Coupled Plasma Atomic Emission Spectrometer Research Articles

Kinetic investigation of dry reforming of methane reaction over Ni–Rh/ZrO2–Al2O3 catalyst using Langmuir-Freundlich isotherm

The study involved conducting kinetic measurements for the dry reforming of methane (DRM) over a Ni–Rh/Al2O3 (85%)-ZrO2(15%) catalyst under a wide range of operating conditions (temperature: 500–900 °C, total flow rate of the inlet feed: 50–100 mL/min). The support material was prepared using the sol-gel method, followed by impregnation of Ni–Rh catalyst on the incipient wetness of the Al2O3–ZrO2 support. The calcined, reduced and spent samples were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), inductively coupled plasma atomic emission spectrometer (ICP-AES), N2 adsorption/desorption and CHNS analyzer, and tested for activity, yield and stability in DRM reaction. Furthermore, kinetic behavior of Ni–Rh/Al2O3–ZrO2 catalyst in DRM process was investigated by assuming DRM and reverse water-gas shift (RWGS) reactions take place on two kinds of different active sites. Experimental data were fitted using rate expressions based on the Langmuir-Freundlich (LF) isotherm for DRM and RWGS reactions. The activation energy for the DRM reaction was optimized at 43.62 kJ/mol, falling within the reported literature range of 24.73–108.9 kJ/mol. Statistical indices indicated that the kinetic model accurately predicted CO2 conversion compared to other responses, with an error of 12.054%. The computed and experimental trends for CH4 and CO2 conversions, H2 and Co yield in terms of temperature were similar with each other and the difference between the calculated and experimental trends was lower for conversions compared to yields.

Determination of rare earth elements in ferrocarbonatite using ICP-AES and ICP-MS

AbstractA method has been developed for the determination of Rare Earth Elements (REEs) in ferrocarbonatite using Inductively Coupled Plasma—Atomic Emission Spectrometer (ICP-AES) and Inductively Coupled Plasma—Mass Spectrometer (ICP-MS). The conventional dissolution procedures are tedious, with large measurement uncertainty and are thus not suitable for certified reference material (CRM) production and exploration of REEs. The described method involves leaching of sample using 3 M HCl followed by dissolution of residue (silica and REEs) by HF then determined REEs using ICP-AES and ICP-MS. The leaching step prevents formation of fluoride precipitates of matrix (Ca, Mg, Ba and Al). The method has been validated using CRMs.

L-cysteine mediated rapid separation of Hg2+ and MeHg+ by anion-exchange HPLC

Owing to the on-going emission of Hg into the global environment, new insight into their bioinorganic chemistry in mammals is urgently required to better understand their adverse health effects and analytical methods to quantify Hg2+ and MeHg+ in environmental samples are needed. Analytical separations can help to address both of these needs. While Hg2+ and MeHg+ have been most frequently separated by cation and reversed-phase (RP) HPLC, we here report on using anion-exchange (AEX) HPLC in conjunction with a flame atomic absorption spectrometer (FAAS) to observe the retention behavior of these mercury species in the pH range 5.0–8.0 using mobile phases comprised of 10 mM l-cysteine (Cys) in 100 mM phosphate buffer. The results obtained for pH 5.0 served as a starting point to develop a rapid HPLC separation for these mercurials. The addition of 5–20 % methanol (MeOH) to this mobile phase revealed that MeOH did not appreciably change the retention of Hg2+, but significantly reduced the retention of MeHg+. A 15 % MeOH-containing mobile phase offered the best compromise between achieving a rapid baseline separation in <400 s at affordable costs. To assess the suitability and robustness of the developed AEX-HPLC separation method for the analysis of environmental samples an inductively coupled plasma atomic emission spectrometer (ICP-AES) was employed as the mercury-specific detector. The developed AEX-HPLC-ICP-AES method allowed to achieve detection limits of 1.5 ppm for Hg2+ and 2.9 ppm for MeHg+ and was successfully applied to analyze wastewater that had been spiked with Hg2+ and MeHg+.

