ICP-AES Research Articles

Energy Dispersive X-Ray Fluorescence Spectrometry Using a Matrix Corrected Fundamental Parameters Algorithm vs. Acid Digestion with ICP-AES: A Comparison of Two Methods for Soil Elemental Analysis

ABSTRACT Energy dispersive X-ray fluorescence spectrometry (ED-XRF) is evaluated as an alternative to conventional acid-mediated soil digestion methods for analysis of aluminum (Al), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), silicon (Si), strontium (Sr), titanium (Ti), and zirconium (Zr). The Kellogg Soil Survey Laboratory (KSSL) currently uses microwave-assisted digestion with inductively coupled plasma – atomic emission spectrometry (ICP-AES) to measure the 12 elements (Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Sr, Ti, Zr). The equipment needed to conduct the digestion method is expensive, the materials are hazardous, and the method is laborious. The Kellogg Soil Survey Laboratory (KSSL) has observed variable elemental recoveries for certain elements. The objective of the study was to evaluate an ED-XRF method as an alternative to the KSSL digestion method. The literature offers few examples of X-ray fluorescence (XRF) method development and validation. The candidate ED-XRF method offered a more efficient, less expensive, and less hazardous approach for measuring the 12 elements. Relative to the digestion method, the candidate ED-XRF method showed improved precision and accuracy for specific elements.

Elemental composition and health risk assessment of PM10, PM2.5, at different microenvironments: Addis Ababa, Ethiopia.

This study was designed to evaluate the health risks faced by inhabitants living in the slum areas of Addis Ababa, Ethiopia. The levels of PM2.5 and PM10 and elemental composition of the PM10 were measured in indoors (in the kitchen and living room) and outdoors (at the roadside). A total of 75 sampling locations (45 indoor and 30 outdoor) were selected for the study. The levels of PM2.5 and PM10 were determined using an AROCET531S instrument, while an universal air pump was used for the sampling of PM10 for the determination of trace elements by inductively coupled plasma-optical emission spectroscopy (ICP‒OES). The health impacts of PMs on the inhabitants of twelve microenvironments (MEs), where they spend much of their daily time, were estimated. The total amounts of PM2.5 and PM10, and trace metals in PM10 found in the nine or twelve MEs ranged from 10.6-119, 128-185, and 0.007-0.197 μg m-3, respectively. According to the United States Environment Protection Agency (USEPA) guidelines, ten of the twelve MEs can cause significant health problems for inhabitants (HI > 1) due to PM2.5 and PM10. Thus, special attention should be given by stakeholders/inhabitants to minimize the health impacts on long-term exposure. This study assessed the risk of levels of trace elements on the inhabitants who spend most of their daily lives. The study revealed that the lifetime cancer risk values for the individual and cumulative trace elements were within the tolerable range set by the USEPA guidelines.

The active ingredient of Evodia rutaecarpa reduces inflammation in knee osteoarthritis rats through blocking calcium influx and NF-κB pathway.

Chronic inflammation significantly contributes to the progression of osteoarthritis (OA), and an anti-inflammatory small molecule derived from medicinal herbs could be a potential drug candidate for OA. Herein, we investigated the function and mechanism of Evodiamine (EAE), the active ingredient from Evodia rutaecarpa, in chondrocytes and macrophages in vitro and in vivo. The cytotoxicity of EAE was determined using an MTT assay. And the anti-inflammatory and anti-extracellular matrix (ECM) degradation effects of EAE were investigated using qRT-PCR, western blot (WB), immunofluorescence (IF). Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Fluo-4AM, IF and AutoDock were used to elucidate the molecular mechanisms and signalling pathways of the reducing-inflammatory properties of EAE on chondrocytes in vitro. Moreover, the effect of EAE on macrophage polarization was detected by IF and flow cytometry (FC). Ultimately, we explored the in vivo therapeutic efficacy of EAE in an anterior cruciate ligament transection (ACLT)-induced OA model. The finding demonstrated that EAE blocked the phosphorylation of IKBα and Ca2+ influx, thereby curbing inflammation and ECM degradation. Additionally, EAE can prevent the polarization towards the M1 phenotype. Thus, our findings suggest that EAE has great potential as a therapeutic drug for the treatment of OA.

