Search Results (73)

Superhydrophobic magnetic nanomaterials (SHMNMs) are emerging as multifunctional platforms for efficient oil–water separation due to their combination of extreme water repellency, strong oil affinity, and external magnetic responsiveness. This review presents a comprehensive analysis of recent advances in the design, synthesis, and environmental application of SHMNMs. The theoretical foundations of superhydrophobicity and the physicochemical behavior of magnetic nanoparticles are first outlined, followed by discussion of their synergistic integration. Key fabrication techniques—such as sol–gel synthesis, electrospinning, dip-coating, laser-assisted processing, and the use of biomass-derived precursors—are critically assessed in terms of their ability to tailor surface morphology, chemical functionality, and long-term durability. The review further explores the mechanisms of oil adsorption, magnetic separation, and material reusability under realistic environmental conditions. Special attention is paid to the scalability, mechanical resilience, and environmental compatibility of SHMNMs in the context of water treatment technologies. Current limitations, including reduced efficiency in harsh media, potential environmental risks, and challenges in material regeneration, are discussed. This work provides a structured overview that could support the rational development of next-generation superhydrophobic materials tailored for sustainable and high-performance separation of oil and organic pollutants from water. Full article

This study presents a sustainable approach to recycling exhausted etching solutions through ferritization, using various activation methods and aeration rates. The process transforms industrial waste into valuable magnetic sorbents, supporting circular economy principles. Structural and chemical analysis of the ferritization products revealed the formation of ferromagnetic crystalline phases, including lepidocrocite (ɣ-FeOOH), ferrooxygite (δ-FeOOH), and magnetite (Fe₃O₄). Increasing the aeration rate and use of ultrasound treatment enhances Fe₃O₄ content and iron ion removal efficiency. The adsorption capacity of the recycled materials for Zn²⁺ removal was assessed under different pH conditions using mechanical mixing and ultrasound treatment. The highest level of Zn²⁺ removal (92.0%) was achieved at pH 8 with ultrasound-activated sorbents containing 61.3% δ-FeOOH and 38.7% Fe₃O₄. At pH 10, magnetite-based sorbents achieved over 98.9% Zn²⁺ removal, enabling the treated water’s reuse in industrial rinsing processes. Electron microscopy and X-ray fluorescence confirmed the presence of fine, spherical magnetite and zinc ferrite particles. These findings underscore the potential of ferritization-based recycling as an eco-friendly and efficient strategy for heavy metal removal from galvanic wastewater. Full article

(1→3)-α-d-Glucan is an important component of the cell wall of most fungi. The polymer has many applications, including as a therapeutic agent in the prevention or treatment of various diseases, as well as a heavy metal sorbent and a component of new materials used in the plastics industry. The presence of (1→3)-α-d-glucan (water-insoluble, alkali-soluble polysaccharide) in the cell wall of Pleurotus djamor (pink oyster mushroom) was confirmed using specific fluorophore-labeled antibodies. Therefore, the water-insoluble fraction (WI-ASF) of P. djamor B123 fruiting bodies was isolated by alkaline extraction and used for further analyses. The structural features of the WI-ASF were determined by composition analysis, linkage analysis, Fourier transform infrared and Raman spectroscopy, ¹H and ¹³C nuclear magnetic resonance spectroscopy, scanning electron microscopy, as well as viscosity, specific rotation, and gel permeation chromatography. These studies revealed the presence of glucose units linked by α-glycosidic bonds and scanty amounts of mannose and xylose. Furthermore, methylation analysis of WI-ASF demonstrated that the (1→3)-linked glucopyranose (Glcp) is the primary moiety (86.4%) of the polymer, while the 3,4- and 3,6-substituted hexoses are the branching residues of the glucan. The results of chemical and spectroscopic investigations indicated that the analyzed WI-ASF is a (1→3)-linked α-d-glucan type with a molecular weight of 552 kDa. Full article

The widespread use of gadolinium (Gd) in medical and industrial applications, especially as a contrast agent in magnetic resonance imaging (MRI), has led to its increasing presence in surface waters, disrupting natural geochemical cycles and posing risks to aquatic ecosystems. Addressing this challenge, recent studies have explored the potential of magnetic materials, such as spinel ferrite nanoparticles, in the removal of Gd from contaminated water sources. The present study specifically focused on the use of MnFe₂O₄ nanoparticles to remove Gd from contaminated solutions, employing response surface methodology (RSM) to optimize sorption conditions. Key variables evaluated included salinity (0–30 g/L), initial Gd concentration (1–5 μmol/L), and sorbent dose (20–180 mg/L), at a fixed pH of 6. The results revealed that salinity had a minimal impact on Gd sorption, likely due to the high sorbent mass used. Optimal conditions were identified as a sorbent dose of 165 mg/L, an initial Gd concentration of 1.3 μmol/L, and a salinity level of 13.4 g/L, at pH 6. The process was efficient and rapid, achieving over 90% Gd removal within 1 h in both freshwater and saline conditions, and over 75% removal in mineral water within 3 h. The high efficiency and celerity of this method suggest that MnFe₂O₄ nanoparticles are a promising solution for treating Gd-contaminated hospital effluents. Future research should focus on validating these results in real-world effluent matrices and addressing the environmental and economic aspects of large-scale implementation, thereby contributing to sustainable water remediation strategies. Full article