OBTAINING HUMATE-, NITROGEN AND MOLYBDENUM-CONTAINING LIQUID ORGANOMINERAL FERTILIZERS

The presence of humic substances (HS) and microelements in liquid organomineral fertilizers (LOMF) makes it possible to balance the mineral nutrition of plants and thereby increase the agricultural crops yield. The use of such fertilizers significantly increases the efficiency and reduces the costs of using mineral fertilizers. The aim of this work is to study the patterns of new types LOMF obtaining process, including macro- and microelements and physiologically active humic substances, and its composition and properties. Methods. Chemical analysis, inductively coupled plasma atomic emission spectrometer, infrared spectroscopy. Results and discussion. The processes of synthesis of LOMF through the interaction of sodium humate and ammonium heptamolybdate tetrahydrate were studied. Analysis of obtained results showed the same nature of the composition dependence and properties of the obtained LOMF on time. It was found that increasing the time from 10 to 120 min leads to an increase in the yield of humic acids (HAdaf) to 40.08%, the N content to 4.62% and Mo to 0.17%, the amount of COOH to 1.80 mg-eq/g and OHphen. groups – up to 0.71 mg-eq/g. It has been shown that with an increase in S:L ratio from 0.3:100 to 0.7:100, the HAdaf decreases to 36.97%, and the N and Mo contents increase, respectively, to 6.0 and 0.37%. Conclusion. The regularities of the time influence and S:L ratios on the composition and properties of LOMF samples have been established. It has been shown that an increase in time and S:L ratio contributes to an increase in the content of N and Mo, the carboxyl and phenolic hydroxyl groups. The changes in these parameters have different effects on the HAdaf. The presence of HS, N, Mo, COOH and OHphen groups in the resulting products allows them to be used in agriculture and for restoring soil fertility.

Interaction of carbonic anhydrase I released from red blood cells with human plasma in vitro.

Red blood cells (RBCs) constitute ∼50% of the bloodstream and represent an important target for environmental pollutants and bacterial/viral infections, which can result in their rupture. In addition, diseases such as sickle cell anaemia and paroxysmal nocturnal haemoglobinuria can also result in the rupture of RBCs, which can be potentially life-threatening. With regard to the release of cytosolic metalloproteins from RBCs into the blood-organ system, the biochemical fate of haemoglobin is rather well understood, while comparatively little is known about another highly abundant Zn-metalloprotein, carbonic anhydrase (CA I). To gain insight into the interaction of CA I with human blood plasma constituents, we have employed a metallomics tool comprised of size-exclusion chromatography (SEC) coupled online with an inductively coupled plasma atomic emission spectrometer (ICP-AES), which allows to simultaneously observe all Cu, Fe, and Zn-metalloproteins. After the addition of CA I to human blood plasma incubated at 37°C, the SEC-ICP-AES analysis using phosphate buffered saline (pH 7.4) after 5min, 1h, and 2h revealed that CA I eluted after all endogenous Zn-metalloproteins in the 30kDa range. Matrix-assisted laser desorption-time of flight mass spectrometry analysis of the collected Zn-peak confirmed that CA I eluted from the column intact. Our in vitro results suggest that CA I released from RBCs to plasma remains free and may be actively involved in health-relevant adverse processes that unfold at the bloodstream-endothelial interface, including atherosclerosis and vision loss.

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.

Solidification and Release Characteristics of Heavy Metals in Gypsum from Coal-Fired Power Plants

Heavy metals in flue gas desulfurization (FGD) gypsum from coal-fired power plants are at risk of releaching during the processes of stockpiling and resource utilization. In this study, the effects of organosulfur chelators dithiocarbamate (DTC) and trisodium trithiocyanate-15 (TMT-15) on the solidification characteristics of heavy metals in desulphurized gypsum under different mass fractions, pH values, water contents and reaction times were investigated. The chemical composition and morphology were analyzed by inductively coupled plasma atomic emission spectrometer (ICP-AES) and scanning electron microscope (SEM). The experiments showed that both DTC and TMT-15 were effective at stabilizing the heavy metals in the FGD gypsum, with more than a 50% curing effect for all the heavy metals except Pb. DTC showed a better stabilization for Pb, Hg, Cu, Zn, and Cr, and TMT-15 showed a better curing effect for Cd. The solidified gypsum had good heavy metal stability in low-water-content environments. Increasing the mass fraction, reaction time, and pH decreased the heavy metal leaching, and the mass fraction had the greatest effect on the total heavy metal leaching concentration, followed by the reaction time and pH value.