Pollution Profile of the Panvel Creek, Raigad, Maharashtra, India: Analysis of the Heavy Metal Contamination

The concentration of heavy metal levels (Cd, Cu, Hg, Ni, Pb, and Zn) were assessed in water samples from Panvel creek, District Raigad, Maharashtra, West Coast of India. The heavy metals were analysed by using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Results of the study reveal that, Cu, Ni, Zn, and Hg were detected in water samples of Panvel creek whereas Pb and Cd were not reported. Levels of Cu range from not detectable to 0.037 ppm whereas concentration of Ni varies from not detectable to 0.048. Zn is the only metal which is consistently detected at both the sites during all seasons whereas its values were moderately high (0.108 ppm) during the monsoon at both sites. Highest values were recorded for Hg, especially during the pre-monsoon. Highest levels of Ni and Zn were detected at both sites during monsoon season whereas Cu, Pb, Hg and Cd were not detected during monsoon at all sites. Further, Cu and Zn were detected during post-monsoon, while other metals such as Ni, Pb, Hg and Cd remain not detectable. Zn was only heavy metal detected at both sites during all sampling seasons while Pb and Cd were absent from the water samples during all the seasons at all sites. Average concentration of heavy metals reported in Panvel creek was found to be in the order of Hg>Zn>Ni>Cu>Pb>Cd. Therefore, the coastal water from the Panvel creek is polluted by heavy metals. Absence of heavy metals like Pb and Cd is attributed to the waste discharged in the creek are free from these metals and is also beneficial to the coastal biota of the creek. Consistent occurrence of Cu, Ni, Zn, and Hg in Panvel creek should not be ignored considering their impact on the ecosystem and marine biota.

Evaluation of zinc, lead, and cadmium bioaccumulation in the liver of house sparrows (Passer domesticus) to assess environmental pollution in Meknes, Morocco

ABSTRACT Environmental pollution from heavy metals such as zinc (Zn), lead (Pb), and cadmium (Cd) poses serious risks to human health and ecosystems. This study examines the bioaccumulation of these metals in the livers of house sparrows (Passer domesticus) in Meknes, Morocco, using them as bioindicators of pollution. Fifty adult sparrows were collected from five areas: The Industrial Zone (IZ), Town Centre (TC), Sidi Said Bus Station (SS), Fes-Meknes Main Road (MR), and a Rural Site (Ref). Liver samples were analysed with Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). The highest Zn concentrations were found at IZ (111.43 µg/g) and Ref (90.66 µg/g), Pb at TC (4.17 µg/g), and Cd at IZ and TC (0.70 µg/g and 0.71 µg/g). Statistical analyses revealed significant correlations between metal levels. Clustering techniques identified three distinct contamination profiles. These results highlight house sparrows as reliable bioindicators for monitoring heavy metal pollution.

Assessment of Ecological Hazards in the Inaouen Wadi and Its Tributaries Using the Presence of Potentially Toxic Elements in Its Sediments

Inaouen wadi is the second largest tributary of the Sebou river, one of Morocco’s major rivers, which holds significant economic and social importance. Unfortunately, this watercourse is severely impacted by pollution from various human activities, particularly industrial sources. However, available data on the presence of potentially toxic elements (PTEs) that could harm human health in this region remain limited. PTEs pose major environmental risks due to their toxicity, persistence, and bioaccumulation. This study aimed to assess the concentrations of PTEs in the sediments of Inaouen wadi and its main tributaries based on sediment samples collected from 12 locations in 2019. The concentrations of Cd, Pb, Cr, Ag, Al, Cu, Fe, and Zn were measured using inductively coupled plasma atomic emission spectroscopy (ICP–AES), and sediment contamination levels were evaluated using multiple indices: the enrichment factor (EF), the geo-accumulation index (Igeo), the potential ecological hazard index (RI), and the modified ecological risk index (MRI). The results indicate that concentrations of Pb, Cd, Cr, Cu, Fe, and Zn are significantly influenced by urban discharges, particularly at sites S1, S3, and S5 near the cities of Taza and Oued-Amlil. The maximum values recorded were 7.01 g/kg for Pb, 0.9 g/kg for Cd, 0.1 g/kg for Cr, 19.9 g/kg for Fe and 1.9 g/kg for Zn. The enrichment factor (EF) revealed anthropogenic sources of Fe and Pb, confirming the human origin of these elements. The geo-accumulation index (Igeo) showed that the areas around stations S1, S3, and S5 are highly contaminated by Pb, Cd, and Fe, a finding also supported by the MRI. The study identified potential ecological risks at stations S1, S3, and S5, highlighting the urgent need for improved pollution management practices to mitigate environmental risks.

