclides and toxic elements in feedstuffs and food of animal origin

Introduction. The aim of this study was to determine the content of radionuclides and toxic elements in samples feedstuffs and food of animal origin collected between 2007- 2017 from two suburban areas of Belgrade, the municipalities of Palilula and Surcin, both areas with intensive agricultural production. Materials and Methods. Radionuclides (40K and 137Cs) and toxic elements (As, Cd, Cu, Ni, Pb and Zn) were determined in samples of corn, hay, meat, milk and eggs, by gamma ray spectrometry and inductively coupled plasma spectrometry (ICP-OES, Spectro Genesis). Results and Conclusions. The obtained results showed that natural 40K was present in all investigated samples. The average activity concentration of 40K was 94 Bq/kg in corn, 117 Bq/kg, 108 Bq/kg and 95 Bq/kg in beef, pork and chicken meat, respectively, as well as 61 Bq/kg in cow?s milk and 48 Bq/kg in eggs. Anthropogenic radionuclide 137Cs was not detected. The trend for toxic element levels according to the average concentrations found in the studied feed samples (corn and hay) was as follows: Zn>Cu>Pb>As>Ni>Cd. Arsenic was detected in animal feed in both Belgrade municipalities, with the average concentration being 1.08 mg/kg (0.5-1.37 mg/kg), and in corn, the As content was higher than in hay samples. In food of animal origin, only Zn and Cu were detected. It is concluded that the presence of radionuclides and toxic elements in feedstuffs and foods of animal origin does not pose a health risk for either humans or animals.

Air pollution monitoring with mosses in Western Rhodopes, Bulgaria

For the first time a complex study of the bioaccumulation of 22 macro- and microelements, as well as of 18 rare earth and radioactive elements in mosses was applied in the territory of Western Rhodopes. The research is a part of the international program (ICP Vegetation, UNECE) that has been carried out in most of the European countries since 1987. Certain local emitters like old and open mines, serpentines, as well as cross-border transmission were identified. In addition, highest concentrations of radioactive elements were registered in the area of an old uranium mine and most elevated sites, probably due to increased wet deposition. Both heavy metals and toxic elements, as well as radioactive elements maxima were lower than measured highest levels for Bulgaria and Europe. In such studies, inductively coupled plasma spectrometry (ICP-OES, ICP-MS) could be recommended.