Environmental assessment of Heavy Metals in Sedi - ments of Tigris, Euphrates, Shatt Al-Arab rivers and northern west of Arabian Gulf.

The most prevalent environmental contaminants found in sediments that suggest the presence of effluents from both home and industrial sources are thought to be heavy metals. The aim of this study was to assess the accumulation of heavy metals at surface sediment samples that were collected in order to measure the amounts of Cu, Zn, Pb, Cd, and Fe., to re-evaluate the environmental conditions and concentration of the analyzed elements in the sediment to detect any pollution of heavy metals in the studied area by using contamination factors (CF), Enrichment Factor (EF) and geo accumulation index (I-geo). To ascertain the connection between the sediment’s total organic carbon (TOC) level and heavy metal pollution, measurements were taken in addition of it. Using the inductively coupled plasma atomic emission spectrometer, studies were conducted., The mean values of the element in the sediments ranged as: Cu (13.45 μg/g at location 2 to 32.44 μg/g at location 9), Zn (20.76 μg/g at location 1 to 42.49 μg/g at location 10), Pb (9.78 μg/g at location 2 to 30.04 μg/g at location 9 and 10), Cd (7.89 μg/g at location 2 to 18.72 μg/g at location 7) and Fe (459.89 μg/g at location 1 to 833.83 μg/g at location 7) dry weight. The geochemical results show that the distribution and concentration of the heavy metals in the studied sediments is within the average concentration given for the FAO/WHO reported, and the sediment of the studied area is still free from pollution, except Pb and Cd in some local areas, which shows higher concentrations than those reported for world sediments.

TYPOMORPHISM OF THE CHEMICAL COMPOSITION OF BIOGENIC CARBONATES WITHIN THE PRADNIPROV METHANE ANOMALY ON THE BLACK SEA SHELF

Problem Statement and Purpose. The aim of the article is to study the typomorphism of the chemical composition of biogenic calcium carbonates within methane anomalies formed by deep fluids in the bottom sediments of the Black Sea shelf. Gas chromatography was performed at the «Pradniprovska» study area. The results of the site`s bottom sediments analysis confirmed the content of pure methane and its homologues in the samples. Due to the presence of methane homologues, oxygen and carbon isotope analysis of the sediment shells was performed (it is known that the most stable information about the chemical composition of the mineral formation environment can be stored in biogenic carbonates of benthic organisms’ shells). The values obtained from the analysis had a small spread and did not show any visible variability. Data &amp; Methods. Data on the chemical composition of benthic organisms’ shells can be obtained using inductively coupled plasma atomic emission spectrometry. This method requires large samples by weight, so only the shells of the Mytilus mollusks were taken for the study due to their relatively large size. The gas-geochemical studies were based on the methodology of the NDL‑3 laboratory. The extracted gas was stored in glass tubes under a saturated saline solution, which ensured minimal losses from gas dissolution in the seal fluid, followed by studying it using a «Tsvet‑400» gas chromatograph. The separation of hydrocarbon gases was carried out on a chromatographic column filled with aluminum oxide. The detector is flame ionization. Calibration was carried out before the start of each cycle with calibration gas mixtures of standard composition. The spectrometric analysis was performed on a Thermo Scientific inductively coupled plasma atomic emission spectrometer with a CID or CMOS detector operating in the range of 167–820 nm. The method is based on the dissolution of substances in a mixture of nitric, hydrochloric and hydrofluoric acids at a temperature of at least 125 °C, followed by the determination of elements in solutions by inductively coupled plasma atomic emission. To consider matrix effects and improve measurement accuracy, calibration using internal standard lines is used. Results. The analysis of the obtained material allowed the author to draw the following conclusions: a) chemical elements in shells are unevenly distributed, and this unevenness is determined by two main reasons – the peculiarity of the formation of biogenic carbonate of shells and the ability of the carbonate to isomorphically capture a number of elements from the mineral-forming environment; b) according to the quantitative characteristics, three groups of elements can be distinguished: macroelements, mesoelements and trace elements. The first group of elements (macroelements) includes Na, S, Mg, Sr, Fe, Si, Mn, P, K. Among them, one can clearly distinguish elements that are isomorphically included in the structure of calcite or aragonite (Na, Mg, Sr, Fe, Mn, K) and elements captured as non-structural impurities in the agglutination process during the growth of biogenic carbonate (Si, S and P). The second group (mesoelements) includes Ba, Al, As, Zn, Cu, Ti, among which two groups can also be distinguished. One is associated with the formation of sulfide minerals paragenetic to biogenic calcite (As, Zn, Cu), and the other with agglutination of clay minerals in sediments (Al, Ti), or a feature of isomorphism in the biogenic formation of calcium carbonate (Ba). The third group (trace elements) is associated with elements of low content and uneven distribution (Ni, Mo, Pb, Se). The main group here is Ni, Cr, Co, V. These groups, taking into account the fact that they were found in the areas of penetration of deep-sea fluids into the sedimentary strata, allows to consider them as typomorphic signs of biogenic carbonate formation in the areas of fluid influence, and, consequently, as a search sign of such areas on the Black Sea shelf.

