Search Results (357)

The anodic behavior of zinc electrodes is important for energy storage, corrosion protection, electrochemical processing, and other practical applications. This study investigates the anodic galvanostatic polarization of zinc foil and bulk electrodes in aqueous oxalic acid solutions, revealing significant differences in their electrochemical behavior, particularly in induction period durations. The induction period’s duration depended on electrolyte concentration, current density, and temperature. Notably, the temperature dependence of the kinetics exhibited contrasting trends: the induction period for foil electrodes increased with temperature, while that of bulk electrodes decreased. Chemical analysis and polishing treatment comparisons showed no significant differences between the foil and bulk electrodes. However, Scanning Electron Microscopy (SEM) observations of samples anodized at different temperatures, combined with Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES) analysis of dissolved electrode material, provided insights into the distinct anodic behaviors. X-ray Diffraction (XRD) studies further confirmed these findings, revealing a crystallographic orientation dependence of the anodic behavior. These results provide detailed information about the electrochemical properties of zinc electrodes, with implications for optimizing their performance in various applications. Full article

The uMlazi River receives effluents from wastewater work before feeding the Shongweni Dam. However, local communities are consuming fish from this dam for protein supplements. This study was undertaken to investigate the metal concentrations in the water and sediment, the general health of Coptodon rendalli and Oreochromis mossambicus, and metal bioaccumulation. Sampling was conducted during the dry (July–August) and wet seasons (November and December) in 2021. Water was sampled using acid-pre-treated sampling bottles, whereas sediment was collected using the Van Veen grab at the inflow, middle, and dam wall. Fish were collected, and their tissues were digested using aqua regia. Metal concentrations were measured using inductively coupled plasma optical emission spectroscopy (ICP-OES). This data manuscript reports the physical parameters of the water and concentrations of antimony, arsenic, cadmium, copper, iron, manganese, lead, selenium, and strontium in the water and sediment from the Shongweni Dam. Moreover, the fish morphometric data and metal concentrations observed in the muscle are also presented. This data could be used as baseline information on metal concentrations in the Shongweni Dam. Moreover, it provides insight into the potential impact of wastewater effluents on metal increases in freshwater bodies. Full article

Platinum has emerged as an optimal catalyst for the selective hydrogenation of nitroarenes owing to its high hydrogenation activity, selectivity, and stability. In this study, we report the fabrication of platinum nanoparticles stabilized on a composite support consisting of gum acacia polymer (GAP) and TiO₂. It was engineered for the targeted reduction of nitroarenes to arylamines via selective hydrogenation in methanol at ambient temperature. The non-toxic and biocompatible properties of GAP enable it to act as a reducing and stabilizing agent during synthesis. The synthesized nanocatalyst was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Morphological and structural analyses revealed that the fabricated catalyst consisted of minuscule Pt nanoparticles integrated within the GAP framework, accompanied by the corresponding TiO₂ nanoparticles. Inductively coupled plasma optical emission spectrometry (ICP-OES) was employed to ascertain the Pt content. The mild reaction conditions, decent yields, trouble-free workup, and facile separation of the catalyst make this method a clean and practical alternative to nitroreduction. Selective hydrogenation yielded an average arylamine production of 97.6% over five consecutive cycles, demonstrating the stability of the nanocatalyst without detectable leaching. Full article

