Atomic Emission Research Articles

Qualitative Geochemical Analysis of the 2004 Indian Ocean Giant Tsunami Deposits Excavated at Seungko Mulat Located in Aceh Besar of Indonesia Using Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was employed to characterize the geochemical signatures layer by layer of 2004 Indian Ocean tsunami deposits in Seungko Mulat Village, Aceh Province, Indonesia. In the LIBS experimental setup, a Nd-YAG laser beam is directed towards the deposit samples, and the resulting atomic emission lines from the laser-induced plasma are captured using a spectrometer. Our analysis reveals terrestrial indicators (Fe), heavy metals (Cu, Cr, Co, Cd), and increased emission intensity of Mg, Ca, Al, K, Si, Ba, N, and O in the 2004 Indian Ocean tsunami layers. The emission intensity ratios of several elements in the 2004 Indian Ocean tsunami deposit layers, namely Ca/Ti, Si/Ti, and K/Ti, unveil notable disparities among the elements evaluated. This indicates the possibility of utilizing these ratios as reliable geochemical markers to differentiate the layer by layer of tsunami deposits. LIBS surpasses XRF in detecting nearly all elements simultaneously and identifying both light elements and specific heavy metals (Ba, Cu, Cr, Co, Cd, Pb, Ni, V, W), exceeding XRF's detection capabilities. This study emphasizes the effectiveness of LIBS as an advanced optical technique, offering speed and promise in analyzing layer-by-layer geochemical markers of the 2004 Indian Ocean tsunami deposits in Seungko Mulat Village.

Analysis of transition metals in glioblastoma tumor and plasma samples.

e14029 Background: Transition metals such as copper, iron, zinc, and manganese are known to play essential roles in human physiology as evidenced in conditions where these metals are dysregulated. The role of transition metals in glioblastoma biology has been largely understudied. Here we investigated whether plasma and tumor transition metal content is associated with glioblastoma patient outcomes. Methods: Transition metal content was measured in 31 glioblastoma tumor samples, 21 of which had matched plasma samples, using inductively coupled plasma mass spectroscopy (ICP-MS) or inductively coupled plasma atomic emission spectroscopy (ICP-AES). Concentrations of transition metals in plasma and tumor were then then correlated with clinical parameters including median overall survival (mOS) as well as plasma cytokines. Results: Spearman correlation analysis of transition metals in glioblastoma tumor samples found that tumor manganese and tumor zinc (R = 0.52, p = 0.0048) as well as tumor copper and tumor zinc (R = 0.36, p = 0.038) were positively correlated. Plasma transition metal content did not correlate with tumor transition metal content. Kaplan-Meier and Cox regression survival analysis between high and low expressors of each respective transition metal, separated at the median, revealed that high plasma iron content was associated with prolonged survival (median overall survival: 30.1 vs 12.4 months, P = 0.0036). Plasma from glioblastoma patients in the high plasma iron group had increased levels of IFN-β (10.91 pg/mL vs 7.43 pg/mL, P = 0.004). Plasma or tumor concentrations of copper, zinc, or manganese did not associate with survival. Conclusions: Increased plasma iron content is associated with prolonged survival as well as increased plasma IFN-β levels, suggesting a possible link between iron and immune responses in glioblastoma patients.

Assessment of essential and toxic trace element levels in erythrocytes of hemodialysis patients with end-stage renal disease