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.

Desulfurization of simulated and commercial liquid fuel on nano-ZnO fabricated walnut shells.

The current investigation involved the development of activated carbon, juglans regia activated carbon (JRACs), from walnut shells, scientifically known as Juglans regia. The ZnO nanorods were loaded on the activated carbon and referred to as ZnO@JRACs. Desulfurization efficiency was assessed through batch adsorption and compared to commercial activated carbon known as DARCO. The materials were characterized using PXRD (powder X-ray diffraction), FTIR (Fourier-transform infrared spectroscopy), ICP-AES (inductively coupled plasma atomic emission spectroscopy), BET (Brunauer-Emmett-Teller) surface area analysis, TEM (transmission electron microscopy) imaging, and TGA (thermal gravimetric analysis). The findings indicated that the materials have oxygen functionalities, a porous morphology, and a substantial specific surface area (BET) of 1269.92 m2/g for ZnO@JRACs. Zn atom concentration in the ZnO@JRACs surface was determined to be 1.16 atomic percent using ICP-AES. Desulfurization experiments were conducted on three liquid fuels, namely a single component model fuel, MSF (multicomponent simulated fuel), and commercial fuel (kerosene), under optimized conditions (8g/L adsorbent dosage in 10mL of fuel, 15min of contact time at room temperature). The conditions effectively removed ~ 98.9% of dibenzothiophene (DBT) from the single component model fuel. The observed order for adsorption capacity is as follows: ZnO@JRACs (63.6mgg-1) > JRACs (46.3mgg-1) > DARCO (26.1mgg-1). The analysis of multicomponent simulated fuel (MSF) using gas chromatography-flame photometric detector (GC-FPD) revealed significant removal percentages for different types of thiophenic sulfur. Specifically, the removal percentages were ~ 46.2%, 97.6%, and 99.4% for benzothiophene, dibenzothiophene, and 4, 6-dimethyldibenzothiophene, respectively. Kinetic studies have shown that the adsorption process is governed by a pseudo second-order reaction. Additional thermodynamic studies were conducted to further investigate the mechanism of adsorption. The spent synthesized composite ZnO@JRACs were thermally regenerated and can be reused for up to four cycles.

The Effect of Biochar Particle Size on the Leaching of Organic Molecules and Macro- and Microelements

Biochar is a carbon-rich material that has recently received attention due to its increasing agronomical potential. The agricultural utilization of biochar relates to its potential to act in the soil as a soil conditioner; nevertheless, complex information on the direct dependence of biochar’s physical properties (texture, particle size) and corresponding leaching and availability of organic molecules (e.g., the polycyclic and heterocyclic organic compounds) and inorganic mineral salts (based on micro- and macroelements) is still inconsistent. Multi-elemental analysis by using inductively coupled plasma atomic emission spectroscopy (ICP-OES) was used to assess the information on the contents and availability of macro- and microelements in studied commercial biochar samples. The results showed a statistically significant indirect relation between an increase in the size fraction of biochar and the content of aqueous-extractable K and Na and the direct relation with the aqueous-extractable Ca, Mg, and P. Compared to the macroelements, the detected contents of aqueous-extractable microelements were almost three orders lower, and the dependence on fraction size was not consistent or statistically significant. In addition, gas chromatography (GC) coupled with mass spectroscopy (MS) was further used to reveal the concentrations of available polycyclic aromatic and heterocyclic compounds in biochar samples. The detected concentrations of these types of organic compounds were far below the certified limits, and a statistically significant indirect correlation with particle size was also observed for all the studied biochar samples. The proposed methodological concept could provide the necessary insights into the description of biochar mineral content and its connection to biochar texture, the physicochemical properties, and the potential of biochar to release nutrients into the soil. These findings could help in the further assessment of biochar as a soil conditioner in modern agriculture.

