Search Results (9,457)

Electronic waste (e-waste) is a growing solid waste stream with largely undisclosed and poorly characterized fluorinated constituents. We evaluated per- and polyfluoroalkyl substances (PFAS) leachability from four e-waste components (phone screens, phone plastics, capacitors, and Lithium-ion batteries) using a 30-day deionized water leaching test. PFAS were extracted by solid-phase extraction using weak anion exchange (WAX) cartridges and analyzed with a liquid chromatography triple-quadrupole mass spectrometer. In addition, the PFAS chemical profiles of e-waste components were characterized by non-targeted analysis. Leachable sums of detected PFAS (∑PFAS) were highest in phone screens (1739–1932 ng·kg⁻¹) and phone plastics (1575–2197 ng·kg⁻¹) and an order of magnitude lower in Lithium-ion batteries (148–158 ng·kg⁻¹) and capacitors (147–243 ng·kg⁻¹). Short-chain perfluoroalkyl acids (PFAAs) (e.g., PFBA, PFHxA) and legacy acids (e.g., PFOA, PFNA) were more prevalent in phone screens/plastics, whereas capacitors and batteries showed mixed sulfonate/carboxylate patterns (PFOS, PFHxS, and 6:2 FTS). Although capacitors and Lithium-ion batteries contained essential PFAS with high hazard potential at trace levels, phone screens and phone plastics pose a greater risk per mass due to higher ∑PFAS levels and larger volumes. Non-targeted analysis using Orbitrap Astral revealed CF₂/CF₂O homologous trends (confidence levels 2–3) with corroborating targeted findings. These findings highlight the need for PFAS-free alternatives, the disclosure of fluorinated additives, and stronger end-of-life management strategies to prevent PFAS releases from e-waste. Full article

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic chemicals used in daily life and industrial production. Due to their widespread use, these compounds are frequently detected in environmental samples. Many studies have shown that PFAS pose a significant threat to both ecological environments and human health, leading to widespread public concern. This study developed and optimized an analytical method for the detection of 32 common PFAS compounds in chemical additives and environmental samples, including oil displacement agents, groundwater and soil, utilizing High-Performance Liquid Chromatography–Quadrupole-Orbitrap High-Resolution Mass Spectrometry (HPLC–Q-Orbitrap HRMS) technology. Applications in an eastern Chinese oilfield revealed significant PFAS accumulation, with ∑PFAS concentrations in groundwater and soil at the well site ranging from 212.29 to 262.80 ng/L and from 23.70 to 71.65 ng/g, respectively, exceeding background levels by 10-fold. The oil displacement agents used in oilfields are one of the important sources of PFAS, particularly p-perfluorous nonenoxybenzenesulfonate (OBS), a perfluorooctanesulfonic acid (PFOS) substitute. Soil analysis indicated greater mobility of short-chain PFAS, while long-chain compounds adsorbed more readily to surface layers. Molecular docking and quantitative structure–property relationship (QSPR) modeling suggest that the bioaccumulation potential of OBS is high and comparable to that of PFOS. Zebrafish embryo assays demonstrated that OBS induced significant concentration-dependent cardiac developmental toxicity, including pericardial edema and apoptosis, showing 1.5–2.4 times greater toxicity than PFOS across multiple endpoints. These findings reveal OBS as a pervasive contaminant with elevated environmental and health risks, necessitating urgent re-evaluation of its use as a PFOS substitute. Full article

Reports of carbon monoxide (CO) pharmacology have spurred intense interest in developing its fluorescent probes with much success. However, one unfortunate event in this area is the wide-spread use of chemically reactive metal/BH₃-CO complexes as “CO-releasing molecules” or CORMs that do not produce CO or produce CO in an idiosyncratic fashion. Consequently, a large number of reported fluorescent “CO probes” only respond to the CORM used, but not to CO. Though most of these issues have been clarified in the literature, there is a surprising recent publication on a Cu(II)-based fluorescent “CO probe,” Nap-BC-Cu(II), relying on undefined chemical principles. We reassessed the ability for Nap-BC-Cu(II) to detect CO and found no evidence for Nap-BC-Cu(II) to selectively detect CO at even non-physiologically relevant high concentrations (high micromolar) of CO. Marginal effects were observed only when CO was continuously bubbled through the “probe” solution for 15 min. Further, Nap-BC-Cu(II) was found to be sensitive to ascorbic acid and cysteine. Overall, this probe did not respond to CO in a pathophysiologically relevant context. Our findings do not support the notion of Nap-BC-Cu(II) being a CO probe for studying CO biology. We hope this will be the last of this saga of “CO probes” that do not afford selective detection of CO, largely due to the confusions caused by using chemically reactive CORMs. Full article