BackgroundChronic kidney disease (CKD) is a global public health problem, resulting in end-stage kidney disease, cardiovascular disease, and premature death. AimThe aim of the study was to determine the profile of essential and toxic trace elements in erythrocytes of patients with end-stage renal disease (ESRD) and their relationship with selected anthropometric and biochemical parameters. MethodsThe present study compared the profiles of trace elements, including toxic sub-stances, in the erythrocytes of 80 hemodialysis patients with CKD with 40 healthy subjects. All patients had stage 5 CKD. The levels of Cd and Pb were determined by graphite furnace atomic absorption spectrometry and levels of Fe, Mn, Zn, Cu Cr, Ni, and Li by inductively coupled plasma atomic emission spectrometry. ResultsThe ESRD patients demonstrated significantly lower Fe and Zn concentrations and significantly higher Mn and Li and toxic Pb and Cd concentrations in erythrocytes compared to those of the healthy controls. Negative correlations were observed, among others, between the concentrations of Cu, Li, and creatinine; Cu and phosphates; Mn, Pb, and transferrin saturation while positive correlations were noted between Cu, Cr, and transferrin and Pb, Cr, and the normalized protein catabolism rate. ConclusionsThe higher concentrations of toxic elements present in the erythrocytes of CKD patients might have resulted from the reduced ability of the kidneys to excrete them. Moreover, differences in the concentrations of essential elements (Fe, Mn, Zn) between the two groups indicated that their resorption in the kidneys of CKD patients was impaired. Patients with CKD might benefit from interventions intended to reduce high, toxic concentrations of Pb and Cd and Li and Mn as an alternative supportive treatment. Iron and zinc supplementation should be a component for the treatment of anemia in CKD patients.

Mineral Composition of Blackcurrant (Ribes Nigrum L.) Fruits and Leaves

Background Plants as living systems are characterized by the appropriate degree of accumulation of macro- and microelements, which, acting as factors of the external environment, are basic modulators for synthesizing biologically active substances. Blackcurrant (Ribes nigrum L., Grossulariaceae) is widespread worldwide. Berries, leaves, and buds are medicinal raw materials in folk medicine. The regularity of inorganic elements accumulation in this plant and their impact on the quality of raw materials are topical and need to be studied. Aims This work aimed to study the mineral composition of R. nigrum raw materials collected in Western Ukraine (Ivano-Frankivsk and Ternopil regions) and find the regularity of their accumulation in the plant parts and from the soils. Methods The elemental compositions of R. nigrum fruits and leaves, as well as the soils of the growth places, were studied using the method of atomic emission spectrometry with inductively coupled plasma iCAP 7000 Duo. Results The content of 19 inorganic elements in R. nigrum raw materials was established. Their quantities don’t differ significantly depending on the growth places. All the fruits had high K, Na, Mg, P, and Ca contents, which were slightly lower in leaves. Thus, the fruits contain 590-675 mg/kg of Mg, while in leaves, there are just 98-106 mg/kg. Most of Fe was accumulated in the fruits (73-85 mg/kg). The content of Mn was observed in the leaves (57-64 mg/kg), slightly higher than in the fruits (47-51 mg/kg). The content of heavy metals in the objects was within the permitted limits of European Pharmacopeia. The results testify to the inverse relationship between the content of most elements in the soils and the coefficient of their accumulation in the plant. Conclusion The content of macro- and microelements in R. nigrum fruits and leaves had similar profiles but differed in their quantitates. The regularity of element accumulation in R. nigrum raw materials corresponds to the following profile in accordance with their quantitative content in the raw materials: K> Na> P> Mg> Ca> Si> Fe> Mn> Al> Se> Zn> Cu> Co> I> Pb> Ni> Mo> Sr> Cd. The regularity of their accumulation in the plant parts from the soils was established.

Microstructure and corrosion behaviour of Mg-1Sc alloy with different processing conditions

The microstructure and corrosion resistance of Mg-1Sc alloys in different processing conditions were investigated. The composition was examined by Inductively Coupled Plasma Atomic Emission Spectrometer, the microstructure was analyzed by metallographic microscope. The corrosion behaviour of the alloy was investigated by hydrogen evolution tests and electrochemical tests. The results showed that as-cast and rolled Mg-1Sc possess better corrosion resistance compared with extruded Mg-1Sc alloys, which is due to the fact that the extrusion flow lines and residual stresses caused by machining in extruded Mg-1Sc alloys can lead to easier corrosion. In addition, rolled Mg-1Sc alloy shows better corrosion resistance than as-cast alloy, which is attributed to the finer grain sizes and a denser corrosion product film.