Rice husk (RH), a globally abundant agri-food waste, presents a promising renewable silicon source for producing SBA-15 mesoporous silica-based materials. This study aimed to synthesize and bifunctionalize SBA-15 using RH as a silica precursor, incorporating sulfonic and octadecyl groups to create a mixed-mode sorbent, RH-SBA-15-SO₃H-C18, with reversed-phase and cation exchange properties. The material’s structure and properties were characterized using advanced techniques, including X-ray diffraction, infrared spectroscopy, N₂ adsorption–desorption isotherms, nuclear magnetic resonance, and electron microscopy. These analyses confirmed an ordered mesoporous structure with a high specific surface area of 238 m²/g, pore volume of 0.45 cm³/g, pore diameter of 32 Å, and uniform pore distribution, highlighting its exceptional textural qualities. This sorbent was effectively utilized in solid-phase extraction to purify 29 alkaloids from three families—tropane, pyrrolizidine, and opium—followed by an analysis using ultra-high performance liquid chromatography coupled to ion-trap tandem mass spectrometry. The developed analytical method was validated and applied to gluten-free bread samples, revealing tropane and opium alkaloids, some at concentrations exceeding regulatory limits. These findings demonstrate that RH-derived RH-SBA-15-SO₃H-C18 is a viable, efficient alternative to commercial sorbents for monitoring natural toxins in food, offering a sustainable solution for repurposing agri-food waste while addressing food safety challenges. Full article

In this study, a method for the determination of eight biogenic amines (BAs), including tyramine (Tyr), 2-phenylethylamine (2-Phe), histamine (His), tryptamine (Trp), spermidine (Spd), spermine (Spm), cadaverine (Cad), and putrescine (Put), in crab was established using ultra-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS), using a magnetic solid-phase extraction (MSPE) pretreatment, without derivatization, and the content changes in regard to these eight biogenic amines in the traditional Chinese dish, pickled swimming crabs, were investigated. The samples were purified via MSPE, using C nanofiber-coated magnetic nanoparticles (Fe₃O₄@C-NFs) as sorbents. The experimental variables involved in the MSPE, including the solution pH, adsorption and desorption time, adsorbent usage, and type and volume of the eluent, were investigated and optimized. Method validation indicated that the developed method showed good linearity (R² > 0.995); the average recovery rates were 84.7% to 115%, with the intra-day and inter-day relative standard deviations (RSD, n = 6) ranging from 3.7% to 7.5% and 4.2% to 7.7%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the eight BAs were 0.1 mg/kg~1.0 mg/kg and 0.3 mg/kg~3.0 mg/kg, respectively. Finally, this method was applied to determine the changes in the eight biogenic amines in pickled swimming crabs (Portunus trituberculatus) during storage at 20 °C and 400 BAC. Among the BAs evaluated, Cad, Put, and Tyr were the predominant amines formed during storage. The final content of Cad, Put, and Tyr reached 22.9, 20.1, and 29.0 mg/100 g at 4 °C for 16 d, and 47.1, 52.3, and 72.0 mg/100 g at 20 °C for 96 h, respectively. The results from this study can be used to expand the application range of magnetic materials in biogenic amine pretreatment and to strengthen the quality control of the traditional Chinese dish, pickled swimming crabs. Full article

In this work, mesoporous silicas with two types of mesoporous structures were synthesized and functionalized with sulfonic acid groups: MCM-41-SO₃H (honeycomb-like hexagonal structure) and MSU-2-SO₃H (three-dimensional porous structure with wormhole pores). The synthesized materials were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption–desorption, Fourier-transform infrared spectroscopy, ²⁹Si solid-state nuclear magnetic resonance spectroscopy, and elemental analysis. The obtained functionalized materials were evaluated as sorbents for strong cation-exchange solid-phase extraction (SPE) to determine their efficiency in the adsorption and desorption of tropane alkaloids (atropine and scopolamine). The loading solvents, loading volume, analyte concentration, and elution volume were studied, using 50 mg of both materials. Analyses were carried out by ultra-high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry. The synthesized MCM-41-SO₃H material presented the highest recovery efficiency and has proven to be a promising sorbent for strong cation-exchange SPE of atropine and scopolamine in aqueous media. The high degree of functionalization of MCM-41-SO₃H and the high accessibility of the sulfonic groups for the target analytes, due to the regularity and uniformity of their pores, maximize the contact between the alkaloids and the sorbent, favoring efficient adsorption. Full article