This study evaluates the spatiotemporal variations in surface water quality in An Giang province, a key upstream region of the Vietnamese Mekong Delta (VMD), under the influence of hydrological alterations and climate change impacts. Water quality data from 2010 to 2023 were collected from 10 monitoring stations along the Tien and Hau Rivers, focusing on key parameters including pH, temperature, Dissolved Oxygen (DO), Total Suspended Solids (TSS), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Ammonium (N-NH₄⁺), Nitrate (NO₃⁻), orthophosphate (P-PO₄³⁻), and Coliforms. The Mann–Kendall test and Sen’s slope estimator were employed to detect long-term trends and quantify the magnitude of changes. The findings indicated that the Hau River exhibits significant organic pollution, evidenced by elevated levels of BOD and COD, alongside diminished levels of DO. The Tien River exhibits elevated concentrations of NH₄⁺ and total suspended solids (TSS). The MK test indicated that BOD, COD, and NH₄⁺ levels were increasing at most locations in a statistically significant manner. This indicates that the water quality deteriorated over time. The study revealed that the majority of pollutants exhibited statistically significant increasing trends (p ≤ 0.05). The Tien River’s COD is increasing by 1.6 mg/L annually, whereas the Hau River’s COD is escalating by 1.7 mg/L per year. The biochemical oxygen demand on both rivers is increasing by 0.5 mg/L each year. The diminishing quantities of dissolved oxygen indicated a decline in water quality. Pollutant concentrations demonstrated significant positive associations with maximum temperature (r = 0.47–0.64) and hours of sunshine (r ≈ 0.50–0.64). A significant negative correlation with river discharge was observed, particularly during the dry season (r = −0.79 to −0.88), when diminished flows resulted in elevated pollution concentrations. The findings offer measurable evidence that increasing temperatures and decreasing river flows significantly affect water quality, underscoring the necessity of adapting water resource management in the Mekong Delta. Full article

The non-destructive and chemical-free determination of anthocyanin content in single maize kernels is of great importance for plant-breeding programs. Previous studies have mainly relied on Near-Infrared Reflectance (NIR) spectroscopy and color-based approaches, often using conventional or randomly selected modeling techniques. In this study, an Automated Machine Learning (AutoML) framework was employed to predict anthocyanin content using spectral and digital image data obtained from individual maize kernels measured in two orientations (embryo-up and embryo-down). Forty colored maize genotypes representing diverse phenotypic characteristics were analyzed. Digital images were acquired in RGB, HSV, and LAB color spaces, together with NIR spectral data, from a total of 200 kernels. Reference anthocyanin content was determined using a colorimetric method. Ten datasets were constructed by combining different color space and spectral features and were grouped according to kernel orientation. AutoML was used to evaluate nine machine learning algorithms, while Partial Least Squares Regression (PLSR) served as a classical benchmark method, resulting in the development of 1918 predictive models. Kernel orientation had a notable effect on model performance and outlier detection. The best predictions were obtained from the RGB dataset for embryo-up kernels and from the combined RGB+HSV+LAB+NIR dataset for embryo-down kernels. Overall, AutoML outperformed conventional modeling by automatically identifying optimal algorithms for specific data structures, demonstrating its potential as an efficient screening tool for anthocyanin content at the single-kernel level. Full article

This study investigates the technological and chemical causes of early zinc-coating degradation on cold-formed steel sections produced from DX51D+Z140 galvanized coils. Commercially manufactured products exhibiting early corrosion symptoms were used in this study. The entire processing route, which included strip preparation, cold rolling, hot-dip galvanizing, passivation, multi-roll forming, storage, and transportation to customers, was analyzed with respect to the residual surface chemistry and process-related deviations that affect the coating integrity. Thirty-three specimens were examined using electromagnetic measurements of coating thickness. Statistical analysis based on the Cochran’s and Fisher’s criteria confirmed that the increased variability in zinc coating thickness is associated with a higher susceptibility to localized corrosion. Surface and chemical analysis revealed chloride contamination on the outer surface, absence of detectable Cr(VI) residues indicative of insufficient passivation, iron oxide inclusions beneath the zinc coating originating from the strip preparation, traces of organic emulsion residues impairing wetting and adhesion, and micro-defects related to deformation during roll forming. Early zinc coating degradation was shown to result from the cumulative action of multiple technological (surface damage during rolling, variation in the coating thickness) and environmental (moisture during storage and transportation) parameters. On the basis of the obtained results, a methodology was proposed to prevent steel product corrosion in industrial conditions. Full article