Effects of Pinealectomy and Melatonin Supplementation on Elements Metabolism in Rat Testicular Tissue

Objective: The aim of this study was to investigate how pinealectomy and melatonin application affect elements metabolism in rat testicular tissue. Methods: The study was carried out on 32 adult male Spraque-Dawley rats. Animals were divided into 4 equal groups. Group 1: Control, Group 2: Melatonin, Group 3: Pinealectomy, Group 4: Pinealectomy+Melatonin. Group 2 and 4 animals received daily 3mg/kg intraperitoneal (ip) melatonin supplementation for 4 weeks. The pineal glands of Group 3 and 4 animals were removed under general anesthesia. At the end of the applications, testicular tissue samples were taken from the animals sacrificed under general anesthesia. Elemental determinations (µg/gram/tissue) were performed in testicular tissue samples using the atomic emission method. Results: The highest cobalt, molybdenum, nickel, manganese, phosphorus, and sodium levels (p<0.001) and the lowest potassium levels in the testicular tissue were obtained in the pinealectomy group (group 3) (p<0.001). Magnesium and selenium values in testicular tissue were highest in the pinealectomy group (group 3) (p<0.001), and were higher in the pinealectomy+melatonin group (group 4) than ingroup 1 (control) and group 2 (melatonin) (p<0.001). Testicular zinc levels were highest in group 2, where melatonin was administered, and lowest in group 3, which was the pinealectomy group (p<0.001). Conclusion: The findings obtained as a result of the study show that pinealectomy significantly disrupts element metabolism in the testicular tissue of rats, and melatonin supplementation may have a regulatory effect on testicular elemental metabolism.

Led-induced deposition of Pt and Au NPs on carbon fibers: Developing a novel strategy for facile fabrication of electrocatalysts for enhanced methanol electrooxidation

In addressing the imperative of aligning materials science with sustainable development, our study introduces an innovative method for the simultaneous deposition of Pt and Au nanoparticles onto a carbon support. This research represents the pioneering application of the photodeposition process for synthesizing bimetallic nanoparticles on a carbon matrix. The comprehensive characterization of the resulting nanostructures involves various techniques, including field X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), atomic force microscopy (AFM), energy-dispersive X-ray analysis (EDX), inductively coupled plasma atomic emission spectroscopy (ICP-OES), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetric techniques. Our findings reveal that the photodeposition method produces a homogeneous AuPt nanostructure, demonstrating superior electrocatalytic activity in methanol oxidation compared to the monometallic carbon fiber_Pt (CF_Pt) catalyst. These results emphasize the effectiveness of our novel approach in fabricating electrocatalysts with exceptional performance in methanol oxidation reactions.

Trace Elements Distribution in the k7 Seam of the Karaganda Coal Basin, Kazakhstan

We investigated the distribution patterns and evaluated the average contents of trace elements in the k7 seam of the Karaganda coal basin in Central Kazakhstan. This paper presents the results of studying the geochemistry of 34 elements in 85 samples of the k7 seam. The study employed a suite of advanced high-resolution analytical methods, including atomic emission spectrometry with inductively coupled plasma (ICP–OES) and mass spectrometry with inductively coupled plasma (ICP–MS), along with their processing and interpretation. It was determined that the concentrations of trace elements in the k7 seam are primarily associated with lithophile elements, revealing high concentrations of Li, V, Sc, Zr, Hf, and Ba. Additionally, increased concentrations of Nb, Ta, Se, Te, Ag, and Th were observed compared to the coal Clarke. Specific Nb(Ta)–Zr(Hf)–Li mineralization accompanied by a group of associated metals (Ba, V, Sc, etc.) was identified. The study revealed lateral and vertical heterogeneity of the rare elements’ distributions in coals, attributed to the formation dynamics of the coal basin. A correlation between Li and Al2O3 with a less positive relationship with K2O suggests the affinity of certain elements (Li, Ta, Nb, and Ba) to kaolinite. Clay layers showed increased radioactivity, with Th—13.2 ppm and U—2.6 ppm, indicating the possible presence of volcanogenic pyroclastic rocks characterized by radioactivity. Taken together, these data reveal the features of the rock composition of the source area, which is considered a mineralization source. According to geochemical data, it was found that the source area mainly consists of igneous felsic rocks, indicating that the formation occurred under conditions of a volcanic arc. This study’s novelty lies in estimating the average trace elements in the k7 seam, with elevated concentrations of certain elements that suggest promising prospects for industrial extraction from coals and coal wastes. These findings offer insights into considering coal as a potential source of raw material for rare metal production, guiding the industrial processing of key elements within coal. The potential extraction of metals from coal deposits, including from dumps, holds significance for industrial and commercial technologies, as processing critical coal elements can reduce disposal costs and mitigate their environmental impact.