A nanoparticle formulation was generated from distiller dried grains with solubles (DDGS), and its effect on the production of anthraquinones (AQs) was evaluated on Rubia tinctorum hairy roots. The DDGS material was washed with water and ethyl acetate to remove mainly the soluble organic/inorganic molecules and reduce the fat content, respectively, followed by an alkaline treatment to remove the polysaccharides. The resulting alkaline solutions were then lyophilized and redispersed in deionized water to generate a monodispersed nanoparticulate formulation (DDGS-NP) with a hydrodynamic diameter and zeta potential of 227 ± 42 nm and −53 ± 7 mV, respectively. The formulation demonstrated good colloidal stability over time, and sterilized DDGS-NPs maintained comparable physicochemical properties. The nanoparticles were enriched in protein fractions, unsaturated fatty acids, and orthophosphate anion components from DDGS, as determined by solid-state Nuclear Magnetic Resonance (NMR), X-ray photoelectron spectroscopy (XPS), organic elemental analysis (OEA), and inductively coupled plasma optical emission spectrometry (ICP-OES) techniques. The DDGS-NPs were tested at different concentrations on Rubia tinctorum hairy roots, in comparison to or in combination with methyl jasmonate (MeJ), for their capacity to induce the production of AQs. All DDGS-NP concentrations increased the production of specific AQs to 7.7 (100 mg L⁻¹), 7.8 (200 mg L⁻¹), and 9.3 µmol/gFW (500 mg L⁻¹), with an extracellular AQ accumulation of 18 µM for the highest DDGS-NP concentration, in comparison with the control hairy roots (~2 µM AQ). The plant growth was not affected at any of the tested nanoparticle concentrations. Interestingly, the combination of DDGS-NPs and MeJ resulted in the highest extracellular AQ accumulation in R. tinctorum root cultures. Full article

This study evaluated fecal near-infrared spectroscopy (fNIRS) potential to predict three external markers (Yb, Ti, and polyethylene glycol (PEG)) and dry matter digestibility (DMD) calculated from these markers and fiber fractions. A total of 192 fecal samples were collected from 576 Ross 308 male chicks supplemented with TiO₂ (2 g/kg), Yb₂O₃ (50 mg/kg), and PEG (5 g/kg) for 8 d. Reference values for Ti and Yb were obtained using an inductively coupled plasma–optical emission spectrometer, for fiber fractions via ANKOM, and for PEG content using an ad hoc fNIRS model. Prediction models were developed in external validation with 25% of the samples. Good and fair prediction models were built for Ti and Yb, respectively, and considered adequate for rough screening. The DMD models based on Yb and ADF were unreliable, whereas the model based on Ti was suitable for rough screening. The PEG prediction model built during the adaptation period performed exceptionally well; however, the DMD prediction based on PEG highlighted limitations due to diet differences during both the adaptation and experimental periods. In conclusion, fNIRS shows promise for screening Ti and Yb fecal content and DMD using Ti. However, tailored PEG prediction equations need to be developed for each specific diet. Full article

Water quality should be tested to ensure it is acceptable for the healthy growth of plants and animals, and water hardness is one of the important testing indexes. Herein, a novel approach was proposed to achieve high accuracy and rapid quantitative analyses of water hardness by combining one-point calibration laser-induced breakdown spectroscopy (OPC–LIBS) and aerosolization. First, the water samples are aerosolized via the aerosol generation device and the LIBS spectra of aerosols are obtained. Then, a modified OPC–LIBS model is used to determine the elemental contents of the aerosols via LIBS spectra, in which the plasma temperature is calculated using the Multi-Element Saha–Boltzmann (ME–SB) plot. One suitable standard liquid sample (the concentrations of Ca, Mg, and Sr were 50 mg/L, 50 mg/L, and 500 mg/L, respectively) was selected to evaluate the quantitative performance of the modified OPC–LIBS. Then, the Ca and Mg concentrations in the three real water samples (from the Yangtze River, reservoir, and underground) were detected and quantified by the proposed method, and the quantitative results of three LIBS calibration methods were compared with that of inductively coupled plasma optical emission spectroscopy (ICP–OES). The average relative error of Ca and Mg found in the OPC–LIBS results was lower by 22.23% than the internal standard method and 14.50% lower than the external standard method. The method combining modified OPC–LIBS and aerosolization can achieve high-precision rapid quantification of water hardness detection, which provides a new path for rapid detection of water hardness and is expected to make online detection a reality in the water quality testing field. Full article