Optimization of the Method for Spectrofluorimetric Determination of Aluminum Impurities in Substances

Introduction. Evaluation of the content of impurities is the most important step in confirming the safety and efficacy in the quality control of the medicinal product. Aluminum, being an acceptable impurity in a number of pharmaceutical substances, can adversely affect the human body, as a result of which its content is normalized. The admixture of aluminum in the State Pharmacopoeia of the Russian Federation XV is determined by the spectrofluorimetric method using the ligand – 8-hydroxyquinoline in chloroform. In the present work, it is proposed to replace 8-hydroxyquinoline with the more accessible rutin, which also forms fluorescent complexes with metals. This approach involves the exclusion of the stage of extraction of the aluminum complex into chloroform from sample preparation, which improves the accuracy of the technique, and the replacement of chloroform has a positive effect on safety.Aim. To create an alternative approach for the spectrofluorimetric determination of aluminum impurities using rutin and "potassium chloride" as an active pharmaceutical ingredient.Materials and methods. The following substances and reagents were used as research materials: CRS of aluminum ion 1 mg/ml (LLC "EKROSHIM", Russia), CRS of iron ion (II) 1 mg/ml (LLC "EKROSHIM", Russia), CRS of zinc ion 1 mg/ml (LLC "EKROSHIM", Russia), CRS of lead-ion 1 mg/ml (LLC "EKROSHIM", Russia), CRS nickel-ion 1 mg/ml (LLC "EKROSHIM", Russia), CRS copper-ion 1 mg/ml (LLC "EKROSHIM", Russia), chromium (III) cation standard 1 mg/ml (imp., Sigma-Aldrich, USA) rutin (imp., Sichuan Guangsong Pharmaceutical Co., Ltd., China), ammonium acetic acid (imp., Molekula GmbH, Germany), glacial acetic acid (chemically pure, JSC "Base No. 1 Himreaktivov", Russia), potassium chloride (pharmaceutical substance, LLC "MZHR", Russia). The spectrofluorimetric study was carried out on an FL 6500 instrument (PerkinElmer Inc., USA). The aluminum impurity content was also evaluated using an Optima 8000 inductively coupled plasma atomic emission spectrometer (ICP AES) (PerkinElmer Inc., USA) and a Multi-Element Solution standard sample (PerkinElmer Inc., USA).Results and discussion. The approach given in the article eliminates the use of 8-hydroxyquinoline in chloroform and replaces it with rutin in 70 % ethyl alcohol. The aluminum-rutin complex has an excitation wavelength at 445 nm and an emission wavelength at 565 nm. The proposed method was tested on the substance "Potassium chloride" to assess the indicator "Aluminum", the content of which should not exceed 0.0001 %. Method validation was carried out according to three parameters "Specificity", "Linearity" and "Limit of detection". Comparison of the data obtained was carried out using atomic emission spectroscopy, during which the relevance of the technique was proved.Conclusion. An ergonomic approach has been developed for the spectrofluorimetric determination of aluminum impurities using rutin with approbation on the substance "Potassium chloride". The results obtained during the experiment were confirmed by the ICP AES method.