Dysphania ambrosioides is a widely distributed species with a traditional use in folk medicine, but it exhibits marked chemical variability that limits its standardization. This study is the first to characterize the essential oil (EO) of three Ecuadorian populations—Arenillas (ARE), Pasaje (PAS) and Piñas (PIN)—using gas chromatography–mass spectrometry/flame ionization detection (GC-MS/FID), and to correlate its composition with edaphic properties and antioxidant activity. Chemical profiles revealed three distinct chemotypes: ARE (α-terpinene 65.35%, o-cymene 24.83% and ascaridole 3.30%), PAS (α-terpinene 56.31%, o-cymene 10.09% and ascaridole 10.84%) and PIN (α-terpinene 56.89%, o-cymene 17.07% and ascaridole 7.60%). The EO yield was low (0.030–0.064% w/w), coinciding with acidic and nutrient-poor soils. On the other hand, PAS, with its neutral soil and high nitrogen, produced the highest number of oxygenated compounds. Only PAS exhibited strong ABTS radical-scavenging activity (SC₅₀ = 37.99 ± 1.01 µg/mL). In contrast, ARE showed weak activity (SC₅₀ = 424 ± 1.01 µg/mL), while PIN showed moderate activity (SC₅₀ = 112.26 ± 1.01 µg/mL), which was correlated with its high total phenol content (298.48 mg EAG/L). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity was low in all samples. Principal component analysis (PCA) confirmed clear separation of the chemotypes, which was linked to edaphic factors such as pH, heavy metals (Cu, Fe and Mn) and organic matter. These findings suggest that edaphic conditions may modulate the chemical composition and antioxidant activity of D. ambrosioides, indicating a potential approach for the sustainable selection of plant material. Full article

We aimed to establish a rapid and precise method for identifying and quantifying multi-species vegetable oil (corn oil, olive oil (OLO), soybean oil, and sunflower oil (SUO)) adulterations in camellia oil (CAO), using soft ionization by chemical reaction in transfer–high-resolution mass spectrometry (SICRIT-HRMS) and machine learning methods. The results showed that SICRIT-HRMS could effectively characterize the volatile profiles of pure and adulterated CAO samples, including binary, ternary, quaternary, and quinary adulteration systems. The low m/z region (especially 100–300) exhibited importance to oil classification in multiple feature-selection methods. For qualitative detection, binary classification models based on convolutional neural networks (CNN), Random Forest (RF), and gradient boosting trees (GBT) algorithms showed high accuracies (98.70–100.00%) for identifying CAO adulteration under no dimensionality reduction (NON), principal component analysis (PCA), and uniform manifold approximation and projection (UMAP) strategies. The RF algorithm exhibited relatively high accuracy (96.25–99.45%) in multiclass classification. Moreover, the five models, including CNN, RF, support vector machines (SVM), logistic regression (LR), and GBT, exhibited different performances in distinguishing pure and adulterated CAO. Among 1093 blind oil samples, under NON, PCA, and UMAP: 10, 5, and 67 samples were misclassified by CNN model; 6, 7, and 41 samples were misclassified by RF model; 8, 9, and 82 samples were misclassified by SVM model; 17, 18, and 78 samples were misclassified by LR model; 7, 9, and 43 samples were misclassified by GBT model. For quantitative prediction, the PCA-CNN model performed optimally in predicting adulteration levels in CAO, especially with respect to OLO and SUO, exhibiting a high coefficient of determination for calibration ($R_C^2$, 0.9664–0.9974) and coefficient of determination for prediction ($R_p^2$, 0.9599–0.9963) values, low root mean square error of calibration (RMSEC, 0.9–5.3%) and root mean square error of prediction (RMSEP, 1.1–5.8%) values, and RPD (5.0–16.3) values greater than 3.0. These results indicate that SICRIT-HRMS combined with machine learning can rapidly and accurately identify and quantify multi-species vegetable oil adulterations in CAO, which provides a reference for developing non-targeted and high-throughput detection methods in edible oil authenticity. Full article

