Search Results (318)

To investigate the biosilicification capabilities of Bacillus mucilaginosus and Bacillus polymyxa, silicon concentrations in supernatants from quartz and calcium silicate cultures were monitored over a 12-day period using inductively coupled plasma optical emission spectrometry (ICP-OES). Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to evaluate changes in the absorption intensity of Si–O–Si characteristic peaks, crystalline phase transformations in the reaction products, and the microstructural morphology of quartz and calcium silicate before and after microbial leaching. The results show that after leaching with B. mucilaginosus, the dissolved silicon concentration in the quartz supernatant reached a maximum of 73.868 mg/L on day 8. In contrast, following treatment with B. polymyxa, the silicon concentration in the calcium silicate supernatant peaked earlier, at 149.153 mg/L on day 4. After microbial leaching, both substrates exhibited marked changes in the intensity of the infrared absorption peaks at 1071 cm⁻¹ and 1083 cm⁻¹, suggesting the formation of Si–O–R type organosilicon complexes. Iron tailings (containing inert silica) and fly ash (containing active silica) were selected for experimental validation. Following treatment with B. mucilaginosus for desilication over an 8-day period, the activity index of iron tailings increased from 77.83% to 90.51%, while that of fly ash rose from 66.32% to 85.01%. ICP-OES analysis confirmed that under the action of B. mucilaginosus, the trends in silicon concentration and activity index in the supernatant of silica-containing solid wastes, such as iron tailings and fly ash, were consistent with those observed in quartz, thereby demonstrating effective biological desilication. These findings provide novel insights into the development of environmentally sound disposal methods for a wider range of solid waste types. Full article

Lithium carbonate is one of the most prescribed mood stabilizers worldwide and remains the first-line pharmacological treatment for bipolar disorder (BD). Its therapeutic efficacy is well established; however, lithium (Li) has a narrow therapeutic index, and prolonged or excessive intake can cause renal, neurological, or endocrine toxicity. In Brazil and globally, lithium-based formulations are widely commercialized; however, only Brazil adopts a specific regulatory classification distinguishing reference, generic, and similar medicines. Despite its extensive clinical use, studies monitoring the actual Li concentration in pharmaceutical products are extremely scarce. This study quantified Li concentrations in different formulations available in Brazil to evaluate their chemical uniformity, estimated daily intake, and potential health risks. Samples were digested and analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Statistical analysis with the Kruskal–Wallis test revealed significant differences among formulations (p = 0.012), confirming non-uniform Li content. Measured concentrations ranged from 245.47 to 315.24 mg/kg, with generic products showing the highest values. The calculated daily intake (DI) and chronic daily intake (CDI) increased with therapeutic dose (600–1800 mg/day), and higher-dose regimens frequently exceeded the permitted daily exposure (PDE) value for Li established by International Council for Harmonisation Guideline for Elemental Impurities (Revision 2) (ICH Q3D (R2) (0.55 mg/day). Moreover, hazard quotient (HQ) values above 1 in some scenarios indicated potential health risks associated with excessive or long-term Li exposure. As one of the first studies to quantify Li in marketed formulations, this work underscores the need for systematic monitoring and stricter quality control to ensure therapeutic safety. Full article

Fluoxetine and carbamazepine are widely prescribed psychotropic drugs, yet few studies have quantified metal(loid) impurities in these medicines, which may pose health risks to patients. This study aimed to determine concentrations of As, Cd, Cr, Cu, Fe, K, Mg, Mn, P, Pb, Se, and Zn in brand, similar, and generic samples of fluoxetine and carbamazepine marketed in Campo Grande, Brazil. Drug samples were purchased from local pharmacies, digested with acid, and analyzed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Results showed that arsenic was detected only in fluoxetine samples, with concentrations ranging from 0.068 to 0.217 mg/kg, all below national and international limits. Phosphorus presented the highest levels, especially in fluoxetine, reaching up to 14,000 mg/kg, and up to 93 mg/kg in carbamazepine. Other elements such as Fe (0.07–3.03 mg/kg), Mg (0.21–259 mg/kg), K (up to 45 mg/kg), Se (up to 1.5 mg/kg), and Zn (up to 4.2 mg/kg) were also quantified, while Cd, Cr, Cu, and Pb were below detection limits. The hazard index (HI) exceeded 1 for all carbamazepine samples and for one brand, two similar, and three generic fluoxetine samples, indicating that the intake of these medications may pose potential health concerns. These findings underscore the need for stricter monitoring of metal(loid) impurities in psychotropic drugs to protect patient safety and ensure regulatory compliance. Full article