N-Acetylcysteine Displaces Glutathionyl-Moieties from Hg2+ and MeHg+ to Form More Hydrophobic Complexes at Near-Physiological Conditions.

The anthropogenic release of Hg is associated with an increased human exposure risk. Since Hg2+ and MeHg+ have a high affinity for thiols, their interaction with L-glutathione (GSH) within mammalian cells is fundamentally involved in their toxicological chemistry and excretion. To gain insight into the interaction of these mercurials with multiple small molecular weight thiols, we have investigated their competitive interactions with GSH and N-acetylcysteine (NAC) at near-physiological conditions, using a liquid chromatographic approach. This approach involved the injection of each mercurial onto a reversed-phase (RP)-HPLC column (37 °C) using a PBS buffer mobile phase containing 5.0 mM GSH to simulate cytosolic conditions with Hg being detected in the column effluent by an inductively coupled plasma atomic emission spectrometer (ICP-AES). When the 5.0 mM GSH mobile phase was amended with up to 10 mM NAC, gradually increasing retention times of both mercurials were observed. To explain this behavior, the experiment with 5.0 mM NAC and 5.0 mM GSH was replicated using 50 mM Tris buffer (pH 7.4), and the Hg-containing fractions were analyzed by electrospray ionization mass spectrometry. The results revealed the presence of Hg(GS)(NAC) and Hg(NAC)2 for Hg2+ and MeHg(GS) and MeHg(NAC) for MeHg+, which suggests that the coordination/displacement of GS-moieties from each mercurial by the more hydrophobic NAC can explain their retention behavior. Since the biotransformations of both mercurials were observed at near-physiological conditions, they are of toxicological relevance as they provide a biomolecular explanation for some results that were obtained when animals were administered with each mercurial and NAC.

Evaluation of metal pollution related to human health risk in freshwater snail Viviparus contectus (Millet, 1813) as a potential bioindicator species in Lake Habitat (Turkey).

Freshwater mollusks are employed as bioindicators for the assessment of water quality in biomonitoring studies since the water quality of natural resources is crucial for humans. The freshwater snail species known as Viviparus contectus (Viviparidae: Gastropoda) is one that people eat. Here, the levels of heavy metals (Cd, Cr, Pb, As, Zn, and Cu) in water and V. contectus samples were determined. An Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES, Spectro Arcos, vertical plasma) was used for the analysing the heavy metal concentrations in water and freshwater snail samples. The results of the current investigation demonstrated that freshwater snails accumulated metals in their water and soft tissues in the following orders: Pb > Cr = Zn = Cu = Cd = As and Zn > Cu > Pb > Cd > As = Cr. Autumn was the time of year when higher amounts of heavy metals (As, Cr, Cu, Zn, and Hg) were found. Pb content in the freshwater snail samples was strongly impacted by seasonal fluctuations (P 0.05). For adults, the EDI (estimated daily intake) values were lower than the TDI (tolerable daily intake) values, and the HI (hazard index) values were below 1. Freshwater snail samples had Zn and Pb levels that were over the FAO/WHO, Turkish Food Codex, JECFA, and EC limit values. Except for Pb, the water study shows mean metal concentrations below the USEPA, Turkish Pollution Control Regulation, and World Health Organisation maximum allowed levels. Aquatic ecosystems were negatively impacted by anthropogenic activities overall, and this study can provide a helpful data set for investigations on metallic contamination in water bodies and biomonitoring in freshwater ecosystems.