A search for transient, monochromatic light in a 6-deg swath along the galactic plane

ABSTRACT We searched the Milky Way Plane along a 6-deg swath for pulses of monochromatic light as faint as 15th mag (V band) using a wide-field telescope equipped with a prism. Pulses with duration less than 1 s that occur more often than once every 10 min would be detected, and pulses arriving less frequently would be detected with proportionally lower probability. A ‘difference-image’ algorithm revealed 36 monochromatic sources. Subsequent assessment showed all were simply astrophysical objects emitting known atomic emission lines. No unexplainable monochromatic emission, pulsed or continuous, was detected. The detection threshold corresponds to an ∼70 GW laser having a diffraction-limited 10-m aperture 1 kpc away (depending on wavelength). Past all-sky optical and radio-wave surveys revealed thousands of unexpected objects exhibiting extraordinary spectral emission, but none were technological. Hypotheses of our Milky Way Galaxy teeming with advanced life must be demoted.

A technique for depositing iron, tungsten, molybdenum, and chrome in the determination of selenium and tellurium in alloy steel by ICP-AES method

Direct determination of the content of selenium and tellurium impurities in metallurgical materials by the method of inductively coupled plasma atomic emission spectroscopy (ICP-AES) is difficult due to spectral and non-spectral interference from macrocomponents present in the materials under study. The separation of micro-(Se, Te) and macro-components (Fe, W, Mo, Cr, Cu, Ni, Co) through preliminary precipitation is the goal of the study. The use of barium acetate and sodium fluoride as precipitants are shown to provide an effective separation of Se and Te from Fe, W, Mo, and Cr (the content in the analyzed solution is less than 0.1 wt.% of the original) and partial separation from Cu, Ni, and Co (the content in the analyzed solution from 25 to 55 wt.% of the original). Optimal conditions for the deposition of macrocomponents (Fe, W, Mo, Cr) and inhibition of the process of coprecipitation of selenium and tellurium on sediments of macrocomponents for their subsequent ICP-AES determination were determined. The optimal pH for the precipitation of macrocomponents equals 1. The optimal mass of precipitants (barium acetate and sodium fluoride) is 10 and 3 g, respectively. To inhibit the process of coprecipitation of selenium and tellurium on sediments of macrocomponents, it is proposed to use hydrofluoric acid. The optimal volume of hydrofluoric and hydrochloric acids for inhibiting the process of coprecipitation of analytes on sediments of macrocomponents was determined (3 and 6 cm3, respectively). The developed procedure for separating micro-Se, Te from macro-components was tested on standard samples of alloyed steels using the «spike» method. The technique is characterized by satisfactory accuracy and reproducibility, the limit of determination of analytes after separation of macrocomponents is 10–3 wt.%.

MACRO- AND MICROELEMENT COMPOSITION OF THE HERB AND ROOTS OF HAPLOPHYLLUM DAURICUM (L.) G. DON.

Haplophyllum dauricum is a rich source of lignans with antitumor activity. It has been actively used in the practice of Traditional medicine. In addition to lignans, the chemical composition of the species is represented by coumarins, flavonoids, alkaloids and essential oils. However, the composition of the elements of the species, which are necessary for the development of quality criteria of medicinal plants, has not been studied before. In this regard, the purpose of the work was to study the content of macro- and microelements in the aboveground and underground parts of Haplophyllum dauricum of the flora of Buryatia and Transbaikal territory. The content of the following elements was determined by inductively coupled plasma atomic emission spectrometry: Li, Be, Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Zr, Mo, Cd, Sb, Te, Ba and Pb. The content of Hg was determined by the "cold steam" method using an atomic absorption analyzer. According to the obtained data, Haplophyllum dauricum is a rich source of calcium, potassium, magnesium and phosphorus, which were dominant. Among the microelements, iron and titanium were in highest concentration, which were accumulated mainly in the underground part of the plant. The content of heavy metals did not exceed the maximum permissible concentration established by the State Pharmacopoeia of the Russian Federation.