Background: Coronary artery disease (CAD) is a multifactorial atherosclerotic disorder. Silicon (Si) is a trace mineral with potential antioxidant, anti-inflammatory, and lipid-modulating effects, but its clinical relevance in cardiovascular disease remains unclear. This study evaluated whether hair Si concentration—reflecting long-term exposure—is associated with CAD severity, clinical phenotype, risk factors, and systemic inflammation. Methods: A total of 130 patients with angiographically confirmed CAD (N = 36, 28% women) who met the inclusion criteria were enrolled. Disease severity was quantified using the Coronary Artery Surgery Study Score (CASSS) and SYNTAX score. Hair Si concentration was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Associations with demographic, clinical, biochemical, and inflammatory parameters were analyzed using non-parametric tests and multivariable ordinal logistic regression. Results: Median hair Si concentration was 21.3 ppm (range: 0.7–211.0). Hair Si levels showed no significant differences across CAD severity assessed by CASSS (H = 2.51; p = 0.47) or SYNTAX score (r = 0.079; p = 0.37). Similarly, no differences were observed between patients with stable angina and those presenting with acute coronary syndrome (p = 0.57) or between individuals with and without prior myocardial infarction. Hair Si concentration was unrelated to age, BMI, cardiovascular risk factors, lipid profile, or systemic inflammatory indices (all p > 0.2). Conclusions: Hair silicon concentration was not associated with CAD severity, phenotype, or systemic inflammation, suggesting that long-term Si exposure is metabolically neutral in advanced atherosclerosis. Unlike other minerals, silicon appears unlikely to serve as a diagnostic or prognostic biomarker in CAD, although its relevance may be confined to early vascular remodeling and primary prevention. Full article

Accurate analysis of trace elements in particulate matter (PM) emitted by brake systems critically depends on the filter selection and handling processes, which can significantly impact analytical results due to contamination and elemental interference from filter elemental composition. This study systematically evaluated two widely used filter types, EMFAB (borosilicate glass microfiber reinforced with PTFE) and Teflon (PTFE), for their suitability in the trace element determination of brake-wear PM₁₀ collected using a tribometer set-up. A total of twenty-three PM₁₀ samples were analyzed, encompassing two different friction materials, to thoroughly assess the performance and analytical implications of each filter type. Filters were tested for their chemical background, handling practicality and potential contamination risk through extensive elemental analysis by inductively coupled plasma–optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS). Additionally, morphological characterization of both filter types was conducted via scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) to elucidate structural features affecting particle capture and subsequent analytical performance. Significant differences emerged between the two filters regarding elemental interferences: EMFAB filters exhibited substantial background contribution, particularly for alkali and alkaline earth metals (Ca, Na, Mg and K), complicating accurate quantification at trace levels. Conversely, Teflon filters demonstrated considerably lower background but required careful manipulation due to their structural fragility and the necessity to remove supporting rings, potentially introducing analytical variability. Statistical analysis confirmed that the filter material significantly affects elemental quantification, particularly when the collected PM₁₀ mass is limited, highlighting the importance of careful filter selection and handling procedures. Recommendations for optimal analytical practices are provided to minimize contamination risks and enhance reliability in trace element analysis of PM₁₀ emissions. These findings contribute to refining analytical methodologies essential for accurate environmental monitoring and regulatory assessments of vehicular non-exhaust emissions. Full article