More Effective Mobilization of Hg2+ from Human Serum Albumin Compared to Cd2+ by L-Cysteine at Near-Physiological Conditions.

Although chronic low-level exposure to Hg2+ and Cd2+ causes human nephrotoxicity, the bioinorganic processes that deliver them to their target organs are poorly understood. Since the plasma protein human serum albumin (HSA) has distinct binding sites for these metal ions, we wanted to gain insight into these translocation processes and have employed size-exclusion chromatography coupled on-line to an inductively coupled plasma atomic emission spectrometer using phosphate-buffered saline mobile phases. When HSA 'labeled' with Hg2+ and Cd2+ (1:0.1:0.1) using 300 μM of L-methionine was analyzed, the co-elution of a single C, S, Cd, and Hg peak was observed, which implied the intact bis-metalated HSA complex. Since human plasma contains small molecular weight thiols and sulfur-containing metabolites, we analyzed the bis-metalated HSA complex with mobile phases containing 50-200 µM of L-cysteine (Cys), D,L-homocysteine (hCys), or glutathione (GSH), which provided insight into the comparative mobilization of each metal from their respective binding sites on HSA. Interestingly, 50 µM Cys, hCys, or GSH mobilized Hg2+ from its HSA binding site but only partially mobilized Cd2+ from its binding site. Since these findings were obtained at conditions simulating near-physiological conditions of plasma, they provide a feasible explanation for the higher 'mobility' of Hg2+ and its concomitant interaction with mammalian target organs compared to Cd2+. Furthermore, 50 µM Cys resulted in the co-elution of similar-sized Hg and Cd species, which provides a biomolecular explanation for the nephrotoxicity of Hg2+ and Cd2+.

Phase separation of alkaline earth fluorosilicate glass: A strategy to suppress fluoride evaporation

Fluorosilicate glasses are widely applied as optical and luminescent materials to host a variety of lanthanides. However, fluorides evaporation causes notable difference between the actual composition and the nominal composition of fluorosilicate glass. In this work, a series of SiO2 - Al2O3 - MF2 (M = Ca, Sr, Ba) glasses are fabricated, and quantitative element analysis is performed to determine the actual composition of the fluorosilicate glasses through an inductively coupled plasma atomic emission spectrometer (ICP-AES) and a gas chromatography analysis. A series of molecular dynamics (MD) simulations are carried out to study the glass network microstructures. The phase separation with silicate and fluoride phases is clearly observed in the MD simulated structures and agrees well with the observed self-crystallization of fluorides in the experiments. SiF4 as well as CaF2 / SrF2 / BaF2 are confirmed as the major evaporated substances from the glass melts. The phase separation may well inhibit the evaporation of SiF4 through partitioning Si4+ and F− ions into silicate phase and fluoride phase, respectively. The phase separation may enrich the alkaline earth cations into fluoride phase thus aggravate the evaporated loss of alkaline earth elements. This study is then help to understand the mechanism of fluoride evaporation from glass melts, and quantitatively predict actual composition of the fluorosilicate glasses.

Combined steam and dry reforming of methanol over Ni-M/Ce–Al2O3 (M=Fe, Cu, and Zn) catalysts to syngas formation

In the present work, the influences of different transition metals (Fe, Cu, and Zn) addition to Ni/Ce–Al2O3 catalyst on combined steam and dry reforming of methanol (CSDRM) reaction were evaluated in the temperature range of 500 ºC-900 °C, to achieve the higher conversion and H2 yield following by minimum coke formation on the catalyst surface. The fresh and spent catalysts were characterized via X-ray diffraction (XRD), thermal gravimetric analysis (TGA), inductively coupled plasma atomic emission spectrometer (ICP-AES), temperature programmed oxidation (TPO), N2 adsorption/desorption and temperature programmed reduction (TPR). Their results presented that the addition of these transition metals had a little effect on the crystallinity, surface area, pore volume and mean pore size. However, thermal stability, coke deposition coke amount, reducibility and catalytic activity were improved. The methanol conversion was approximately fixed up to 50 h initial on stream with no obvious deactivation for Ni/Ce–Al2O3 catalyst, while this time was 55 h for the modified catalyst with transition metals (Cu, Fe, and Zn). The maximum methanol and CO2 conversions and anti-coke deposition ability were obtained from Ni–Zn/Ce–Al2O3 which was remarkably related to synergism between Ni and Zn, also the larger reducibility. However, the maximum value of H2 yield was 85.2% at 900 °C over Ni–Cu/Ce–Al2O3 catalyst. Ni–Zn/Ce–Al2O3 catalyst in the CSDRM reaction produced syngas with an H2/CO ratio of 2.06, suggesting to a suitable feed for Fischer-Tropsch synthesis.

