Inductively Coupled Plasma Mass Spectrometer Research Articles

Safety and quality aspects of whole and skimmed milk powders.

Nowadays, dried milk products are highly traded and consumed all over the world, so we aimed in this study to evaluate to what extent whole and skim milk powders are safe and comply with Egyptian standards. Eighty samples of dried milk (50 whole milk powder and 30 skim milk powder) were gathered from several retailers and supermarkets for evaluation of their differing quality and safety parameters. The most frequent off-flavors recovered from whole milk powder samples were cooked ones and, in the case of skim milk powder samples, flat ones. Five samples of whole milk powder were of fair quality and three samples of poor quality, according to the sensory evaluation. The compositional parameters, moisture, %, fat, %, protein, %, and acidity, %, were measured as mean values of 3.90 ±0.15, 26.90 ±0.19, 25.53 ±0.27, and 0.99 ±0.03% in the examined whole milk powder samples and 3.77 ±0.08, 1.11 ±0.05, 34.62 ±0.29, and 1.22 ±0.03% in the examined skimmed milk powder samples, respectively. These results were within the range of component requirements set by the Egyptian Standard (2014; ES: 1780/2014) for dried milk products. Also, the microbiological safety of the milk powder samples was analyzed by assessment of the total viable count, total yeast and mold count, Coliforms count, Enterobacteriaceae, E. coli, C. sakazakii, Staphylococcus aureus, Salmonella, and Listeria monocytogenes. Staphylococcus aureus was the most prevalent isolate (36.00% and 6.67%) followed by Enterobacteriaceae (20.00% and 3.33%), of whole and skim milk powder, respectively. Enterobacteriaceae isolates included Enterobacter cloacae ssp. Cloacae, and Pantoea spp., which were specified by traditional biochemical tests and Vitek2 system. All Enterobacteriaceae isolated spp. were resistant to cephalothin, neomycin, tobramycin and colistin sulphate, and sensitive to chloramphenicol, gentamycin and nalidixic acid. E. coli, C. sakazakii, Salmonella, and Listeria monocytogenes couldn't be isolated from all the tested samples. By using Inductive Coupled Plasma - Mass Spectrometer (ICP-MS), we could measure lead and mercury as mean values of 0.243 ±0.069 and 0.261 ±0.052 mg/kg for whole milk powder samples at a percentage of 68.00 and 34.00%, while for the skim milk powder samples they were 0.150 ±0.037, and 0.347 ±0.110 mg/kg at a percentage of 66.67 and 40.00%, respectively. Finally, thirty-four whole milk powder and twelve skimmed milk powder samples didn't comply with Egyptian standards, so it is necessary for authorities to put more attention on this and regular monitor it.

Robust Potassium Isotopic Analysis of Geological and Biological Samples via Multicollector ICP-Mass Spectrometry Using the "Extra-High Resolution Mode".

Potassium isotopic analysis is arousing increasing interest, not only in geochemistry, but also in biomedicine. However, real-life applications are still hindered by the lack of robustness of the methods used. In this work, a novel and robust method for high-precision K isotopic analysis of geological and biological samples was developed, based on the use of a multicollector ICP-mass spectrometer providing a mass resolving power of 15,000 (extra-high resolution mode, XHR). After evaluation of different measurement conditions, i.e., hot vs cold plasma conditions, standard-type vs jet-type sampling cone, and high resolution (HR) vs XHR, a combination of hot plasma conditions, use of the high-transmission jet-type sampling cone, and the XHR mode allowed for high-precision and interference-free K isotopic analysis. Potassium signal monitoring was performed in the ArH+ interference-free 0.006-0.007 amu wide peak shoulder using the XHR mode. The within-run, short-term external, and long-term external precisions for the δ41K value were 0.02‰ (2se, N = 50), 0.03‰ (2SD, N = 7), and 0.06‰ (2SD, N = 163), respectively. A two-stage chromatographic procedure was developed for the isolation of K from both geological and biological samples, and potential matrix effects affecting the K isotope ratio were systematically evaluated. The method was first applied to geological reference materials (RMs) for validation purposes, and the K isotope ratio results were in good agreement with those previously reported. Subsequently, a series of biological RMs, including serum, whole blood, cerebrospinal fluid, bovine muscle, and lobster hepatopancreas, were characterized for their K isotopic composition.