The objective of this work was to determine and compare a comprehensive set of quality markers, including main physicochemical properties and element profiles, in samples of Bulgarian oak honeydew honey (OHH) and coniferous honeydew honey (CHH). This investigation utilized a total of seventeen honey samples from Bulgaria harvested in 2022. The sample set comprised ten oak honeydew honey samples, sourced from the Burgas region, and seven coniferous honeydew honey samples obtained from the Smolyan region. The parameters of OHH samples varied within the following ranges: color (80–134 mm Pfund), water content (15.20–18.40%), electrical conductivity (0.80–1.33 mS/cm), specific optical rotation (2.25–12.50 ${\left[\alpha \right]}_D^{20}$), pH (3.92–4.50), total acidity (29.80–36.80 meq/kg), diastase activity (18.36–27.58 Gothe units), invertase activity (56–196 U/kg), proline content (155–477 mg/kg), and hydroxymethylfurfural (3.28–8.94 mg/kg). The CHH samples gave the following results: color (40–87 mm Pfund), water content (16.40–19.00%), electrical conductivity (0.80–1.26 mS/cm), specific optical rotation (−17.50–(−11.50 ${\left[\alpha \right]}_D^{20}$)), pH (3.40–3.75), total acidity (25.80–39.40 meq/kg), diastase activity (23.15–26.05 Gothe units), invertase activity (69–138 U/kg), proline content (287–651 mg/kg), and hydroxymethylfurfural (1.50–3.96 mg/kg). The elements Ca, Cu, Fe, Mg, and Mn were determined by Flame Atomic Absorption Spectrometer (FAAS), while Flame Atomic Emission Spectrometry (FAES) was used for K and Na determination. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analysis was used to assess six elements (Al, Ba, Co, P, Sr, Zn). The elements Cd, Ni, and Pb were determined by Electrothermal Atomic Absorption Spectrometry (ETAAS). Potassium is the most abundant macro element in all investigated samples ranging 2332–2370 µg/g in CHH and 1846–1878 µg/g in OHH. Other examined elements are in the following descending order, Mg > P > Na > Ca > Mn > Al > Fe > Zn > Cu > Ba > Sr, presenting in µg/g levels, while Pb > Ni > Co > Cd are present in µg/kg levels. This work constitutes the first report on the physicochemical parameters and chemical elements of coniferous honeydew honey from Bulgaria. Full article

Saltiness is a key characteristic that influences the quality of soy sauce. Currently, the evaluation of saltiness intensity in soy sauce relies on sensory evaluation methods, while a scientific and efficient model to quantify saltiness is lacking. Liquid chromatography–mass spectrometry (LC-MS) and inductively coupled plasma–optical emission spectrometry (ICP-OES) were used to analyze key taste compounds in 10 soy sauce samples. According to sensory evaluation and taste addition experiments, the model for assessing the saltiness intensity of soy sauce was established. The results indicate that the umami amino acid (aspartic acid, 2.44~15.30 mg/mL; glutamic acid, 8.29~67.94 mg/mL) and the nucleotides 5′-inosinic acid (0.44~12.5 mg/mL) and 5′-guanylic acid (0.41~2.51 mg/mL) mainly contributed the saltiness intensity of soy sauce through umami synergy. Pyroglutamic acid (19.6~79.22 mg/mL) and lactic acid (0.77~0.85 mg/mL) are the primary taste-contributing organic acids to balance the taste profile in soy sauce. The Na⁺ (54.6 mg/mL) and K⁺ (8.13 mg/mL) contents are both relatively high, directly affecting the saltiness of the soy sauce. Through Spearman’s correlation analysis, 11 key taste compounds were identified to construct a multiple linear regression prediction model for saltiness intensity. The model demonstrates excellent predictive performance, providing a theoretical basis and methodological support for objectively evaluating soy sauce saltiness and reducing salt content through a scientific approach. Full article

This study explores the bioleaching potential of indium from Liquid Crystal Display (LCD) screens originating from end-of-life mobile phones using Acidithiobacillus spp. The LCD panels were mechanically processed, including dismantling, crushing, and milling, and separated into four size fractions: <1 mm, 1–1.5 mm, 1.5–2 mm and >2 mm. These fractions were leached for a period of four weeks. During the experiment, changes in pH value were monitored, and the concentrations of indium in the solutions were measured by using inductively coupled plasma optical emission spectrometry (ICP-OES). The results showed that the highest indium was detected after 4 weeks of leaching for fraction FG <1 mm (146.47 mg/L). The study confirms that bioleaching is an effective and environmentally friendly method for the recovery of critical raw materials such as indium from electronic waste, offering a promising alternative to conventional chemical and pyrometallurgical techniques. Full article

This study evaluated regional and seasonal variations in cobalt (Co), cadmium (Cd), and lead (Pb) concentrations in the serum and milk of she-camels and their calves across five regions of Saudi Arabia to evaluate their potential as bioindicators of environmental contamination. A total of 450 biological and environmental samples (serum, milk, soil, water, and feed) were analyzed using inductively coupled plasma optical emission spectrometry (ICP–OES). Regional, seasonal, and physiological effects were assessed by analysis of variance and Pearson correlation. Serum Co varied significantly (p < 0.05) by region and season, with the highest values in the Eastern region during spring. She-camel cadmium showed significant regional differences, particularly higher concentrations in the Southern region, while Pb displayed pronounced seasonal variation, peaking in spring serum and milk of she-camel. In she-camel milk, Co, Cd, and Pb were significantly influenced by region and season interactions (p < 0.05). Correlation analysis revealed strong positive associations between Cd and Pb (r = 0.85, p < 0.001) and between Co and Pb (r = 0.70, p < 0.01), indicating shared exposure pathways. In conclusions, although all metal concentrations remained below FAO/WHO permissible limits, the observed variability highlights the camel’s value as a bioindicator of environmental contamination. Continued monitoring is recommended to safeguard food safety and support Saudi Vision 2030 sustainability goals. Full article