New Brønsted–Lowry acid Co(II) complexes: Synthesis, characterization, and investigation of electrochemical application for sensing of salbutamol

In recent years, the employment of transition metal complexes for working electrode surface modification for sensor fabrication has become an area of research direction. Based on this, in this study, three Co(II) complexes: Co(phen)Cl2 (CoC12H8N2Cl2) (C1), and Brønsted–Lowry acids Co(phen)(HTA)Cl (CoC16H13N2O6Cl)(C2), and Co(phen)(HTA)2 (CoC20H18N2O12)(C3) were synthesized and characterized using various techniques such as UV–Vis, FT-IR, ICP OES, TGA, DTA, pXRD as well as electrolytic conductivity, and acid-base property analysis. C and C3 were found polycrystalline whose size falls within the nano range of 50 and 51 nm, respectively. The synthesis was intended to get materials for voltammetrically modifying glassy carbon electrodes for the determination of salbutamol. Salbutamolis a short-acting β2adrenergic receptor agonist that is applied for opening the medium and large airways in the lungs and eventually treats asthma among other problems. The electrochemical application of the synthesized materials was studied by fabricating through electropolymerization of C1, C2, and C3 on glassy carbon electrodes. The poly(C1)/GCE, poly(C2)/GCE, and poly(C3)/GCE) revealed effective surface area is 0.174 cm2, 0.183 cm2, and 0.281 cm2, respectively, and electrochemical catalysis of the materials increased with the number of the tartrate. The Rct values are 5686, 242, 216, and 185 Ω cm2, while the Cdl values are 9.93 × 10−8, 5.35 × 10−6, 1.25 × 10−5, and 2.72 × 10−5, for bare GCE, poly(C1)/GCE, poly(C2)/GCE and poly(C3)/GCE, respectively. Similarly, the rate of charge transfer (k°) increased significantly on the modified electrode compared to the bare GCE. Salbutamol demonstrated a single well-shaped irreversible oxidative peak at the modified electrodes in the ascending order of poly(C1)/GCE, poly(C2)/GCE, and poly(C3)/GCE when compared to a bare GCE.

Development of cellulose-supported Pd-nanocatalyst for the heck coupling and michael addition reactions

The development of reusable, bio-resource based nanocatalysts with high turnover numbers (TONs) is essential for increased sustainability in the chemical sector. Herein, cellulose-supported bio-resourced poly(hydroxamic acid) is employed as a ligand in the synthesis of a palladium nanocomposite (PdNc-PHA) that exhibits higher TONs that previously reported similar systems for the Mizoroki-Heck and Michael addition reactions. The PdNc-PHA catalyst was characterised using Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectrometry (EDX), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analyses. Results showed that the PdNc-PHA catalyst exhibits excellent durability and high catalytic activity in the Mizoroki-Heck and Michael addition reactions, leading to high yields of the desired corresponding products. The Mizoroki-Heck reaction of aryl/heteroaryl chlorides with olefins resulted in the production of cross-coupled products, while the Michael addition reaction of phenol/thiophenol and aliphatic cyclic/alicyclic amines with a variety of olefins synthesised the corresponding O-, S-, and N-alkylated products. The recycle and reusability of the catalyst were tested using 4-nitrochlorobenzene and butyl acrylate. The results demonstrated that the catalyst maintained its catalytic activity effectively for up to ten cycles without any noticeable loss in performance. This research represents a promising strategy for efficient catalysis based on bio-waste as a wealth material.