Urinary iodine and sodium concentration and thyroid status in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

ObjectivesTo evaluate urinary iodine concentration (UIC) in civil servants aged 35-74 years of the Brazilian Study of Adults Health (ELSA-Brasil) to analyze its relationship with sociodemographic, clinical risk factors, lifestyle, urinary Na and thyroid status. DesignCross-sectional study in six Brazilian cities. MethodsThis analysis included 792 participants with information about urinary iodine concentration (UIC). Thyroid status was defined by serum levels of TSH/FT4 and the current use of antithyroid drugs for treatment of overt hyperthyroidism or levothyroxine to treat overt hypothyroidism. The determination of UIC was carried out with an inductively coupled plasma mass spectrometer (ICP-MS) and was expressed as median with Interquartile Range (IQR). ResultsIn 792 participants, thereof 52% women, mean age was 51.9 (9.0) years. The median UIC was 219 (IQR, 166-291) for all persons studied, thereof 211 (IQR, 157-276) for women and 231 (IQR, 178-304) for men. According to the WHO classification, for all persons studied, 60% had more than adequate iodine-supply (UIC ≥200 μg/L), 37% were adequately supplied (UIC 100-199 μg/L) and <3% had a deficient iodine status (<100 μg/L). In the 35-44-year age strata, which includes women of childbearing age, 23.2% of women presented less than 150 μg/L of UIC. No differences in UIC were detected according to thyroid status. (P = 0.39) The correlation between Ur-Na and UIC showed a Spearman coefficient of 0.52 (P < 0.0001) and it was also found an association of Ur-Na with UIC: Beta of 1.76 (95% Confidence Interval (95% CI): 1.01 to 2.51. The urinary Na concentration showed a synergy with the UIC, that means medians of 57, 72, 107 and 141 mmol Na/L urine (P < 0.001) in the groups with the four UIC classes according to the WHO grading mentioned above. The very low Na content in the persons exhibiting <100 μg/L UIC seems to reflect also a higher urine volume due to the frequent use of diuretics. The strong relationship between the urinary Na concentration and the UIC points to a dependence of the UIC on the individual consumption of iodized salt, which should be more considered in future studies. The strong relationship between the urinary Na concentration and the UIC points to a dependence of the UIC on the individual consumption of iodized salt, which should be more considered in future studies. ConclusionsEuthyroid persons were dominating by more than four fifths and no significant association was found between UIC and thyroid status. Although most of the persons studied present more than adequate iodine intake it was observed that nearly a quarter of women in childbearing age are iodine deficient.

Trace elements concentration in soil and plant within the vicinity of abandoned tanning sites in Bangladesh: an integrated chemometric approach for health risk assessment

An effective toxicological assessment of soil-metal bioavailability and plant translocation processes is needed in view of the growing negative impact of trace element pollution on the terrestrial environment and human health. This study was conducted to assess the toxicological processes that regulate the plants’ trace element absorption into their tissues, the suitability for human use, the potential sources of trace elements, and the risk to human health, using an integrated research methodology. Soils and sweet potato plants were collected from agricultural fields near the tannery waste disposal sites of Dhaka City, Bangladesh and inductively coupled plasma mass spectrometers (ICP-MS) were used to analyze the essential and toxic elements. The mean concentrations of total elements in soil followed the descending order of Fe > Zn > Mn > Cr > Ni > Pb > Cu > As > Cd and in plant Fe > Zn > Cu > Cr > Ni > Mn > Pb > As > Cd. In the edible tissues of sweet potato, the concentrations of essential and toxic elements exceeded the maximum permissible levels, indicating not safe for human consumption. The translocation factor (TF) revealed that studied elements are more accumulated in the leaves than tubers. The enrichment factor revealed minimal to very high enrichment of essential and toxic elements in the plant parts while the contamination factor showed low to very high contamination. Considering the health risk of toxic elements from plant samples, As and Pb caused non-cancer and cancer risk on human health. However, the present results suggested that regular monitoring of these essential and toxic elements in soil and plants as well as other food materials around the abandoned tannery waste disposal sites are necessary to prevent excessive build-up of these elements in the food chain.