Taxco de Alarcón (Mexico) has been affected by mining activities and the presence of potentially toxic elements (PTEs). In this study, water samples from the Acamixtla, Taxco, and San Juan rivers were analyzed using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) to determine PTE concentrations. Statistical analyses included principal component analysis, Pearson’s correlation, the Pollution Index, and a Health Risk Assessment. Additionally, solid samples from the San Juan River with leachate from the “La Guadalupana” Mine (RSJMG S2.3) were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Identified PTEs included As, Cr, Ni, Zn, Fe, Mn, Cu, Cd, Pb, Se, and Li. Principal component analysis explained 94.8% of the data variance, and Pearson’s correlation revealed significant associations (p < 0.05) among Fe, As, Cu, Cd, Pb, and Zn. The RSJMG S2.3 site exhibited the highest Pollution Index value (8491.56) and the highest health exposure risks. Lower contamination levels at other sites may be attributed to the complexation of PTEs with ferrihydrite, which was identified in the RSJMG S2.3 site through microscopy and infrared analyses. These findings suggest that the in situ formation of ferrihydrite may enhance the adsorption of PTEs, thereby mitigating environmental contamination and potential health risks. Full article

Microplastics (MPs) have emerged as pervasive environmental contaminants due to their widespread presence across various ecosystems, including their use in single-use plastic food ware and table salt dispensers. This issue coincides with the presence of heavy metals in water sources in Doha, Qatar. Fourier Transform Infrared (FTIR) analysis revealed that the plastic plate and spoon were composed of polyolefin, with the spoon exhibiting additional peaks that indicated oxidation or the presence of additives. Thermogravimetric Analysis (TGA) revealed that the spoon exhibited higher thermal stability, retaining approximately 10% of its mass at 700 °C, than the plate, which retained 2%, indicating the presence of complex additives or contamination. MPs in food-grade salt samples were verified through filtration and Fourier Transform Infrared (FTIR) Spectroscopy, identifying polymers such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). These MPs likely stem from exposure to packaging or environmental contaminants. FTIR spectra confirmed the integrity of the polymers after treatment. Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES) analysis revealed varying levels of heavy metals in bottled and tap water, with notable findings including detectable arsenic and lead in both, higher calcium and magnesium in bottled water, and the presence of copper present in tap water only, highlighting potential health and infrastructure-related concerns. These results highlight the possible risks associated with exposure to MPs and heavy metals from everyday products and water sources, underscoring the need for enhanced regulatory oversight and safer material choices to ensure protection. Full article

Trace elements, which may have harmful health effects, are present in the environment at varying concentrations. In Albania, data on exposure risks are limited. This study aimed to assess and compare the concentrations of various trace elements (aluminum, arsenic, boron, calcium, cadmium, chromium, copper, iron, potassium, magnesium, manganese, nickel, lead, and zinc) in the hair of cattle and sheep raised in Central Albania (Tirana and Elbasan Counties). Hair samples were collected from 25 cattle and 25 sheep per county and analyzed using inductively coupled plasma–optical emission spectroscopy. Zinc concentrations were significantly higher in cattle than in sheep (p = 0.029), while no differences were observed between counties (p > 0.05), indicating similar environmental conditions. Copper (17.84, 95%CI: 13.63–16.34 and 15.84, 95%CI: 14.00–17.69 mg/kg in cattle, and 15.58, 95%CI: 13.61–17.56 and 14.14, 95%CI: 12.07–16.20 mg/kg in sheep, in Elbasan and Tirana County, respectively), arsenic (2.08, 95%CI: 1.45–1.21 and 1.51, 95%CI: 1.19–1.81 mg/kg in cattle, 1.73, 95%CI: 1.38–2.07 and 1.39, 95%CI: 1.02–1.75 mg/kg in sheep, in Elbasan and Tirana County, respectively), and cadmium (2.36, 95%CI: 1.63–2.07 and 2.00, 95%CI: 1.68–2.32 mg/kg in cattle, 2.00, 95%CI: 1.59–2.40 and 1.71, 95%CI: 1.39–2.02 mg/kg in sheep, in Elbasan and Tirana County, respectively) concentrations exceeded the values reported in the literature, likely due to contamination from local mining and metal processing activities. Further research is needed to determine the sources of contamination and assess potential risks to animal and human health. Full article