The characteristics of V, Sc, Cr and Ni within the Cambrian terrigenous-carbonate deposits found in the Syuldyukar kimberlite field (Western Yakutia)

The investigation of the Syuldyukar kimberlite field, located within the Yakut diamond-bearing province, involved approximately 4,000 X-ray fluorescence (XFA) analyses and 150 inductively coupled plasma atomic emission spectroscopy (ICP AES) analyses on the host sedimentary rocks of the Upper Cambrian Holomolokha formation in proximity to the kimberlite bodies. The results indicated a disruption in the correlation ratios when compared to background concentrations, while subclark levels of vanadium (V), scandium (Sc), chromium (Cr), nickel (Ni), and other elements remained consistent. The elements were divided into three categories: typomorphic elements for kimberlites (Cr, Ni, Co), elements associated with carbonatites (barium (Ba), strontium (Sr), neodymium (Nd), zirconium (Zr)), and elements characteristic of basalts (V, Sc, zinc (Zn)). High positive correlation coefficients were established for the specified elements in the background concentrations. However, ICP analyses indicated significant decreases in the correlation between elements from different groups in the near-kimberlite space at the Syuldyukar site. X-ray diffraction (XRD) studies showed that in the compression areas, the correlation ratios of various elements were inconsistent when compared to the stretching areas. The analysis of the XRF and ICP data reveled that the average elemental concentrations in the background and near-tube space were nearly identical, except for some unusual hurricane values, with variations showing only slight changes. The positive correlation of several elements likely reflects background geological processes, including sedimentation in a marine basin and subsequent transformations such as hypergenesis, diagenesis, and catagenesis. The significant decrease in correlation coefficients, even with background concentrations remaining stable, is likely due to the redistribution of elements in the fluid resulting from phreatomagmatic explosions linked to the intrusion of kimberlites. Aqueous chloride fluids were observed to most actively redistribute elements in areas experiencing local tectonic compression. The identified changes in the correlation ratios of background elemental concentrations in sedimentary rocks containing kimberlite could act as a new indicator for locating hidden diamond-bearing kimberlites.

Toxic and essential elements in honeybee venom from Slovakia: Potential health risk to humans

Honeybee venom is one of the natural substances produced by bees (Apis mellifera). Their venom gland produces venom which plays a defensive role. In this study a concentration of macro and trace elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Sb, Se, Sr, Pb and Zn) in foragers′ and honeybees′ venom was analysed by axial inductively coupled plasma optical emission spectrometry (ICP OES) with good validation parameters to differentiate the element accumulation ability in honeybee venom. Cumulative ability for some elements (As, Al, Ba, Cr, Li, Mo, Pb, and Zn) in bee venom was clearly demonstrated. Oppositely, levels of macro elements (Ca, K, Mg and Na) in venom were several times lower compared to the levels detected in foragers. Moreover, PCA analysis of bee samples showed that Cr was associated with locality Košice, and Cd with locality Krompachy; both have rich industrial history. Since some of analysed elements are potentially toxic for humans, a risk assessment for bee-stung scenario was also calculated. A new way of exposure to potentially toxic elements via honeybee stung was showed in this study. Non-carcinogenic risk assessment for humans to selected toxic elements (As, Cd, Cr, Ni, and Pb) demonstrated acceptable risk and moreover the same we may conclude for potential carcinogenic risk for beekeepers exposed to As, Cd, Ni, and Pb via venom over their whole life.

Ni/ZSM‐23 Catalysts: Effect of Impregnating Solvent on the Hydroisomerization of n‐Hexadecane

AbstractBifunctional catalysts are widely used in the hydroisomerization of long‐chain n‐alkanes, which are of great significance in the production of high value‐added chemicals. Herein, the Ni/ZSM‐23‐W and Ni/ZSM‐23‐EG catalysts were prepared using water and ethylene glycol, respectively. The catalysts were characterized using XRD, SEM, TEM, NH3‐TPD, Py–IR, H2‐TPR, H2‐TPD, ICP–OES, and XPS, and their catalytic performance was evaluated by conducting the hydroisomerization of n‐hexadecane as a model reaction. It was revealed that the polarity of the impregnating solvent has a significant impact on the dispersion of Ni nanoparticles. When employing ethylene glycol as a solvent, a strong interaction occurred between NiOx and ZSM‐23 in the Ni/ZSM‐23‐EG catalyst, which facilitated the formation of small‐sized and well‐dispersed Ni nanoparticles. Consequently, the Ni/ZSM‐23‐EG catalyst demonstrated a strong hydrogenation capacity, yielding an impressive 72.9% of iso‐hexadecanes yield.