A multiparameter sensing spectroscopic system for remote plastic sorting with a single laser shot: a first information report

The spectroscopic methods have been widely applied for plastic characterization and sorting to assist the recycling process. However, most of the reported works have been carried out in conventional laboratory conditions. In this study, we discuss development and application of a single-shot standoff multimodal LIBS-Raman spectroscopy system for plastic identification by modifying existing optical models for such analyses. By utilizing a unique co-axial back-collection optical geometry in standoff signal collection and a direct signal coupling scheme, the system was able to sense LIBS-Raman signals from plastics in single laser shot mode within 20 ms, with a non-gated CCD detector remotely. We examine the application of the system in characterizing four commodity plastic types of polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), and polystyrene (PS)) based on atomic emissions (LIBS) and molecular structure (Raman Spectroscopy) by analyzing the respective standoff spectral data recorded from a distance of 4 m. The capability of the system to classify plastics based on standoff data is evaluated by using principal component analysis (PCA), which shows good segregation of the plastic classes depending on the intrinsic spectral features.

Electrical impedance spectroscopy for potassium content analysis and botanical origin identification of honey

Minerals are reported to dominate the electrical properties of honey and indicate its botanical and geographical origins. In this study, Electrochemical Impedance Spectroscopy (EIS) was used to assess the relation between mineral elements, electrical properties and botanical origin using three honey varieties - Citrus sp., Eucalyptus sp., and Erica sp. These varieties are identified through pollen analysis and market labelling. Flame atomic absorption and emission spectroscopies were used to quantify the concentrations of eight elements (potassium, sodium, calcium, magnesium, manganese, zinc, copper, and iron). Among all the mineral elements, potassium showed a consistent correlation with impedance. The potassium estimation in honey and standard solutions (calibration curve) had similar sensitivities of 153.43 nF/mM and 132.68 nF/mM, respectively. Additionally, the analysis revealed that potassium dominates the mineral composition, with the other species present in minimal quantities. The EIS technique showed high sensitivity to potassium and other ionisable species, making it possible to classify the botanical origin of these three honey types. The EIS technique proved to be both time and cost effective, yielding a classification rate higher than that achieved by analysing mineral composition.

Adsorption of Cd and Mn from neutral mine effluents using bentonite, zeolite, and stabilized dewatered sludge

This study aimed to investigate the adsorption efficiency of Cd and Mn using natural sorbents—bentonite, zeolite and stabilized digested dewatered waste sludge. The main contributions of the scientific article are in adding to the scientific knowledge of the use of natural and waste sorbents in the removal of heavy metals from neutral mine effluents. Current studies mainly focus on metal removal by sorption using natural sorbents from acid mine drainage. This study investigates sorption in neutral mine drainage. The efficiency of the sorption process was evaluated using the following parameters: efficiency (%) of metal ion removal, Freudlich and Langmuir adsorption isotherm constant. The AES–ICP method (atomic emission spectrometry with inductively coupled plasma) was used for the initial metal analysis of the materials used. The atomic absorption spectrometry (AAS) method was used for the analysis of Cd and Mn in the sorption process. The maximum efficiency of Mn removal by bentonite at the end of the test was approximately 90%. The removal of Mn by zeolite was considerably lower—about 20% compared to the use of sludge—80%. Based on the sorption efficiency, the sludge was suitable for sorption. Much higher levels of Cd sorption were achieved using sludge compared to using natural bentonite and zeolite. The main novelty of the work lies in the sorption of metals using dewatered digested sludge. Previous studies have focused on metal sorption using activated sludge. Most previous studies focused on sorption from acid mine drainage. The novelty of this study is that we focused on the sorption of neutral mine drainages, which are typical for the location we are monitoring.