Online Stability Investigations of Platinum Electrodes in Nonaqueous Media

In the process of developing novel electrocatalysts, the focus mainly lies on finding highly active and selective materials. The stability of electrodes is often underestimated, even though a poor stability is inextricably related to economic losses. Fundamental understanding of electrode dissolution processes in nonaqueous media is not only crucial for applications like nonaqueous battery systems, sensors, capacitors but also for organic electrosynthesis. The reasons for electrode degradation are among others anodic dissolution, cathodic dissolution or cathodic corrosion. Enhanced knowledge of dissolution mechanisms, especially understanding the influence of factors like composition or structure of electrodes, electrolytes and temperature, is important to optimize the operation conditions of reactors, and with that limit electrode degradation and increase the lifetime of devices and improve processes.Coupling electrochemical measurements with an inductively coupled plasma mass spectrometer (ICP-MS), allows online stability studies and gives valuable insights into degradation mechanisms of different electrodes and catalyst materials, which are relevant in various applications. We have developed an electroanalytical flow cell (EFC) coupled to an ICP-MS, which is suitable for the use in aggressive nonaqueous electrolytes. Furthermore, the EFC is operated in an argon filled glovebox, which allows otherwise unattainably strict control of experimental conditions, like the water content of electrolytes [1,2].In order to demonstrate the capabilities of this novel method, dissolution of platinum as an ideal model system will be depicted first: this metal has excellent electrocatalytic activity and somewhat falsely supposed inertness. It is widely used in various fields of applications and its behavior in aqueous media is fairly well known. New aspects of its stability in different nonaqueous electrolytes are unveiled together with dependences on the chemical properties of the solvents and the conducting salts. While the dissolution behavior of completely water-free protic and aprotic electrolytes is very similar, the dissolution behavior changes markedly upon temperature variation or in presence of trace amounts of water.Different platinum dissolution profiles in several nonaqueous electrolytes will be discussed and dissolution mechanisms will be proposed, based on studies with changing water content. The dissolution of this electrode material has been followed during a running electrosynthesis. The correlation of possible reaction intermediates with the stability will be illustrated for a Kolbe electrolysis.Literature:[1] J. Ranninger, et al., Electrochem. Comm., 2020, 114 (106702), [2] J. Ranninger, et al., J. Electrochem. Soc., 2020, 167 (121507)

Post Chemical Mechanical Planarization (CMP) Cleaning Using Hydrogen Dissolved Water

In current semiconductor manufacturing process, especially chemical mechanical manufacturing (CMP) process, ceria nanoparticle dispersed slurry is well known consumable for various CMP processes such as shallow trench isolation (STI), inter layer dielectric (ILD) CMP process, and etc. After CMP process, the ceria nanoparticles which are the sources of defects must be removed surely before performing the other processes. Typically, Standard clean solutions such as SC-1, SC-2, and etc. are applied to the post CMP cleaning process. These cleaning solutions are still effective to remove the residual ceria particles but there are several disadvantages such as quite harmful for health and need of additional treatments for wastewater. In this study, cleaning efficiency of the H2 gas dissolved water was evaluated comparing with DIW and other standard cleaning solutions. 4x4 cm2 of silicon dioxide film wafers were polished supplying ceria slurry and then immersed into the cleaning solutions such as DIW, standard clean solutions, and H2 dissolved water, respectively. Finally, we quantitively analyzed the residual cerium dioxide on the cleaned wafer surface by using inductively coupled plasma mass spectrometer (ICP-MS). H2 dissolved water removed residual ceria nano particles from the silicon dioxide film considerably comparing to DIW. Figure 1. show residual ceria ion concentration after cleaning process and cleaning efficiency calculated. Figure 1

Gas Diffusion Electrode Half Cells – a Powerful Tool for Fuel Cell Electrocatalyst Evaluation in Relevant Conditions