Benthic foraminifera as bioindicators for the heavy metals in the severely polluted Hurghada Bay, Red Sea coast, Egypt

Twenty-nine sediment samples were collected from the Hurghada Bay, a heavily polluted bay on the Red Sea of Egypt, to inspect the environmental quality status and anthropogenic consequences on benthic foraminifera. Some foraminiferal species showed deformations in their apertures and coiling directions as a response to environmental stresses. In addition, the FoRAM index, an index used for evaluating the growth of coral reefs, indicated a hazard in the proximity of nearshore stations. To elucidate the relationships between the biological response and chemistry of sediments, eight heavy metals concentrations (Cu, Cd, Zn, Pb, As, Cr, Ni, and Mn) were analyzed using inductively coupled plasma–atomic emission spectrometers (ICP-AES). Interestingly, two groups of benthic foraminiferal associations were illustrated using multivariate statistical analyses. Group I have extremely high heavy metal concentrations, an enriched total organic matter (TOM)%, high deformation percentages, and mud content. Moreover, it is dominated by Ammonia tepida which is regarded as an opportunistic species. Group II includes low to moderately polluted stations, highly enriched living foraminiferal assemblages, and is dominated by the sensitive rotaliids Neorotalia calcar and Amphistegina lobifera. Alternatively, four geochemical indices, EF, CF, Igeo, and PLI, are used to assess the contamination level that shown ominous spots for the nearshore stations of the Hurghada Bay. The pollution indices (HQ and HI) were also conducted to evaluate the risks of carcinogenic heavy metals on human health. Our findings demonstrated that ingestion and dermal exposure have greater carcinogenic hazards for adults and children than inhalation. The lifetime carcinogenic risk (LCR) is significantly higher than the permissible limit and follows this order: Pb > As > Cr > Cd > Ni. To that end, developing strategies to lessen the negative impact of pollution on human health and/or the Red Sea’s biodiversity is an inevitable issue in the present day and future.

Discrimination of Free-Range and Caged Eggs by Chemometrics Analysis of the Elemental Profiles of Eggshell.

As one of the foods commonly eaten all over the world, eggs have attracted more and more attention for their quality and price. A method based on elemental profiles and chemometrics to discriminate between free-range and caged eggs was established. Free-range (n1 = 127) and caged (n2 = 122) eggs were collected from different producing areas in China. The content of 16 elements (Zn, Pb, Cd, Co, Ni, Fe, Mn, Cr, Mg, Cu, Se, Ca, Al, Sr, Na, and K) in the eggshell was determined using a inductively coupled plasma atomic emission spectrometer (ICP-AES). Outlier diagnosis is performed by robust Stahel-Donoho estimation (SDE) and the Kennard and Stone (K-S) algorithm for training and test set partitioning. Partial least squares discriminant analysis (PLS-DA) and least squares support vector machine (LS-SVM) were used for classification of the two types of eggs. As a result, Cd, Mn, Mg, Se, and K make an important contribution to the classification of free-range and caged eggs. By combining column-wise and row-wise rescaling of the elemental data, the sensitivity, specificity, and accuracy were 91.9%, 91.1%, and 92.7% for PLS-DA, while the results of LS-SVM were 95.3%, 95.6%, and 95.1%, respectively. The result indicates that chemometrics analysis of the elemental profiles of eggshells could provide a useful and effective method to discriminate between free-range and caged eggs.

