Search Results (197)

The demand for rapid, energy-efficient, and low-toxicity methods for synthesizing molecularly imprinted polymers (MIPs) is increasing, particularly for applications in environmental monitoring and green chemistry. In this context, the present work focuses on the development of a novel laser-assisted method for MIP synthesis, employing a visible laser (450 nm) and erythrosine B as a green photoinitiator. This visible-light approach enables fast and spatially controlled polymerization while avoiding the drawbacks of conventional methods (thermal heating, UV synthesis), such as the use of toxic initiators like AIBN and the need for UV shielding. MIPs were synthesized for bisphenol A and sulfamethoxazole, two emerging contaminants of significant environmental concern. The synthesis process was optimized for rapidity and scalability, and the resulting MIPs were integrated into a paper-based analytical device (MIP-PAD) for smartphone-assisted, on-site detection. The developed sensors exhibited excellent analytical performance, with recovery rates of 98.6% in tap water and 90.2% in river water and relative standard deviations (RSDs) below 1.88%. This study demonstrated a green, efficient, and highly controllable laser-assisted polymerization technique, offering a promising alternative to conventional MIP synthesis methods. Full article

An environmentally friendly and highly sensitive analytical method for the determination of the dye Eosin Y (EY) was developed utilizing vortex-assisted liquid–liquid microextraction based on deep eutectic solvents (DESs), combined with fluorescence detection (LPME-FLD). The extraction efficiencies of conventional solvents and various DES systems, composed of tetrabutylammonium bromide (TBAB) and alcohols (hexanol, octanol, and decanol) in different ratios, were systematically compared. DFT calculations provided insights into the most stable forms of EY in solvents of varying polarity. Theoretical Hansen solubility parameters and the COSMO-RS solvation model were applied to assess extraction efficiency. Hansen parameters were obtained via semiempirical PM7 calculations, while BP86/def2-TZVPD DFT computations were employed within the openCOSMO-RS framework. The developed method exhibited a linear calibration range between 0.1 and 130 µg·L⁻¹, with a high correlation coefficient (R² = 0.9982). The limit of detection (LOD) was established at 0.028 µg·L⁻¹. Method precision and repeatability were confirmed over two days, with relative standard deviations (RSDs) ranging from 1.1% to 2.7% and with recoveries between 99.0% and 106.2%. The proposed analytical approach was successfully applied to the determination of EY in real water samples, demonstrating both its practical applicability and alignment with green chemistry principles. Full article

Narcotics trafficking is a fundamental part of organized crime, posing significant and evolving challenges for forensic investigations. Addressing these challenges requires rapid, precise, and scientifically validated analytical methods for reliable identification of illicit substances. Over the past five years, forensic drug testing has advanced considerably, improving detection of traditional drugs—such as tetrahydrocannabinol, cocaine, heroin, amphetamine-type stimulants, and lysergic acid diethylamide—as well as emerging new psychoactive substances (NPS), including synthetic cannabinoids (e.g., 5F-MDMB-PICA), cathinones (e.g., α-PVP), potent opioids (e.g., carfentanil), designer psychedelics (e.g., 25I-NBOMe), benzodiazepines (e.g., flualprazolam), and dissociatives (e.g., 3-HO-PCP). Current technologies include colorimetric assays, ambient ionization mass spectrometry, and chromatographic methods coupled with various detectors, all enhancing accuracy and precision. Vibrational spectroscopy techniques, like Raman and Fourier transform infrared spectroscopy, have become essential for non-destructive identification. Additionally, new sensors with disposable electrodes and miniaturized transducers allow ultrasensitive on-site detection of drugs and metabolites. Advanced chemometric algorithms extract maximum information from complex data, enabling faster and more reliable identifications. An important emerging trend is the adoption of green analytical methods—including direct analysis, solvent-free extraction, miniaturized instruments, and eco-friendly chromatographic processes—that reduce environmental impact without sacrificing performance. This review provides a comprehensive overview of innovations over the last five years in forensic drug analysis based on the ScienceDirect database and highlights technological trends shaping the future of forensic toxicology. Full article