In aqueous rotating disk electrode (RDE) measurements, advanced catalyst materials show tremendous performance improvements in comparison to commercial Pt/C catalysts towards oxygen reduction reaction (ORR). However, these promising improvements cannot (yet) be transferred to realistic membrane electrode assembly (MEA). [1] These discrepancies can be explained by non-ideal catalyst layer composition, leading to mass transport limitations of either oxygen (which is transported through the pores) or protons (via the ionomer) to the active centers of the catalyst material. Mass transport phenomena in real catalyst layers are still under debate and hold huge potential to significantly improve catalyst performance.However, mass transport in realistic fuel cell catalyst layers cannot be assessed with RDE experiments, as they are limited to low current densities and idealized catalyst layers on solid substrate. Therefore, MEA experiments are usually employed to evaluate those phenomena. Yet, those investigations are time consuming, expensive (large quantities of catalyst needed, extended test equipment) and do not allow segregated investigation of either cathode or anode catalyst layer. Furthermore, comparison of different MEA studies can be challenging due to varying operating conditions. Therefore, techniques combining the advantages of RDE, namely simplicity and comparability, with the realistic operating ranges of MEA are urgently required to retrieve the potential of catalyst layer optimization.In this presentation half-cells using gas diffusion electrodes (GDE) are proposed as a new powerful experimental tool to enable high mass transport catalyst screening in relevant potential ranges and realistic electrode structures.On the example of a Pt loading study we show, that current densities of up to 2 A/cm² can be achieved [2]. In contrary to other formerly used methods [3], it is thereby possible to overcome mass transport limitations at relevant fuel cell operating potentials. Additionally, we demonstrate good compliance with MEA experiments, proving the method´s suitability for catalyst evaluation in realistic fuel cell potential ranges.Besides activity, also stability of the electrocatalyst is affected significantly by the catalyst layer structure. We present here a novel method, where a GDE half-cell is coupled to an inductively coupled plasma mass spectrometer (ICP-MS) to gain deeper insights into dissolution of electrocatalysts in realistic electrode structures [4]. With this unique online tool, we could measure Pt dissolution in realistic catalyst layers for the first time reported in literature. We show, how mass transport of dissolved Pt species influences net Pt dissolution and how Pt dissolution can also be detected through Nafion membranes. Besides that, also the mobility of Pt-ions through Nafion membranes is further investigated. Literature [1] Ly, A., et al. J. Power Sources, 2020. 478: 228516[2] Ehelebe, K., et al., J. Electrochem. Soc., 2019. 166(16): F1259-F1268,[3] Inaba, M., et al., Energy Environm. Sci., 2018. 11(4): 988-994,[4] Ehelebe, K. et al. submitted Figure 1

Study of Heavy Metals Pollution and Vitellogenin Levels in Brown Trout (Salmo trutta trutta) Wild Fish Populations

The objectives of this research were, first, to determine the concentrations of certain heavy metals in the edible tissue of wild brown trout (Salmo trutta trutta) from two different rivers located in the Abruzzi region (Italy), and then, to investigate the levels of variation in vitellogenin (VTG) associated with the presence of metalloestrogens. VTG is an effective indicator for endocrine disturbance, and an increase in the vitellogenin levels in male fish is widely employed as a biomarker of estrogenic contamination in the aquatic environment. The muscles of the trout were analyzed for As, Cd, Co, Cr, Ni, Pb, Al, and Zn using an inductively coupled plasma-mass spectrometer (ICP-MS), and Hg was measured using a direct mercury analyzer (DMA-80). The calculated values of the condition factor confirmed a healthy status for this species, indicating that the aquatic habit in both rivers is suitable for brown trout life. No significant difference in the concentrations of each metal were reported between the trout from the two rivers, and no significant difference for VTG levels were found between male and female fish. It is interesting to note the high concentrations of Al/Zn, while the Pb, Cd, and Hg concentrations in all of the samples were lower than those established by the European Commission.

Superior formic acid electrooxidation activity on carbon nanotube‐supported binary Pd nanocatalysts prepared via sequential sodium borohydride reduction technique

In this study, multiwalled carbon nanotube (MWCNT)‐supported M (Pd, Ni, Co, Mn, V, Zn)/MWCNT monometallic and M (Ni, Co, Zn, V, Ag, Mn)@(Pd/MWCNT) binary nanocatalysts were investigated to examine the effect of second metal promotion to Pd on formic acid electrooxidation (FAEO) activity. The sequential sodium borohydride (SBH) reduction technique was used for the preparation of nanocatalysts. For binary nanocatalysts, first of all, the monometallic Pd/MWCNT nanocatalyst was prepared. Then, second metal precursors (NiCI2, CoCl2, ZnCI2, V2O5, AgNO3, and MnCI2) were added to Pd/MWCNT and further reduced with NaBH4. After filtration and drying, binary nanocatalysts M@(Pd/MWCNT) were obtained. X‐ray diffractometry (XRD), inductively coupled plasma mass spectrometer (ICP‐MS), transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS) methods were used to characterize the obtained nanocatalysts. In addition, cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) measurements were utilized to examine the electrochemical activities of the nanocatalysts for FAEO. The results indicate that Ni@(Pd/MWCNT) nanocatalyst is better than the other nanocatalysts with 10.75‐mA cm−2 specific and 2924.48‐mA mg−1 Pd mass activity. Furthermore, Ni@(Pd/MWCNT) nanocatalyst has 110.4‐m2 g−1 electrochemical active surface area (ECSA). Consequently, it is clear that Ni@(Pd/MWCNT) nanocatalyst is a promising nanocatalyst for direct formic acid fuel cells (DFAFCs).