Cereal-based complementary foods are widely consumed by children, yet limited data exist on their elemental composition and potential health risks. This study quantified As, Cd, Co, Cr, Cu, Fe, K, Mn, Mg, Mo, Ni, P, Pb, Se, Si, V, and Zn in eight commercial cereal-based products collected in Campo Grande, Brazil, using inductively coupled plasma optical emission spectrometry (ICP OES). Arsenic, cadmium, cobalt, and chromium were consistently below the detection limit. Phosphorus and potassium were the predominant elements across brands, followed by Fe, Mg, and Zn, with significant inter-brand variability (Kruskal–Wallis, p < 0.05). Lead was detected in Brands 1–5 (0.11–0.41 mg/kg), but it was below the limit of detection (LOD = 0.003 mg/L) in the other samples. Estimated daily intake (DI) values at 30 g/day and 90 g/day showed that Fe, Zn, Mn, and Se frequently met or exceeded dietary reference intakes for children aged 1–3 years, while Cu, Ni, and P remained below tolerable levels. Comparison with tolerable upper intake levels and ATSDR minimal risk levels indicated that higher consumption (90 g/day) could result in excess intake of Mn, Zn, and Se, with Pb contributing to cumulative hazard indices above the safety threshold (HI > 1). These findings emphasize the dual role of cereal-based foods as important nutrient sources and potential contributors to excessive trace element exposure in young children. Full article

High-temperature sintering for ceramsite preparation is a safe and effective approach to recycle solid waste. Flux components are critical in ceramsite sintering, as they can reduce sintering temperature, modulate the viscosity and content of the liquid phase, and ultimately optimize ceramsite performance. However, existing studies on lead–zinc tailings (LZTs) and coal gangue (CG)-based ceramsite lack systematic exploration of key fluxes (Na₂O, MgO, CaO, Fe₂O₃), limiting the high-value utilization of these wastes. Under fixed sintering conditions (preheating at 400 °C for 30 min, sintering at 1250 °C for 30 min, heating rate of 10 °C/min), this work systematically investigated the effects of these fluxes (in the forms of carbonates, except for Fe₂O₃) on LZTs-CG ceramsite. The mechanical properties, mineral composition, microstructure and heavy metal leaching of samples were analyzed using various methods, including uniaxial compression, X-ray diffraction (XRD), scanning electron microscopy (SEM), and inductively coupled plasma optical emission spectrometry (ICP-OES). Results showed that, while Fe₂O₃ exerted a non-monotonic influence, Na₂O, MgO, and CaO improved apparent density and compressive strength, concurrently reducing water absorption, with these effects enhancing in a dose-dependent manner. Na₂O, MgO and Fe₂O₃ facilitated the formation of labradorite, cordierite and hematite, respectively. All fluxes weakened the diffraction peaks of quartz and mullite. ICP-OES results indicated that the fluxes slightly increased Pb and Zn leaching, yet the highest values (0.1975 mg/L for Pb, 0.0485 mg/L for Zn) were well below the limits specified in the Chinese national standard GB 5086.2-1997 (Leaching Toxicity of Solid Waste—Horizontal Vibration Extraction Procedure). This work shows optimized flux composition enables high-performance, eco-safe LZTs-CG ceramsite, supporting LZTs and CG high-value utilization and sustainable development. Full article

The great city of Mayapan has experienced a technological change in pottery making, and our results confirm a shift in the raw materials and possibly the potters’ knowledge about them. The dynamics of change during the Postclassic period in the Maya area are reflected in the material changes used to make pottery. A comprehensive analysis was conducted on a collection of 248 pottery items from the archaeological site of Mayapán in Yucatán, Mexico, dating from the Middle Preclassic to Postclassic periods (700 BC–1500 CE). Non-invasive methods were used for the entire pottery set, including X-ray fluorescence (XRF) and fiber-optic reflectance spectroscopy (FORS). Additionally, for a representative subset, minimally invasive techniques such as inductively coupled plasma optical emission spectrometry (ICP-OES) and laser-induced breakdown spectroscopy (LIBS) were employed. The resulting data enabled the identification of materials used in the pottery’s manufacture. The elemental composition of the objects was determined, revealing correlations between elements such as Si with Al that yield a $R^2$ factor of 0.94. The results indicate the presence of smectite clays, carbonates, and iron oxides. The results show that a higher proportion of carbonates was found in the pieces from the Postclassic period compared to those from the Preclassic period, which may be associated with a change in the manufacturing process. Likewise, the Postclassic pieces are distinguished by a greater contribution of the Mg-OH signal, unlike the Preclassic and Classic, which show a greater contribution of the Al-OH group. The implications for the technological knowledge of the potters suggest the use of different technologies across various periods and material changes driven by shifts in political and economic relations in the city and the northern plains. Full article