In this work, we revisited the method of effervescence-assisted microextraction, aiming to assess the effects of the process of effervescence on the extraction efficiency of organic compounds. We used a magnetic nano-sorbent material composed of stearic acid-coated cobalt-ferrite magnetic nanoparticles as an adsorbent and dispersed it in water using 12 combinations of acid and base mixtures at two different mass ratios. The solution pH, the ionic strength, and the duration of effervescence were calculated and correlated to the extraction efficiency of nonpolar UV filters from aqueous samples as model organic compounds. Our findings provide a general perspective into the influence of the process of effervescence on extraction efficiency. Based on these findings, we developed and optimized a new analytical method for extracting UV filters from water samples using HPLC-UV as a detector. Under the optimum experimental conditions (0.2 g fumaric acid/0.1 g Na₂CO₃, 50 mg of magnetic nanoparticles and methanol as an elution solvent assisted by vortex agitation for 5 min) the method was found to afford good linearity in the calibration curves expanding by two orders of magnitude, satisfactory reproducibility and repeatability (1.8–11.1%), and high recoveries (78.4–127.1%). This research provides a new perspective on the influence of the process of effervescence on the extraction efficiency of nonpolar organic compounds and introduces a new method for extracting UV filters from aqueous media. Full article

The escalating demand for lithium has intensified the need to process critical lithium ores into battery-grade materials efficiently. This review paper overviews the transformation processes and cost of converting critical lithium ores, primarily spodumene and brine, into high-purity battery-grade precursors. We systematically examine the study findings on various approaches for lithium recovery from spodumene and brine. Dense media separation (DMS) and froth flotation are the most often used processes for spodumene beneficiation. Magnetic separation (MS) and ore gravity concentration techniques in spodumene processing have also been considered. To produce battery-grade lithium salts, the beneficiated-concentrated spodumene must be treated further, with or without heat, in the presence of acidic or alkaline media. As a result, various pyro and hydrometallurgical techniques have been explored. Moreover, the process of extracting lithium from brine through precipitation, liquid–liquid extraction, and polymer inclusion membrane separation employing different organic, inorganic, and composite polymer sorbents has also been reviewed. Full article

The advancement of traditional sample preparation techniques has brought about miniaturization systems designed to scale down conventional methods and advocate for environmentally friendly analytical approaches. Although often referred to as green analytical strategies, the effectiveness of these methods is intricately linked to the properties of the sorbent utilized. Moreover, to fully embrace implementing these methods, it is crucial to innovate and develop new sorbent or solid phases that enhance the adaptability of miniaturized techniques across various matrices and analytes. Graphene-based materials exhibit remarkable versatility and modification potential, making them ideal sorbents for miniaturized strategies due to their high surface area and functional groups. Their notable adsorption capability and alignment with green synthesis approaches, such as bio-based graphene materials, enable the use of less sorbent and the creation of biodegradable materials, enhancing their eco-friendly aspects towards green analytical practices. Therefore, this study provides an overview of different types of hybrid graphene-based materials as well as their applications in crucial miniaturized techniques, focusing on offline methodologies such as stir bar sorptive extraction (SBSE), microextraction by packed sorbent (MEPS), pipette-tip solid-phase extraction (PT-SPE), disposable pipette extraction (DPX), dispersive micro-solid-phase extraction (d-µ-SPE), and magnetic solid-phase extraction (MSPE). Full article

A review of the application of matrix solid-phase dispersion (MSPD) in the extraction of biologically active compounds and impurities from plants and food samples with a particular emphasis on conventional and new types of sorbents has been provided. An overview of MSPD applications for the isolation of organic residues from biological samples, determined using chromatographic and spectroscopic techniques, has been presented. In this study, procedural solutions that may extend MSDP applicability for the extraction such as vortex-assisted, ultrasound-assisted, microwave-assisted, and extraction with a magnetic sorbent have been discussed. Special attention has been paid to MSPD sorbents including modified silica, diatomite, magnesium silicate, alumina, carbon materials (carbon nanotubes, graphene oxide, graphene, or graphite), molecularly imprinted polymers, and cyclodextrin. An important aspect of the MSPD procedure is the use of high-purity and environmentally friendly solvents for extraction (e.g., deep eutectic solvents), with such criteria being the most important for modern analytical chemistry. Many advantages of MSPD are presented, such as high recoveries, the requirement for a smaller volume of solvent, and shorter procedure times than classical methods. Full article