The Role of Chemistry of the Oil-Field Water in the Distribution of Reservoir Pressures: A Case Study of Mishrif Reservoir in the Southern Oil-Fields, Iraq

Mishrif Formation is the main reservoir in oil-fields (North Rumaila, South Rumaila, Majnoon, Zubair and West Qurna) which located at Basrah southern Iraq. The Inductively coupled plasma-Mass spectrometer (ICP-MS) was used for the water chemistry analysis and Scanning Electron Microprobe (SEM) for the purpose of mineralogy diagnosis. A weak acidic water of salinity six-time greater than seawater plays a role in generating the formation pressure and controlling the fluid flow. The potentiometric subsurface maps were modeled and the direction of super-pressure sites that are of a great importance in the oil exploration were marked to pay attention during future drilling.

Technical research on vacuum distillation to purify magnesium to 99.99% purity

In this study, the distribution and evaporation principles of impurities in distilled magnesium metal were investigated using a low vacuum (8 × 104 Pa) distillation purification experiment and theoretical analysis. Provided all other factors remain unchanged (distillation time, pressure, and total area of evaporation), the optimum temperature for preparing high-purity Mg (99.99%) is 750 °C. A detailed analysis of purified Mg was obtained by inductively coupled plasma mass spectrometer (ICP-MS) for 10 major impurity elements. After distillation at 750 °C, low vapor pressure impurities in condensed magnesium, including Si, Mn, Al, Fe, Cu, Ni, and Sn were significantly reduced as other impurities were slightly reduced. Our analysis confirmed a decrease in the following impurities: Fe, Si, Mn, Cu, and Al were reduced from 21.8, 78.6, 68.4, 4.4, and 39.4 ppm to 1.2, 9.3, 6.0, 1.0, and 5.4 ppm, respectively; satisfying the 99.99% Mg standard. The evaporation rate and separation coefficient were calculated under experimental conditions. To better describe the distillation process of metallic magnesium under low vacuum conditions, the mean free path is also calculated in this study under actual conditions.

Chemical and microstructural characterization of ash from the Ubinas and Sabancaya volcanoes in Peru

In this study, volcanic ash from Ubinas and Sabancaya volcanoes in Peru were characterized by particle size, scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM/EDX), ICP MASS spectrometer, X-ray diffraction and specific gravity. The combined application of those techniques for the analysis provided complementary information, i.e., their elemental compositions and morphology. The results showed that the volcanic ashes (VA) have a particle size lower than 600 μm with a dominant size over 100 μm. Their mineralogical characteristics involve silica polymorphs, vitreous nature of silica and silicate particles, showing chemical heterogeneity within the micrometer sized particles and diverse morphology. The chemical composition of the ash is mainly SiO2, Al2O3, Na2O and CaO, with a high content of silica ranging from 57.78 to 66.14% and alumina ranges from 13.81 to 17.56%. The concentration of potential pollutant elements determined in products from Ubinas and Sabancaya volcanoes, namely As, Ba, Co, Cr, Cs, Fe, K, Mn, Mo, Sb, Sc, Sr, Th, Ti, U, V, and Zn, are reported. The different mineralogical characteristics among the studied volcanic samples would be related to their association with different volcanic eruptions. The chemical compositions and microstructure indicate that ashes have an origin and formation of andesitic and dacitic type.