Determination of adsorption capacity, regeneration ability, and aggregation tendency toward inorganic and organic pollutants of metal-doped carbon–silica composites in multicomponent systems

Abstract The main aim of the study was to develop a method for determining the adsorption capacity, regeneration ability, and aggregation tendency of metal-doped carbon–silica composites (iron-doped, C/Fe/SiO2, and manganese-doped, C/Mn/SiO2) against heavy metals and selected organic substances. The properties of these composites were compared with those of metal-free silica–carbon composite (C/SiO2). Inductively coupled plasma–optical emission spectrometry (ICP–OES) and high-pressure liquid chromatography were used to determine the adsorbed amounts and the desorption degree of organic/inorganic pollutants. Potentiometric titrations and electrophoretic mobility measurements were conducted to understand the mechanisms that were driving adsorption and particle aggregation. The size of the aggregates formed in the systems as well as the stability of the examined suspension were estimated by using ultraviolet-visible spectrophotometry. The performed experiments showed that the selected combination of methods is appropriate to determine the potential of metal-doped carbon–silica composites as adsorbents as well as the ease of their removal with adsorbed contaminants from aqueous solutions by sedimentation.

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.

Revolutionizing sensing technologies: Crafting a green, ultra-sensitive bismuth optical sensor via fixation of 5-(2′,4′-dimethyl-phenylazo)-6-hydroxypyrimidine-2,4-dione on PVC membrane

An innovative and exceptionally responsive optical sensing device engineered to selectively identify Bi(III) ions in water-based solutions. The sensing component, 5-(2′,4′-dimethylphenylazo)-6-hydroxypyrimidine-2,4-dione (DMPAHPD), is incorporated into a plasticized polyvinyl chloride (PVC) membrane. The sensor demonstrates an exceptional selectivity for Bi(III) within a broad dynamic range spanning from 7.5 × 10−10 to 4.2 × 10−5 M at pH 2.25. Notably, it achieves lower quantification and detection limits of 7.25 × 10−10 and 2.15 × 10−10 M, respectively. The optode membrane’s response to Bi(III) proves to be entirely reversible, demonstrating remarkable selectivity for Bi(III) ions over a diverse range of other cations and anions. The sensor exhibits favorable performance characteristics, including good reversibility, a wide dynamic range, a prolonged lifespan, sustained response stability over the long term, and high reproducibility. This visual chemical sensor exhibits potential for real-world usage, offering consistent outcomes when assessing Bi(III) levels in matrices such as water, soil, plants, biological and synthetic mixtures. Importantly, the sensor’s performance is comparable to corresponding data achieved from inductively coupled plasma atomic emission spectroscopy (ICP-AES).

Tuning the toughness, strength, and biological properties of functionally graded alumina/titania-based composites for use in bone repair applications

In this study, functionally graded composite (FGC) was prepared using a high-energy ball mill by fabricating five layers of alumina (Al2O3), titania (TiO2), hydroxyapatite (HA), and iron oxide (Fe3O4), which were sintered at 1100 °C to create an FGC sample. Scanning electron microscopy (SEM), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and weight loss measurements were used to assess bioactivity and biodegradation after immersing samples in simulated body fluid (SBF). Also, the antimicrobial activity and biocompatibility of these layers were evaluated. Furthermore, their electrical, dielectric, and mechanical properties were examined. The results revealed that all sintered layers were bioactive, and adding HA and Fe3O4 enhanced this desired property. Also, S. aureus bacterial growth was inhibited by TiO2 and Fe3O4. Fortunately, the sintered layers showed no cytotoxic effect, validating the ICP findings that demonstrated acceptable biodegradation. Adding HA and Fe3O4 enhanced fracture toughness in another hopeful outcome, which is crucial for biomaterial efficacy and long-term therapeutic success. Moreover, the compressive strength of all the layers and the FGC sample was 191.7, 182.2, 171.18, 159.8, 142.5, and 171.1 MPa. Layers 3, 4, and 5 notably had a compressive strength similar to cortical bone. This means that implanting these layers into human bone will protect the bone around them from stress-shielding action. Finally, the successive increase in HA/Fe3O4 contents increased the electrical conductivity. Accordingly, the prepared FGC sample and its layers are attractive bone substitute materials.