The widespread discharge of industrial and urban waste has led to significant increases in the environmental concentrations of numerous chemical substances. This work presents the development of a simple and environmentally friendly dispersive liquid–liquid microextraction (DLLME) method based on a hydrophobic natural deep eutectic solvent (NADES) for the determination of selected compounds from benzotriazole, benzothiazole, paraben, and UV filter families in wastewater samples. Of the twelve NADES formulations evaluated, those composed of a 4:1 molar ratio of thymol and menthol presented the highest extraction efficiencies. The influence of key experimental variables such as the pH of the aqueous sample, the ratio of NADES phase to sample volume, and the extraction time on the extraction efficiency was investigated using a multivariate optimization. Under optimal conditions, relative standard deviations below 15% and recoveries for spiked wastewater samples ranged between 82 and 108%, demonstrating the suitability of the method for routine water-quality monitoring. The sustainability and practicality of the developed method was evaluated using the assessment tools ChlorTox, AGREEprep, AGRRE, and BAGI, obtaining scores of 0.005 g in the NADES-DLLME method, 0.70, 0.52, and 72.5, respectively, demonstrating that the method is green and reliable. Full article

A simple and fast analytical method was developed and applied to assess the effect of two forms of zinc fertilization on a pecan tree cultivar in Uruguay: fertigation and foliar application with a specially formulated fertilizer. Zinc content was determined in 36 leaf samples from two crop cycles: 2020–2021 and 2021–2022. Fresh samples were dried, ground, and sieved. Analytical determinations were performed by flame atomic absorption spectrometry (FAAS, considered a standard method) and energy dispersive X-ray spectrometry (EDXRF, the proposed method). In the first case, sample preparation was carried out by microwave-assisted digestion using 4.5 mol L⁻¹ HNO₃. In the second case, pellets (Φ 13 mm, 2–3 mm thick) were prepared by direct mechanical pressing. Figures of merit of both methodologies were adequate for the purpose of zinc monitoring. The results obtained from both methodologies were statistically compared and found to be equivalent (95% confidence level). Based on the principles of Green Analytical Chemistry, both procedures were evaluated using the Analytical Greenness Metric Approach (AGREE and AGREEprep) tools. It was concluded that EDXRF was notably greener than FAAS and can be postulated as an alternative to the standard method. The information emerging from the analyses aided decision-making at the agronomic level. Full article

Biosurfactants have emerged as promising agents for environmental remediation due to their ability to complex, chelate, and remove heavy metals from contaminated environments. This review evaluates their potential for recovering critical minerals from waste materials to support renewable energy production, emphasizing the role of biosurfactant–metal interactions in advancing green recovery technologies and enhancing resource circularity. Among biosurfactants, rhamnolipids demonstrate a high affinity for metals such as lead, cadmium, and copper due to their strong stability constants and functional groups like carboxylates, with recovery efficiencies exceeding 75% under optimized conditions. Analytical techniques, including Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Fourier-Transform Infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM), are instrumental in assessing recovery efficiency and interaction mechanisms. The review introduces a Green Chemistry Metrics Framework for evaluating biosurfactant-based recovery processes, revealing 70–85% lower Environmental Factors compared to conventional methods. Significant research gaps exist in applying biosurfactants for extraction of metals like lithium and cobalt from batteries and other waste materials. Advancing biosurfactant-based technologies hold promise for efficient, sustainable metal recovery and resource circularity, addressing both resource scarcity and environmental protection challenges simultaneously. Full article

Milk of lime (MOL), a suspension of calcium oxide and calcium hydroxide, is vital in the purification of sugar beet and cane juices. This study evaluates the application of Fourier Transform Near-Infrared (FT-NIR) spectroscopy combined with chemometric models—Partial Least Squares (PLS) and Principal Component Regression (PCR)—for rapid, non-destructive assessment of key MOL parameters: density, total lime content, calcium oxide availability, and sucrose content. Ninety samples were analyzed using both wet chemistry and FT-NIR. The predictive performance was assessed using the coefficient of determination (R²). High predictive accuracy was observed for density (PLS: R² = 0.8274; PCR: R² = 0.8795) and calcium oxide availability (PLS: R² = 0.9035; PCR: R² = 0.9115). Total lime content showed moderate accuracy (PLS: R² = 0.7748; PCR: R² = 0.7983), while sucrose content exhibited low predictive power (PLS: R² = 0.2312; PCR: R² = 0.3747). The weak performance was noted for %CaO (PLS: R² = 0.4893; PCR: R² = 0.2409), likely due to spectral overlap and matrix complexity. Despite these challenges, FT-NIR remains a viable, reagent-free method for monitoring MOL, with the potential to enhance process control in the sugar industry. Future work should focus on refining calibration strategies and addressing spectral interferences to improve predictive accuracy for complex matrices. Full article