A practical approach of high precision U and Th concentration measurement in acrylic

The Jiangmen Underground Neutrino Observatory (JUNO) will build the world’s largest liquid scintillator detector to study neutrinos from various sources. The 20 kilo tonne (kton) liquid scintillator will be stored in a 0.6 kton acrylic sphere with 35.4 m diameter due to the good light transparency, chemical compatibility and low radioactivity of acrylic. The concentration of U/Th in acrylic is required to be less than 1 ppt (10−12 g/g) to achieve a low radioactive background in the fiducial volume of the JUNO detector. The mass production of acrylic has started, and the quality control requires a fast and reliable radioassay on U/Th in acrylic. We have developed a practical method of measuring U/Th in acrylic to sub-ppt level using the Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The U/Th in acrylic can be concentrated by vaporizing acrylic in a class 100 environment, and the residue will be collected and sent to ICP-MS for measuring U/Th. All the other chemical operation is done in a class 100 clean room, and the ICP-MS measurement is done in a class 1000 clean room. The recovery efficiency is studied by adding the natural nonexistent nuclei 229Th and 233U as the tracers. The resulting method detection limit with 99% confidence can reach 0.04/0.09 ppt 238U/232Th in acrylic with (77.5 ± 3.4)% and (73.6 ± 4.1)% recovery efficiency. This equipment and method can not only be used for the quality control of JUNO acrylic, but also be further optimized for the radioassay on other materials with extremely low radioactivity, such as ultra-pure water and liquid scintillator.

Simultaneously deposited Pt-alloy nanoparticles over graphene nanoplatelets via supercritical carbon dioxide deposition for PEM fuel cells

One of the main barriers to the commercialization of polymer electrolyte membrane fuel cell (PEMFC) systems is the cost, which is largely due to the need of platinum (Pt)-containing catalysts. In order to overcome this issue, several methods have been developed. One of them is the supported electrocatalysts prepared by combining a low cost second metal with Pt. Motivated by this idea, in this study, nano-sized Pt-M (M = Ni, Fe, Cu) binary electrocatalysts were synthesized on the graphene nanoplatelets (GNPs) via supercritical fluid deposition (SFD) technique in order to decrease the cost and increase the activity of the catalysts. Because, the unusual properties of supercritical fluids (SFs), including tunable solvent strength, high diffusivity, low viscosity, and low surface tension, offer significant advantages over conventional techniques for materials processing. In this regard, compared to the other SFs, carbon dioxide (CO2) has received much more attention due to its easy accessibility to the supercritical state, relative benignity to the environment, chemical inertness, low toxicity, low cost. The supercritical carbon dioxide (scCO2) deposition technique involves firstly the dissolution of the metal precursor onto the support material, and then conversion of the metal precursor to its metallic form by means of thermal or chemical conversion. Synthesis of supported bimetallic nanoparticles (NPs) via scCO2 can be sequentially or simultaneously. Herein, we investigated the development of Pt-M (PtCu, PtNi, PtFe) alloy NPs on GNPs by scCO2 deposition via simultaneous addition of metal precursors. Subsequently, these catalysts were characterized by employing various characterization techniques and systems such as X-Ray Diffaction (XRD), Thermogravimetric Analysis (TGA), Inductively Coupled Plasma Mass Spectrometer (ICP-MS), Transmission Electron Microscopy (TEM), Raman Spectroscopy, Cyclic Voltammetry (CV), Rotating Disk Electrode (RDE) and PEM Fuel Cell performance tests. The obtained results revealed the formation of bimetallic catalysts within the size ranges from 1.6 to 2.1 nm. Furthermore, CV results demonstrate that PtNi/GNPs catalyst exhibit significantly high catalytic activity toward the PEM fuel cell reaction in comparison with the PtFe/GNPs and PtCu/GNPs. Also, PtNi/GNPs catalyst show about 2–4 times higher durability than the PtFe/GNPs and PtCu/GNPs catalysts in the accelerated degradation tests (ADTs). All results suggested that the PtNi/GNPs catalyst has great potential for PEM fuel cell applications.

Geochemical Classification and Geotectonic Setting of Granitic Gneisses from Southeastern Margin of Western Nigeria Basement

Chemical whole-rock major oxides and some trace element analyses were done on granitic gneiss rocks located on the southeastern margin of western Nigeria Basement Complex, exposed in parts of Dagbala-Atte District, southwestern Nigeria. This was meant to classify the rocks and to understand the tectonic setting in order to evaluate their crustal evolution. The chemical analyses were done using inductively-coupled plasma mass spectrometer. From the results obtained, these rocks classified into calc-alkaline to shoshonite series with metaluminous to peraluminous varieties, they are I-type granitoids of feroan composition. The granitic gneisses formed from metamorphism of granite and granodiorite. Tectonically, most of the rock samples plotted in the field of island arc, continental arc and continental-collisional granitoids, which indicated that the protolith granite and granodiorite are orogenic and are arc related inferring arc tectonic setting.