Fluorinated colloidal nanosystems have attracted significant attention for their advantageous properties and potential applications in the biomedical field, especially in ¹⁹F magnetic resonance imaging. These nanosystems are known for their high specificity, excellent biocompatibility, and ease of functional modification. Furthermore, they offer unique advantages for functional surface coating due to their surface performance and chemical resistance. This paper discusses recent developments in fluorinated colloidal nanosystems, including applications in biological detection (such as enzymes, proteins, pH levels, ions, reducing environments, and reactive oxygen species) and surface coating (such as self-cleaning, self-healing, antibacterial properties, anti-fogging, antifouling, and oil–water separation). This article also highlights current challenges and provides suggestions for future research directions in the field of fluorinated colloidal nanosystems. Full article

This study investigated the chemical composition, antioxidant activity, and genotoxic potential of essential oils (EOs) obtained by hydrodistillation from aerial parts of four wild-growing Lamiaceae species in eastern Morocco: Spanish ziziphora (Ziziphora hispanica L.), felty germander (Teucrium polium L.), French lavender (Lavandula dentata L.), and topped lavender (Lavandula stoechas L.). Gas chromatography–mass spectrometry (GC-MS) analysis revealed eucalyptol (40.08%), thujopsene (11.25%), β-myrcene (15.82%), and fenchone (30.69%) as the major constituents in Z. hispanica, T. polium, L. dentata, and L. stoechas, respectively. Antioxidant capacity was evaluated using three complementary assays: 2,2-diphenyl-1-picrylhydrazyl radical scavenging, ferric reducing antioxidant power, and β-carotene bleaching. L. stoechas and L. dentata exhibited the strongest antioxidant activities, with IC₅₀ values ranging from 0.284 to 1.71 mg/mL across assays. Genotoxicity was assessed in rat leukocytes using the alkaline Comet assay at EO concentrations of 2.5, 5, and 10 µg/mL. All tested EOs induced statistically significant DNA damage compared to the negative control, though the extent varied by species and concentration; notably, L. stoechas at 2.5 µg/mL showed the lowest genotoxic impact. These findings highlight the dual potential of these EOs as natural antioxidants while underscoring the need for dose-dependent safety evaluation prior to therapeutic or industrial application. Given that DNA damage was detectable even at 2.5 µg/mL, a conservative practical recommendation is to keep EO levels below 2.5 µg/mL-equivalent in preliminary applications, pending further in vivo toxicology to establish NOAEL-based exposure limits. Full article

Volatile organic compounds (VOCs) play a central role in plant communication and ecology, acting as a chemical language that mediates interactions with other organisms and responses to environmental stimuli. Analyzing changes in the plant volatilome enables the effective differentiation between biotic and abiotic stresses. Consequently, monitoring VOC emissions offers valuable insights into plant signaling pathways and health status. These insights position this approach as a promising strategy for improving crop protection. Direct infusion (DI) online analytical techniques, such as proton transfer reaction mass spectrometry (PTR-MS) and adduct ionization mechanism mass spectrometry (AIM-MS), have been developed to detect and characterize VOCs in real time. Here, we evaluated the suitability of PTR-MS and AIM-MS for monitoring VOC emissions in pea plants (Pisum sativum L.). Comparative analysis revealed that AIM-MS, a recently developed technology, detected a higher number of distinct signals than PTR-MS. Annotation of detected and significant AIM-MS signals indicated a predominance toward those that were putative lipids-derived and amino acids-derived, whereas PTR-MS signals were primarily associated with putative phenolic compounds. These findings suggest that the newly developed AIM reactor offers a broader detection range and may enhance our ability to monitor plant VOC emissions. Consequently, AIM-MS emerges as a promising tool for the real-time assessment of pea plant health and stress responses. Further efforts are needed to improve the portability of DI-MS techniques and to integrate them with GC-MS techniques. Overall, these efforts will allow this technology to be exploited for plant protection in compromised environments. Full article

The continuous detection of emerging pollutants (EPs) in water poses potential threats to aquatic environmental safety and human health, and their efficient removal is a frontier in environmental engineering research. This review systematically summarizes research progress from 2005 to 2025 on the application of activated carbon (AC) and its composites for removing EPs from water and analyzes the development trends in this field using bibliometric methods. The results indicate that research has evolved from the traditional use of AC for adsorption to the design of novel materials through physical and chemical modifications, as well as composites with metal oxides, carbon-based nanomaterials, and other functional components, achieving high adsorption capacity, selective recognition, and catalytic degradation capabilities. Although AC-based materials demonstrate considerable potential, their large-scale application still faces challenges such as cost control, adaptability to complex water matrices, material regeneration, and potential environmental risks. Future research should focus on precise material design, process integration, and comprehensive life-cycle sustainability assessment to advance this technology toward highly efficient, economical, and safe solutions, thereby providing practical strategies for safeguarding water resources. Full article