Sediments are key players in the optimum functioning of ecosystems; however, they also represent the largest known repository of harmful contaminants. The vast variety of these sediment-associated contaminants may exert harmful effects on marine communities and can impair ecosystem functioning. Whole-cell biosensors are a rapid and biologically relevant tool for assessing environmental toxicity. Therefore, in this study, we developed a bioassay-based toxicity measurement system using genetically modified bacteria to create a whole-cell optical biosensor. Briefly, reporter bacteria were integrated and immobilized using a calcium alginate matrix on fiber-optic tips connected to a photon counter placed inside a light-proof, portable case. The calcium alginate matrix acts as a semi-permeable membrane that protects the reporter-encapsulated optical fiber tips and allows the inward passage of toxicant(s) to induce a dose-dependent response in the bioreporter. The samples were tested by directly submerging the fiber tip with immobilized bacteria into vials containing either water or suspended sediment samples, and the subsequent bioluminescent responses were acquired. In addition to bioavailable sediment toxicity assessments, conventional chemical methods, such as liquid chromatography–mass spectroscopy (LC-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES), were used for comprehensive evaluation. The results demonstrated the efficacy of the biosensor in detecting various toxicity levels corresponding to identified contaminants, highlighting its potential integration into environmental monitoring frameworks for enhanced sediment and water quality assessments. Despite its utility, this study notes the system’s operational challenges in field conditions, recommending future enhancements for improved portability and usability in remote locations. Full article

Spodumene (LiAlSi₂O₆) is a key lithium source mineral for energy storage devices, making the accurate and rapid analysis of its elemental composition crucial for the battery industry. This study explores the use of laser-induced breakdown spectroscopy (LIBS) combined with the standard addition method to analyze Be, Na, and K in spodumene. The method achieved relative errors of 5%–15% compared to inductively coupled plasma optical emission spectroscopy (ICP-OES), without requiring certified standards. To ensure accuracy, non-resonance emissions were used for Be and Na to minimize self-absorption effects. Although K analysis faced challenges due to strong self-absorption in resonance emissions, focusing on weak edge intensity reduced the relative error significantly. Our results suggest that LIBS combined with the standard addition method is a promising approach for lithium ore analysis, eliminating the need for certified standard materials and complex sample preparation steps such as acid digestion and high-factor dilution. Full article

Metal ion measurements using inductively coupled plasma optical emission spectroscopy revealed twofold-higher zinc content in rat brain compared to spinal cord. One hypothesis to explain this difference is the high prevalence of synapses that corelease glutamate and zinc in the brain, marked by the vesicular Zinc Transporter-3 (ZnT3). In contrast, spinal cord tissue showed significantly higher calcium content, reflecting calcifications in the arachnoid. The above observations were made in 60-day-old adult male and female rats fed ad libitum or a restricted diet. In this study, we asked if the calcium and zinc content of the brain and spinal cord was species-specific or evolutionarily conserved, and whether the distinct concentration of zinc in the brain and spinal cord resulted from a different expression pattern of ZnT3, the primary transporter in synaptic vesicles. To address these questions, we examined 8-week-old wild-type male and female mice raised under conventional laboratory conditions and used a knock-in mouse that expresses a human influenza hemagglutinin epitope tag at the C terminus of the endogenous ZnT3 gene to assess the transporter’s abundance in spinal cord sections. Our results show conserved inverse differences in zinc and calcium content in mouse brain and spinal cord, but detectable ZnT3 signal in spinal cord. Whereas vesicular zinc modulates glutamatergic and GABAergic signaling and sensory processing, the functional significance of calcium aggregates in the arachnoid remains unknown. Full article