Efficient recovery of phosphorus and sulfur from Anaerobic Membrane Bioreactor (AnMBR) permeate using chemical addition of iron and evaluation of its nutrient availability for plant uptake

Anaerobic membrane bioreactors (AnMBRs) represent an emerging environmental biotechnology platform with the potential to simultaneously recover water, energy, and nutrients from concentrated wastewaters. The removal and beneficial capture of nutrients from AnMBR permeate has yet to be fully explored, therefore this study sought to foster iron phosphate recovery through a tertiary coagulation process, as well as characterize the recovered nutrient product (RNP) and assess its net phosphorus release, diffusion, and availability for plant uptake. One of the primary goals of this study was to optimize the dose of the coagulant, ferric chloride, and coagulant aid, aluminum chlorohydrate (ACH), for continuous application to the coagulation-flocculation-sedimentation (CFS) unit of an AnMBR pilot plant treating municipal wastewater, through controlled bench-scale jar tests. Anaerobic systems present unique challenges for nutrient capture, including high, dissolved hydrogen sulfide concentrations, along with settleability issues. The addition of the coagulant aid increases settleability, while enhancing phosphorus removal by up to 20%, decreasing iron demand. Water quality analysis indicated that a variety of factors affect nutrient capture, including the COD (chemical oxygen demand) concentration of the permeate and the limiting coagulant dose. COD >200 mg/L was shown to decrease the phosphorus removal efficiency by up to 15%. A combination of inductively coupled plasma optical emission spectrometer (ICP-OES) elemental analysis, inductively coupled plasma mass spectrometer (ICP-MS) elemental analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray absorption near-edge structure (XANES) spectroscopy analysis was used to characterize the P-rich RNP which revealed a 2.58% w/w phosphorus content and the lack of a well-defined crystalline structure. Detailed studies on resin extractable phosphorus to assess the plant uptake potential also demonstrated that iron-based P-rich RNPs may not be an effective fertilizer product, as they can act as a phosphorus sink in some agricultural systems instead of a source.

High Performance Liquid Chromatography-Determination of Different Speciations of Arsenic in Cosmetics by Inductively Coupled Plasma Mass Spectrometry

There is a way to determine four arsenic speciations simultaneously in cosmetic by using liquid chromatography (HPLC) with inductively coupled plasma mass spectrometer (ICP-MS). After being extracted by phosphoric acid solution, the samples were separated by PRP-X100 anion chromatographic column. The mobile phase was aqueous solution (pH=6.0) containing 1% methanol (V/V), 2.0 mmol/L NaH2PO4 and 0.2 mmol/L ethylene diamine tetraacetic acid (EDTA). The octopole reaction cell was adopted to eliminate mass spectrum interferences. The separation of AsIII､DMA､MMA and AsV was achieved within 12 min with flow rate of 1.00 mL/min and sample size of 100 μL. The recovery rates of AsIII, DMA, MMA and As Vranged from 80.6% to 107.2% and the relative standard deviations were less than 6.24% when the spiked amount was 0.10∼ 1.00 μg in different kinds of cosmetic samples. The developed method has the advantage of simplicity, sensitivity and good reproducibility, and can be used for the determination of arsenic speciations simultaneously in cosmetics.