Efficient Cu‐Based Mixed Oxides Catalyst for α‐Alkylation of Ketones with Alcohols

AbstractA series of Cu‐based mixed oxides were prepared by calcinations of corresponding CuMgAl‐layered double hydroxides precursors at different temperatures with nominal Cu/Mg/Al ratios of 1 : 1 : 2(Cu‐LDH‐1), 1 : 2 : 1(Cu‐LDH‐2),1 : 1 : 1(Cu‐LDH‐3), and 2 : 1 : 1(Cu‐LDH‐4). The synthesized catalysts were characterized using X‐ray diffraction, high‐resolution transmission electron microscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, inductively coupled plasma atomic emission spectroscopy (ICP‐AES), and N2 physisorption analysis techniques. All as‐obtained catalysts showed adequate catalytic performance for the α‐alkylation of ketones with alcohols through a hydrogen autotransfer mechanism. The catalyst CuMgAl‐I‐650 (obtained by calcining Cu‐LDH‐1 at 650 °C) displayed the highest activity and selectivity. Using this catalyst system, a wide range of branched ketones were synthesized in good to excellent isolated yields. Moreover, the catalyst CuMgAl‐I‐650 could be recycled and reutilized for four cycles without any significant loss of activity and selectivity. This study provides a very simple and inexpensive catalysis based on transition metals, which are in abundance on earth.

Developing a novel calcium silver zeolite for caries management

ObjectiveTo develop a novel calcium silver zeolite (Ca-Ag-Zeo) and assess its biocompatibility, physiochemical properties and antimicrobial effects.MethodsCa-Ag-Zeo was synthesized using ion-exchange method with calcium chloride, silver nitrate and Zeolite X (Zeo). Silver zeolite X (Ag-Zeo) and Zeo were set as control. The chemical structure, morphology, crystal structure and elemental composition of Ca-Ag-Zeo was characterized by X-ray diffraction spectrum, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy, respectively. Its biocompatibility on the human gingival fibroblasts was assessed by cell counting kit-8 assay. Its physiochemical properties were determined by the released calcium and silver ion using Inductive Coupled Plasma Emission Spectrometry for up to 12 weeks. The antimicrobial properties on Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, and Candida albicans were assessed by minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) assay.ResultsCa-Ag-Zeo with a hexagonal cage structure was synthesized. As for biocompatibility, the half-maximal inhibitory concentration (± SD in mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo in human gingival fibroblasts were 0.52 ± 0.05, 0.15 ± 0.01 and 3.35 ± 0.58, respectively (Zeo > Ca-Ag-Zeo > Ag-Zeo; p < 0.05). As for physiochemical properties, the accumulated ion release (± SD in mg) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 0.011 ± 0.003, 0 and 0 for calcium ion, respectively (Ca-Ag-Zeo > Ag-Zeo, Zeo; p < 0.001), and 0.213 ± 0.032, 0.209 ± 0.019 and 0 for silver ion, respectively (Ca-Ag-Zeo, Ag-Zeo > Zeo; p < 0.001). As for anti-microbial ability, the MBC/MFC (mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 32, 16 and > 256 against Streptococcus mutans; 32, 16, > 256 against Lactobacillus acidophilus; 16, 16, and 256 against Lactobacillus casei; 0.25, 0.125; and 2, 1, > 256 against Candida albicans, respectively.ConclusionA novel Ca-Ag-Zeo was developed. It presented better biocompatibility compared to Ag-Zeo. It released calcium and silver ions sustainably, and it could inhibit the growth of common cariogenic microorganisms.