Trace metal pollution has become an increasing concern in urban areas, mainly due to industrial activities and heightened human activities near water bodies. This study aimed to quantify the level of pollution caused by the trace metals Co, Cr, Cu, Mn, Ni, and Zn in surface sediments of Aurá and Guamá rivers, as well as Guajará Bay, in the metropolitan region of Belém (Northern Brazil). A total of 33 sediment samples were collected—14 from the Aurá River, 7 from the Guamá River, and 12 from Guajará Bay—during both the wet and dry seasons to capture seasonal variability. The studied trace metals were measured through inductively coupled plasma optical emission spectrometry (ICP-OES), and the decreasing order of concentration detected was the following: Mn > Zn > Cr > Ni > Co > Cu. To assess the degree of pollution, three geochemical indicators were employed: the Geoaccumulation Index (Igeo), which compares observed concentrations with natural background levels to classify contamination severity; the Enrichment Factor (EF), which helps distinguish between natural and anthropogenic sources of metals using a reference element (typically aluminum or iron); and the Mean-ERM-Quotient, which evaluates the potential ecotoxicological risk of the metals based on benchmark values for adverse effects on aquatic organisms. Based on these indicators, the sediments of the studied area can be classified as showing “moderate contamination and enrichment”. The metals Zn and Cu exhibited the highest degrees of enrichment, likely of anthropogenic origin. Overall, this study revealed that areas closer to sites of intense human activity are more susceptible to trace metal contamination, especially during the wet season. Frequent monitoring of areas classified as “contaminated” and time-series data are necessary to examine more deeply the pollution of river sediments and their potential changes concerning shifts in the status of urbanization and industrialization. Full article

To investigate the geographical and species differences regarding mineral element content of camel milk, this research used camel milk from the Tacheng, Altay, and Ili regions of Xinjiang and cow milk, goat milk, and horse milk from the Tacheng region as subjects. The contents of 22 mineral elements were measured using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The results showed that the contents of macro elements Ca, P, K, and Na in camel milk were significantly higher than those in other milk sources (p < 0.01). The contents of trace elements such as Se, Sr, and Ni were very significantly higher than those in other milk sources (p < 0.01). The content of 12 mineral elements in camel milk was very significantly higher than in other types of milk (p < 0.01). Principal component analysis (PCA) and factor analysis emphasized the relationship between element distribution and different milk sources, and the linear discriminant analysis (LDA) model could identify the species type of milk. Geographical analysis indicated that trace elements such as Sr, Ni, and Cr were highly significantly enriched in Tacheng camel milk (p < 0.01). The established LDA model achieved traceability of the geographical origin of Xinjiang camel milk. This research reveals the mineral nutritional advantages of camel milk and its geographical differentiation patterns, providing theoretical support for exploring the functional properties of camel milk and for identifying species and regions through minerals. It is important to promote the upgrading of the specialty dairy product industry. Full article

Although approximately half of global lithium consumption is used in the rechargeable battery industry, lithium is also in demand for other specialized applications, such as high-temperature lubricants, ceramics, glass, and pharmaceuticals. The growing need for efficient lithium recovery and recycling underscores the importance of fast and accurate analytical tools for determining lithium concentrations in non-compliant and waste materials generated by industrial processes. In this paper, we present a machine learning-based procedure utilizing Laser-Induced Breakdown Spectroscopy (LIBS) to accurately quantify lithium concentrations in lithium-rich non-compliant materials derived from the industrial production of enamels used for coating metallic surfaces. This procedure addresses challenges such as strong self-absorption and matrix effects, which limit the effectiveness of conventional univariate calibration methods. By employing a multivariate approach, we developed a single model capable of quantifying lithium content across a wide concentration range. A comparison of the LIBS results with those obtained using conventional laboratory analysis (Inductively Coupled Plasma–Optical Emission Spectrometry, ICP-OES) confirms that LIBS can deliver the speed, precision, and reliability required for potential routine applications in the lithium recovery and recycling industry. Full article