Critical Minerals from Post-Processing Tailing. A Case Study from Bangka Island, Indonesia

The growing demand for critical raw materials (rare earth elements—REE, Nb, Ta, and others) enforces a need to look for their alternative sources. Distortions of the mineral supply chain caused by COVID-19 have necessitated a re-evaluation of what exists as mining waste from previous exploitation. Consequently, this study aims to provide an inventory of raw materials on the Indonesian Tin Islands (Bangka and Belitung). Geological and mineralogical examinations on Bangka have permitted an economic appraisal of tailings from the processing of cassiterite-bearing sands and confirmed the presence of REE-bearing minerals, chiefly monazite and xenotime, zircon, ilmenite, rutile, niobium-tantalum phases. In general, the mineral content of the tailings varies depending on the sampling site and the type of processing used during ore-production. ICP-MS (inductively coupled plasma–mass spectrometers) analyses revealed anomalous concentrations of LREE (light rare earth elements): La &gt; 5%, Ce &gt; 5%, Pr &gt; 1%, Nd &gt; 1%, Sm &gt; 1% and HREE+Y (heavy rare earth elements and yttrium) up to 2.51 wt%. High values have been found for the “most critical” metals of the HREE group: Dy (up to 0.34 wt%), Tb (up to 0.08 wt%), Eu (up to 61.8 ppm), Nd (&gt;1.0 wt%), and Y (up to 1.20 wt%). In addition, the following contents have been defined: Ga (to 0.03 wt%); Hf (to 0.64 wt%); Ta (to 0.08 wt%); Nb (to 0.23 wt%); W (to 0.14 wt%); Zr (&gt;5.0 wt%); and Sc (to 0.01 wt%). Such high concentrations suggest the tailing dumps to be a potential new source of “critical raw materials”.

Determination of Characteristic vs Anomalous 135Cs/137Cs Isotopic Ratios in Radioactively Contaminated Environmental Samples.

A contamination with the ubiquitous radioactive fission product 137Cs cannot be assigned per se to its source. We used environmental samples with varying contamination levels from various parts of the world to establish their characteristic 135Cs/137Cs isotope ratios and thereby allow their distinction. The samples included biological materials from Chernobyl and Fukushima, historic ashed human lung tissue from the 1960s from Austria, and trinitite from the Trinity Test Site, USA. After chemical separation and gas reaction shifts inside a triple quadrupole ICP mass spectrometer, characteristic 135Cs/137Cs isotope signatures (all as per March 11, 2011) were obtained for Fukushima- (∼0.35) and Chernobyl-derived (∼0.50) contaminations, in agreement with the literature for these contamination sources. Both signatures clearly distinguish from the characteristic high ratio (1.9 ± 0.2) for nuclear-weapon-produced radiocesium found in human lung tissue. Trinitite samples exhibited an unexpected, anomalous pattern by displaying a low (<0.4) and nonuniform 135Cs/137Cs ratio. This exemplifies a 137Cs-rich fractionation of the plume in a nuclear explosion, where 137Cs is a predominant species in the fireball. The onset of 135Cs was delayed because of the longer half-life of its parent nuclide 135Xe, causing a spatial separation of gaseous 135Xe from condensed 137Cs, which is the reason for the atypical 135Cs/137Cs fractionation in the fallout at the test site.

Elevated cadmium and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in residents living near electroplating industries.

This study aims to evaluate the body burdens of cadmium (Cd) associated with potential health impairment in residents living near electroplating industries. A total of 269 residents from exposure area and 106 from control area were recruited. We measured the blood and urinary Cd levels using an inductively coupled plasma mass spectrometer (ICP-MS); performed physical examinations; determined the urinary levels of β2-microglobulin (β2-MG), Nacetyl-β-D-glucosaminidase (NAG), and 8-hydroxy-2'-deoxyguanosine (8-OHdG); and evaluated the associations between Cd and these biomarkers. Blood and urinary Cd levels in exposure group were statistically higher than in control group (1.712 vs. 1.159 μg/L; 1.980 vs. 1.740 μg/L, respectively, p < 0.05). Urinary β2-MG and 8-OHdG levels in exposure group were also statistically higher (0.448 vs. 0.090 mg/L; 12.759 vs. 12.115 μg/L, respectively, p < 0.05), but urinary NAG levels showed no significant difference between the two groups (13.614 vs. 8.246 IU/L, p > 0.05). The proportion of abnormal nasal symptoms occurring in exposed subjects (88.8%) was much higher than in control subjects (78.2%, p < 0.05). Urinary Cd levels were positively correlated with blood Cd levels, urinary 8-OHdG, and NAG levels (r = 0.307, r = 0.185, r = 0.150, p < 0.05), but not correlated with urinary β2-MG levels (p > 0.05). In conclusion, our study revealed that residents living in close proximity to electroplating industries had elevated body burdens of Cd levels, as well as slight renal dysfunction and DNA oxidation damage.