Real-time monitoring of Ti-Nb-Ta-Zr and commercially pure Ti interaction with H2O2 using atomic force microscopy and atomic emission spectroelectrochemistry

This study offers a new approach to analyze surface behavior of titanium biomaterials during their exposure to the H2O2-enriched fluid which simulates post-operative inflammatory conditions. In this work in situ AFM and AESEC tests were exploited to study the origin of initial inflammatory-induced degradation for commercially pure Ti (CP-Ti) and Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy. Overall results indicate that initial interaction between H2O2 and TNTZ surface results only in dissolution of the alloy, while for CP-Ti both oxide formation and dissolution give important contribution to the degradation process. Proposed methodology yields insight into the origin of corrosion properties registered during standard electrochemical tests that are used to evaluate biomaterials.

Bay Laurel of Northern Morocco: A Comprehensive Analysis of Its Phytochemical Profile, Mineralogical Composition, and Antioxidant Potential

Laurus nobilis, sometimes referred to as laurel, has been used for medicinal and culinary purposes for a very long time. The main subjects of this study are the phytochemical composition, mineralogical profile, and potential antioxidant properties of Laurus nobilis in Tangier, Northern Morocco. For phytochemical analysis of methanolic extracts, high-performance liquid chromatography (HPLC-UV-MS) was used, and Fourier transformation infrared spectroscopy (FT-IR) was used to identify each individual component. Minerals were studied by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and wavelength dispersive X-ray fluorescence (WD-XRF). Total tannin, flavonoid, and phenolic amounts were quantified using aqueous and methanolic extracts. The antioxidant properties were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) assays. Research has revealed a complex array of phytochemicals, including tannins, flavonoids, and phenolic acids. Mineral analysis has revealed the existence of vital components that are beneficial to health. Comparing the methanolic extract to the water extract, it demonstrated higher levels of phenols, flavonoids, and tannins as well as stronger antioxidant activity, indicating greater health benefits. This comprehensive study highlights the importance of Laurus nobilis from Northern Morocco as a reliable botanic resource with potential pharmaceutical, nutritional, and cosmetic uses.

Silicon extraction from x-ray amorphous soil constituents: a method comparison of alkaline extracting agents

The growing interest in amorphous silica (ASi) within the fields of soil science and ecology underscores the necessity for a reliable protocol to estimate ASi contents in soil. Alkaline wet chemical extraction methods are commonly employed for silicon (Si) extraction from operationally defined (x-ray) amorphous Si phases or short-range ordered mineral phases in soils and marine sediments. In our study we conducted a comparative analysis of four alkaline extraction methods (1% sodium carbonate, 0.5 M sodium carbonate, 0.2 M sodium hydroxide, and 0.1 M Tiron), assessing their extraction selectivity as well as effectiveness using soils artificially enriched with varying, defined amounts of ASi. While extraction effectiveness was evaluated by determining the recovery rate of initially added ASi, extraction selectivity was determined by measuring aluminum (Al) and iron (Fe) concentrations as indicators of the dissolution of non-target mineral phases. Microwave plasma atom emission spectrometry was used to analyze Al, Fe, and Si concentrations in the extracts. Our results indicate that extraction with 0.2 M sodium hydroxide yields the best outcomes in terms of both extraction effectiveness and selectivity. This more recent extraction technique is conducted at the most alkaline pH (13.3) of all four methods tested, but at ambient temperature (21°C) decreasing the dissolution of non-target mineral phases. Though, no wet-chemical extraction used on heterogeneous samples like soil is precisely selective, and thus able to quantify the target analyte only. Hence, data obtained by such procedures still need to be interpreted with caution considering all their limitations.