Assessment of heavy metals in exchangeable sediments samples from Tigris – Euphrates and Shatt al-Arab rivers

The object of this study is the concentrations of heavy metals (cadmium, copper, iron, lead, manganese, nickel, and zinc) in sediment samples taken from the Tigris, Euphrates, and Shatt al-Arab rivers during the autumn 2021 to summer 2022. According to the analyses performed using the inductively coupled plasma atomic emission spectrometer, showed the seasonal average of heavy metal concentrations ranges between the lowest value (7.46 µg/g) for nickel in summer and the highest value (785.08 µg/g) for iron during winter in exchangeable phase. Measurements were made of variables that influenced how heavy metals were distributed in the sediments, as shown by (total organic carbon, and grain size analysis) which revealed a relationship between the concentrations of heavy metals in the sediments and these variables, suggesting that pollution from various human activities – the main cause of the high concentrations of some heavy elements in the study area's sediments above the global natural rates. Geo Accumulation Index (I-geo) for heavy elements in the sediments was also determined, and it showed that the yearly rate of the concentrations of the metals varied between the lowest value (–6.912) of Iron and the maximum value (6.767) for cadmium. Additionally, it was determined the enrichment coefficient (EF) for the heavy elements in the sediments, where the annual rate of the metals ranged between the lowest value (3.23) for manganese and the highest value (10406.58) for cadmium, and was accounted the contamination factor (CF) for the heavy metals in the sediments, where the annual average of the metals ranged between the lowest value (0.012) for iron and the highest value (163.4) for cadmium. If our findings are compared to those of previous study, this will be lies within previous data. This is very important data it can be used as a baseline for coming study, and also used as a reference in other countries.

A novel borate-based 45S5 Bioglass®: In vitro assessment in phosphate-buffered saline solution

A novel borate-based 45S5 Bioglass® has been formulated and synthesized using the melt-quenching method. The in vitro assessment was performed to determine the bioactivity of the glasses using phosphate buffer saline (PBS) as an immersion solution. The pH measurement is performed using a pH meter, while ion dissolution is quantified using Inductively coupled plasma atomic emission spectrometer (ICP-OES). The immersion of borate-containing glass exhibits pH closes to human body fluid (≈7.40). The (Ca/P) atomic ratio was calculated and its value increased (1.7–4.0) along with borate contents, indicating improved bioactivity. The alteration of glass structure after the in vitro test is inspected using attenuated total reflectance sensor–Fourier transform infrared spectrophotometer (ATR-FTIR) and Raman spectrometer. The 45S5 Bioglass that comprised 40–80% of borate showed the appearance of HPO42− a vibration band which specifies the growth of hydroxyapatite (HPA) after the in vitro test. Relative to 45S5 Bioglass®, glass labeled 0.4B2O3 displayed the highest potential of HPA growth (248%), while dissolving BO3 and BO4 units at 57.36 and 8.48%, respectively. The new formulation technique offers an alternative path to control the degradation behavior of 45S5 Bioglass® glass by modifying the ratio of borate constituent. The prepared glass may find its potential in soft-bone tissue engineering applications.

Experimental Investigation on Influence of Acidic Dry-Wet Cycles on Karst Limestone Deterioration and Damage

This study is aimed at the problem of limestone deterioration and damage caused by the combination of acid rain and the dry-wet cycle in Guilin. Samples of limestone were taken to study the influence of acidic dry-wet cycles on limestone deterioration and damage. This was accomplished by performing nuclear magnetic resonance (NMR) measurements and inductively coupled plasma atomic emission spectrometer measurements on the limestone samples. The study found that with an increase in the number of cycles, the T 2 curve of the rock continuously shifts to the right, but the range of movement still decreases with pH increasing values. The T 2 spectrum area, rock porosity, porosity deterioration, mass loss rate, and water absorption rate all increase with an increase in the number of cycles, but the growth rate continues to decrease, and the increase is negatively correlated with pH. After the dry-wet cycles, the mass concentration of each element in the beaker is Ca, Mg, and Fe in order from high to low, and the mass concentration of each main element in the reaction solution increases with the increase in the number of acidic dry-wet cycles.