Magnetic zeolite nanocomposites (NCs) have emerged as a promising class of hybrid materials that combine the high surface area, porosity, and ion exchange capacity of zeolites with the magnetic properties of nanoparticles (NPs), particularly iron oxide-based nanomaterials. This review provides a comprehensive overview of the synthesis, characterization, and diverse applications of magnetic zeolite NCs. We begin by introducing the fundamental properties of zeolites and magnetic nanoparticles (MNPs), highlighting their synergistic integration into multifunctional composites. The structural features of various zeolite frameworks and their influence on composite performance are discussed, along with different interaction modes between MNPs and zeolite matrices. The evolution of research on magnetic zeolite NCs is traced chronologically from its early stages in the 1990s to current advancements. Synthesis methods such as co-precipitation, sol–gel, hydrothermal, microwave-assisted, and sonochemical approaches are systematically compared, emphasizing their advantages and limitations. Key characterization techniques—including X-Ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning and Transmission Electron Microscopy (SEM, TEM), Thermogravimetric Analysis (TGA), Nitrogen Adsorption/Desorption (BET analysis), Vibrating Sample Magnetometry (VSM), Zeta potential analysis, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and X-Ray Photoelectron Spectroscopy (XPS)—are described, with attention to the specific insights they provide into the physicochemical, magnetic, and structural properties of the NCs. Finally, the review explores current and potential applications of these materials in environmental and biomedical fields, focusing on adsorption, catalysis, magnetic resonance imaging (MRI), drug delivery, ion exchange, and polymer modification. This article aims to provide a foundation for future research directions and inspire innovative applications of magnetic zeolite NCs. Full article

Cylindrospermopsin is an emerging cyanotoxin that can lead to phytotoxicity through different mechanisms. The presence of CYN in irrigation waters is of concern due to potential accumulation in plants, increasing the risk of human exposure by the consumption of vegetables. In this case, it is proposed to evaluate the effects of CYN on a crop considered staple food in Colombia, such as Solanum tuberosum, group Phureja var Criolla Colombia, known as “yellow potato”. This work evaluates for the first time the effects of CYN in potato plants exposed to this toxin using two different irrigation systems, surface and sprinkler irrigation. The parameters evaluated were CYN bioaccumulation and biotransformation in different parts of the potato plants irrigated with water containing CYN at environmentally relevant concentrations (84.65, 33.80, 3.05 and 3.05 µg/L after first, second, and third to fourth applications, respectively) and changes in nutritional mineral content in tubers. For this purpose, the concentrations of CYN and its potential metabolites in leaves, stem, roots, and tubbers of the plants exposed to the toxin were determined by Ultra-high Performance Liquid Chromatography–MS/MS (UHPLC-MS/MS). Mineral content was determined by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). CYN bioaccumulation was detected only in aerial parts of plants with sprinkler irrigation. A total of 57 CYN metabolites were found, and the main differences obtained in CYN biotransformation are linked to tissues and exposure conditions. There are significant differences in levels of Ca, K, Mg, Na, P, Cu, Fe, Mn, and Zn in tubers depending on CYN treatment, with higher contents after surface irrigation, and lower content with sprinkler application. These results demonstrate that the exposure conditions are an important factor for the potential presence and effects of CYN in potato plants. Full article

Gold nanoparticles (AuNPs) were synthesised using ultrasonic spray pyrolysis (USP) with the addition of polyvinylpyrrolidone (PVP) as a stabilising agent and subsequently dried via lyophilisation. The resulting dried AuNPs were redispersed in ethanol and homogenised to ensure uniform dispersion. This AuNP dispersion was then deposited onto a ceramic substrate—aluminum oxide (Al₂O₃)—using plasma jet printing. Comprehensive characterisation of the dispersion, AuNPs, and the resulting printed lines was performed using the following methods: inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), measurements of dispersion viscosity and printed line roughness. ICP-OES confirmed consistent gold content in the AuNP dispersion, while the SEM and EDS analyses revealed predominantly spherical AuNPs with minimal aggregation and similar size distributions. TEM, SAED, and STEM/EDS confirmed that the crystalline structure and elemental composition of the AuNPs had diverse morphologies and strong gold signals. The UV-Vis, DLS, and zeta potential measurements indicated moderate colloidal stability, and thermogravimetric analysis (TGA) verified the AuNPs dispersion’s composition. The AuNP dispersion exhibited thixotropic behaviour favourable for printing applications, while confocal microscopy confirmed smooth, uniform printed traces, with an average surface line roughness of 1.65 µm. The successful use of plasma printing with the AuNP dispersion highlights its potential for functional material applications in electronics. Full article