Geological and geochemical analyses of pegmatites in Egbe, Isanlu (sheet 225), Southwestern Nigeria

The hitherto pegmatite of the Egbe area has been known to bear valuable economic minerals. They are associated with other rock types including banded gneiss, schist, amphibolite, and granites. These pegmatites and the host rocks were studied in detail to elucidate their petrochemical and geochemical features and also to assess the mineralization of Tantalum- iobium and other minerals. Geological field mapping was done, thin section-petrographic analysis of ten representative rock samples was performed and nineteen whole-rock samples were analyzed for major and trace elements including REES aided by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Boron- Fusion-Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), and Ion-Selective Electrode (ISE) for Fluorine at Acme Laboratory, Vancouver, Canada. The general structural trend of the area under study is WNW-ESE and foliations of N-S strike were observed in the banded gneiss and schist which also exhibit asymmetric and isoclinals folding respectively. The tantalite-columbite mineralization is associated with the NE-SW trending pegmatite dykes. The mineralized pegmatites are genetically related to the peraluminous S-type granite. The minerals (i.e., Albite, lepidolite and muscovite) extracted from the pegmatites are well enriched in Li, Rb, Cs, Nb and Ta compared to the host rocks. The rare-metal pegmatites exhibit pronounced negative Ce and Eu anomalies and also show weak negative Yb anomalies while the barren pegmatites have positive Ce and weak negative Eu anomalies and exhibit weak positive Yb anomalies. The pegmatites are moderately evolved compared with other highly mineralized pegmatites. The pegmatites from Igbaruku and one from the Okere area are of the rare-metal pegmatite and they are moderately fractionated while the barren pegmatite from Egbe and one from Okere are unfractionated. The economic mineral within the Egbe area is tantalite, with every possibility that the tantalite-columbite enrichment is ferrotantalite-columbite and manganotantalite columbite.

Evaluation of carcinogenic risk of heavy metals due to consumption of rice in Southwestern Iran

Pollution by heavy metals is a serious global problem due to its toxicity, abiotic characteristics, abundant sources, and cumulative behavior. On the other hand, considering the importance of rice consumption as an important part of nutrition in Lordegan and Ahvaz cities, this study was conducted to evaluate the carcinogenic risk of heavy metals lead, cadmium, zinc, nickel and in local Champa rice cultivated in these two cities. 16 Champa rice samples were collected from the fields of Lordegan and Ahvaz cities. The elements were read in three replicates by Varian 710-ES atomic emission device. The results showed that the concentration of cadmium and nickel in the cultivated rice in the two studied cities was within the range of the national standard of Iran and the Codex standard. Carcinogenic risk values for lead, cadmium and nickel in Champa Lordegan and Ahvaz rice were within the safe range. Also, the non-carcinogenic risk for these heavy metals in the two studied areas was less than 1 and was in the safe range. Rice pollution in Champa in Ahvaz can be due to the industrial nature of this city, and in Lordegan, it is due to pollution through pesticides, chemical fertilizers, and transportation. Long-term consumption of contaminated rice may endanger the health of residents of these areas. It is recommended to carry out regular and up-to-date monitoring strategies in these two cities to prevent the entry of these toxic heavy metals into the human food chain. Also, more studies are needed to evaluate the complete scenario and make definitive decisions.

Optical properties of low-pressure DC Ar plasma torch with N2–SiH4–B2H6 gas mixture injection for Si–B–N thin film deposition

Si–B–N ceramic hard films were prepared by injecting N2+SiH4+B2H6 reaction gas into an argon DC arc plasma jet at reduced pressure. XPS, FT-IR, SEM, and microhardness tester were used to characterize the samples, and the optical properties of Ar discharge plasma jet with and without reaction gas injection were studied by a multichannel high-resolution spectroscopy and a wide spectral range spectroscopy. It is found that the deposited films are mainly composed of Si, B, N and O. The film surface presents a dense structure with hundred-nanometer-sized clusters, and the hardness of sample is greatly enhanced. When the reaction gas is injected into the plasma jet, the emission of excited atoms in the background plasma is greatly reduced, and the growth rate of Si–B–N film shows a significant downward trend as the reaction gas injection ring or substrate holder is moved away from the torch nozzle. A slight enhancement of background plasma emission is observed near the substrate surface with increasing the distance between gas injection ring and torch nozzle, which indicates that the suppression effect of the reactive gas injection on the background plasma emission and the activation efficiency of the reaction gas are weakened, thereby reducing the deposition rate.