The main objective of this research was to evaluate the seasonal variability of PM₁₀-bound polycyclic aromatic hydrocarbons (PAHs), their sources, and analyse their health impacts We confirmduring the COVID-19 pandemic period. The chemical composition of PM₁₀ in terms of PAH content was carried out using the gas chromatography-mass spectrometry (GC-MS) technique. PM₁₀ samples were collected in Krakow from 2020 to 2021. A total of 92 samples of particulate matter (PM₁₀ fraction) were analysed. The analyses contained 16 basic PAHs identified by the United States Environmental Protection Agency (U.S. EPA) as the most harmful. The information obtained on the concentrations of PAHs was used to determine the profiles of pollution sources, exposure profiles, and the values of toxic equivalency factors recommended by the EPA: mutagenic equivalent to B[a]P (ang. mutagenic equivalent, MEQ), toxic equivalent to B[a]P (ang. toxic equivalent, TEQ), and carcinogenic equivalent to 2,3,7,8-tetrachlorodibenzo-p-dioxin (ang. carcinogenic equivalent, CEQ). In Kraków, heavy PAHs accounted for over 90% of the total PAHs detected in the PM₁₀ samples. In addition, air trajectory frequency analysis was performed to obtain information on the possibility of transporting pollutants from selected areas in the vicinity of the studied site. Interpreting the trajectory results provided information on the nature of air pollution sources. Analysis of Kraków’s air mass trajectory showed that the highest daily concentration of PM₁₀ in the air flow was from the southwest and east for days. Full article

The red imported fire ant, Solenopsis invicta Buren, is a eusocial insect that relies on a sophisticated chemical communication system for colony organization and function. Its olfactory system is vital for detecting semiochemicals in the environment. This study utilized single sensillum recording (SSR) to assess the olfactory neuronal responses of female alates and workers from basiconica sensilla exposed to a panel of 62 individual pheromones and general odorants, including terpenes, terpenoids, pyrazines, pyridines, ketones, aldehydes, alcohols, acids, aliphatic and aromatic acetates, benzoates, benzyl esters, and three essential oils. Basiconica sensilla, which contain multiple olfactory receptor neurons (ORNs), exhibited moderate to strong responses to most of the tested compounds, demonstrating a broad sensitivity to all odorants elevated. Comparative analysis of the two castes revealed that ORNs had similar responses to 47 odorants; however, workers showed stronger responses to nine specific compounds, while female alates responded more strongly to six others. These differences underscore the caste-specific olfactory tuning, likely reflecting their distinct roles within the colony. This study presents the first comprehensive mapping of basiconica sensilla responses to general odorants in S. invicta female alates and workers, enhancing our understanding of the S. invicta chemical ecology and potentially contribute to more effective fire ant management strategies. Full article

This study investigated the phytochemical composition and biological activity of Cymbopogon citratus microshoot cultures and evaluated their suitability for incorporation into a cosmetic formulation. Microshoot cultures were established on Murashige and Skoog media supplemented with plant growth regulators and served as a reproducible source of biomass. Methanolic and ethanolic extracts were analyzed for total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Chemical composition was characterized using LC-MS/MS analysis, which revealed the presence of phenolic acids and flavonoids, with p-coumaric, caffeic, and ferulic acids being among the most abundant detected constituents. In biological assays, the extracts inhibited murine tyrosinase in a concentration-dependent manner and exhibited antimicrobial activity against selected oral and skin-associated microorganisms, including Streptococcus mutans, Streptococcus pyogenes, and Staphylococcus epidermidis, as well as showing fungistatic and fungicidal effects against Candida albicans. Cytotoxicity analysis performed on HaCaT keratinocytes confirmed biocompatibility within the tested concentration range. To assess formulation suitability, the microshoot extract was incorporated into an oil-in-water (O/W) cream, which maintained stable pH, viscosity, and physical properties while preserving the antioxidant activity of the extract. Overall, these findings indicate that C. citratus microshoot cultures represent a reproducible source of bioactive metabolites with potential application in cosmetic formulations. Full article