We propose a hierarchical federated learning (HFL) framework for predictive pollutant analysis in advanced green analytical chemistry (AGAC), addressing the limitations of centralized approaches in scalability and data privacy. The system integrates localized sub-models with hybrid neural architectures, combining LSTM and attention mechanisms to capture temporal dependencies and feature importance in distributed analytical data, while raw measurements remain decentralized. A global aggregator dynamically adjusts model weights based on validation performance and data heterogeneity, ensuring robust adaptation to diverse environmental conditions. The framework interfaces seamlessly with AGAC infrastructure, processing inputs from analytical instruments into standardized sequences and mapping predictions back to pollutant concentrations through calibration curves. Implemented with PyTorch Federated and edge-cloud deployment, the system employs homomorphic encryption for secure data transmission, prioritizing spectral features critical for organic pollutant detection. Our approach achieves superior accuracy and privacy preservation compared to traditional centralized methods, offering a transformative solution for scalable environmental monitoring. The proposed method demonstrates significant potential for real-world applications, particularly in scenarios requiring distributed data collaboration without compromising analytical integrity. Full article

The growing demand for rare earth elements (REEs) in high-tech and green energy sectors has prompted renewed exploration of unconventional sources. Drill cuttings, which are commonly discarded during subsurface drilling, are increasingly recognized as a potentially valuable, underutilized secondary REE reservoir. This review adopts a mineral-first lens to assess REE occurrence, extractability, and recovery strategies from drill cuttings across various lithologies. Emphasis is placed on how REEs associate with specific mineral host phases ranging from ion-adsorbed clays and organically bound forms to structurally integrated phosphates, each dictating distinct leaching pathways. The impact of drilling fluids on REE surface chemistry and mineral integrity is critically examined, alongside an evaluation of analytical and extraction methods tailored to different host phases. A scenario-based qualitative techno-economic assessment and a novel decision-tree framework are introduced to align mineralogy with optimal recovery strategies. Limitations in prior studies, particularly in characterization workflows and mineralogical misalignment in leaching protocols, are highlighted. This review redefines drill cuttings from industrial waste to a strategic resource, advocating for mineralogically guided extraction approaches to enhance sustainability in the critical mineral supply chain. Full article

Traditional methods of synthesizing nanoparticles often rely on physical and chemical processes using synthetic hazardous chemicals. In contrast, the rise in green chemistry emphasizes using bioactive compounds from plants for the eco-friendly synthesis of nanostructures. These green synthesis techniques are increasingly recognized for their simplicity, cost-effectiveness, and ability to yield non-toxic by-products, an approach that aligns with sustainable practices. In this research, a straightforward, cheap, environmentally friendly, and sustainable procedure was developed to fabricate Zinc oxide nanoparticles (ZnO-NPs) employing three different pulp extracts: Agave (Agave americana), Chiku (Manilkara zapota), and Soursop (Annona muricata) to serve in the synthesis as capping, reduction, or stabilization agent. Analytical characterization techniques confirmed the successful phytosynthesis of ZnO-NPs, evidenced by significant absorbance peaks of UV-Vis spectra at 362 nm, and the chemical composition of ZnO without noticeable traces of phytochemical residues by carrying out ATR-FTIR analysis. SEM, STEM microscopies, and XRD analysis verified that the ZnO nanoparticles possess spherical geometries and hexagonal crystal structures. The average size of these nanoparticles was around 15.94, 18.08, and 23.32 nm for Agave, Chiku, and Soursop extract-based synthesis, respectively. Additionally, the in vitro antibacterial activity of phytosynthetized ZnO-NPs was evaluated against E. coli and S. aureus, confirming effective bacterial growth inhibition and demonstrating their significant antimicrobial potential. Full article

In this review, a 5-year overview on environmentally friendly approaches for the extraction of the most relevant organic pollutants in soil, sediment, particulate matter, and sewage sludge coupled with chromatographic analysis is reported. Organic contaminants encompass various compounds derived from personal care products, industrial chemicals, microplastics, organic matter combustion, agricultural practices, and plasticizer material. The principles of green analytical chemistry (GAC) and green sample preparation (GSP) serve as a guideline for the development of more environmentally sustainable analytical protocols. This study focuses attention on microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), matrix solid-phase dispersion (MSPD), and microextraction techniques, such as solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE), hollow-fiber liquid-phase microextraction (HF-LPME), spray-assisted droplet formation-based liquid-phase microextraction (SADF-LPME), and dispersive liquid–liquid extraction (DLLME). These approaches represent the most relevant eco-friendly sample preparation for the advanced extraction of target analytes from environmental solid samples. Full article

A novel method for the spectrophotometric determination of trace amounts of molybdenum has been developed. This method utilizes a centrifuge-less cloud point extraction (CL-CPE) in a mixed micellar (MM) system containing a nonionic surfactant (Triton X-114) and an ionic liquid (Aliquat^® 336, A336). The chromophore chelating reagent employed was 4-nitrocatechol (4NC, H₂L). This work marks its first application as a CPE reagent. Under the optimal conditions, Mo(VI) forms a yellow ternary complex with 4NC and A336, which can be represented by the formula (A336⁺)₂[MoO₂L₂]. The method possesses the following characteristics: limit of detection (LOD) of 3.2 ng mL⁻¹, linear range of 10.8–580 ng/mL, absorption maximum of 435 nm, molar absorptivity coefficient of 3.34 × 10⁵ L mol⁻¹ cm⁻¹, and Sandell’s sensitivity of 0.29 ng cm⁻². The method has been successfully employed for the determination of molybdenum in reference standard steel samples, bottled mineral water, and a molybdenum-containing dietary supplement. Full article

Metal-doped carbon dots (CDs) have become one of the most popular catalytic materials for Fenton-like reactions, mainly due to their low production cost, minimal toxicity, and high catalytic efficiency. Theses reactions not only provide an efficient decontamination method for the degradation of organic pollutants in wastewater but also demonstrate a wide range of sensing applications. Metal doping introduces new catalytically active centres, which increase the binding selectivity to the reactants and offer an additional advantage of improved catalytic degradation and sensing activity. The metal-doped CDs optimise the electronic structure of pristine CDs, thereby enhancing their catalytic properties and reaction rates. These enhancements make them an attractive option for water treatment and sensor design. The objective of this review is to provide a comprehensive overview of the current research progress in the utilisation of metal-doped CDs as Fenton-like reaction catalysts for the degradation of pollutants and sensing applications. This review examines the advantages of metal-doped carbon dots in terms of catalytic efficiency, selectivity, and application scope and discusses the potential challenges and future research directions. The aim is to promote further the sustainable application and green development of CD technology in environmental governance and analytical chemistry. Full article

A novel design for vortex-assisted liquid–liquid microextraction (VALLME), combined with spectrofluorimetric determination (FLD), was proposed and successfully tested for determining picric acid (PA) in water samples. This fluorescence method is based on the formation of an ion associate (IA) through electrostatic interactions, which serves as the analytical species for fluorescence measurement in the presence of the basic polymethine dye Astrafloksin (AF). The approach aims to minimize the volume of the extraction phase, aligning with the principles of green analytical chemistry. The calibration curve was linear from 0.92 to 11.45 µg L⁻¹, with an R² of 0.9930. LOD was 0.40 µg L⁻¹. Density functional theory (DFT) calculations, supported by analysis of van der Waals and electrostatic interionic attraction, helped explain the experimentally observed selectivity of the AF cation for picrate compared to other selected phenols. Theoretical solubility descriptors of the proposed IA provided insight into the extraction of IA from water to the n-amyl acetate phase. This VALLME-FLD method represents a significant advancement in PA determination, characterized by high sensitivity, selectivity, and procedural simplicity. It minimizes the use of organic solvents, facilitates direct sample preparation, and shortens analysis time. The developed method was successfully applied to real samples. Full article

Carotenoids are essential bioactive compounds in plant-based foods, valued for their antioxidant properties and role in human health. Accurate quantification of these pigments is critical for food science, nutrition, and health research, yet their analysis remains challenging due to structural complexity, susceptibility to degradation, and matrix interferences. This review comprehensively evaluates analytical techniques for carotenoid assessment, focusing on chromatographic advancements, emerging detection strategies, and sustainability considerations. High-performance liquid chromatography remains the gold standard due to its precision, while novel approaches such as supercritical fluid chromatography and core–shell particle technology enhance efficiency and environmental sustainability. Machine learning and lab-on-a-chip technologies are also emerging as promising tools for rapid, cost-effective, and miniaturized analysis. Challenges in standardization, regulatory gaps, and the limited availability of certified reference materials persist, emphasizing the need for fully validated analytical methodologies. Future research should prioritize green analytical techniques and interdisciplinary strategies to improve sensitivity, reproducibility, and environmental impact. This review provides a critical resource for researchers and industry professionals willing to refine carotenoid analysis for food science, nutrition, and biotechnology applications. Full article