In the past few decades, considerable scientific strides have been made in the subject of drug analysis in human biological samples. However, the risk caused by incorrect drug plasma levels in patients still remains an important concern. This review paper attempts to investigate the advances made over the last ten years in common sample preparation techniques (SPT) for biological samples based on solid sorbents, including solid-phase extraction (SPE) and solid-phase micro-extraction (SPME), and in particular in the field of molecularly imprinted polymers (MIPs), including non-stimuli-responsive and stimuli-responsive adsorbents. This class of materials is known as ‘smart adsorbents’, exhibiting tailored responses to various stimuli such as magnetic fields, pH, temperature, and light. Details are provided on how these advanced SPT are changing the landscape of modern drug analysis in their coupling with liquid chromatography-mass spectrometry (LC-MS) analytical techniques, a general term that includes high-performance liquid chromatography (HPLC) and ultra-high performance liquid chromatography (UHPLC), as well as any variation of MS, such as tandem (MS/MS), multiple-stage (MSⁿ), and high-resolution (HRMS) mass spectrometry. Some notes are also provided on coupling with less-performing techniques, such as high-performance liquid chromatography with ultraviolet (HPLC-UV) and diode array detection (HPLC-DAD) detection. Finally, we provide a general review of the difficulties and benefits of the proposed approaches and the future prospects of this research area. Full article

The aim of this study is to solve the problems of the complicated pretreatment and high analytical cost in the detection technology of trace drugs and their metabolites in municipal wastewater. A high-performance magnetic sorbent was fsynthesized for the enrichment of trace drugs and their metabolites in wastewater to develop a magnetic solid-phase extraction pretreatment combined with the acoustic ejection mass spectrometry (AEMS) analytical method. The magnetic nanospheres were successfully prepared by magnetic nanoparticles modified with divinylbenzene and vinylpyrrolidone. The results showed that the linear dynamic range of 17 drugs was 1–500 ng/mL, the recovery was 44–100%, the matrix effect was more than 51%, the quantification limit was 1–2 ng/mL, and the MS measurement was fast. It can be seen that the developed magnetic solid-phase extraction (MSPE) method is a good solution to the problems of the complicated pretreatment and analytical cost in the analysis of drugs in wastewater. The developed magnetic material and acoustic excitation pretreatment coupled with mass spectrometry analysis method can realize the low-cost, efficient enrichment, and fast analysis of different kinds of drug molecules in urban sewage. Full article

A magnetic polymer material based on natural polymers—humic acids and magnetite, pre-configured for the sorption of a metal ion—was obtained. The magnetic polymer material was obtained via the interaction of a natural polymer, magnetite nanoparticles and sorbed metal ions that were used as a template. Moreover, the formation of a pre-polymerization complex was followed by copolycondensation with an amine in the presence of a crosslinking agent and further removal of metal ions from the crosslinked copolymer. The physicochemical properties of the resulting materials were determined using various physical methods. The composition of the resulting magnetic polymer materials was characterized by elemental analysis using an Elementar Unicube elemental analyzer. It was found that the carbon content increases by 8.28% and nitrogen by 0.42% for the polymer material Fe₃O₄:HA:T:AA; for the polymer material Fe₃O₄:HA:AA, the carbon content increases by 14.61% and nitrogen by 3.01%. Based on the IR spectra data, it is clear that magnetic polymer materials have much in common before hydrolysis (Fe₃O₄:HA:T:AA) and after hydrolysis (Fe₃O₄:HA:AA). The structure of the resulting polymer materials was studied using electron microscopy. Micrographs show the presence of pores in magnetic polymer materials after acid hydrolysis, indicating the formation of imprints. The results of the study of the sorption properties of magnetic polymer materials showed that after acid hydrolysis, the sorption capacity of a customized magnetic polymer material increases two times and it can act as a magnetic sorption material. Full article

The study aimed to prepare a biocomposite containing Yarrowia lipolytica yeast cells with magnetic properties. The work proposes the use of this biocomposite as a sorbent for the removal of organic pollutants like methylene blue from liquids. The sorption process was conducted in a periodic process through which different parameters were analyzed such as initial concentration (50–250 mg/dm³), time of the process (0.167–24 h), and temperature (25–40 °C). To fit the experimental data to theoretical models, the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models were used. In addition, pseudo-first-rate, pseudo-second-rate order, Weber–Morris and Elovich kinetic models were evaluated. The highest fit was the Freundlich isotherm model (R² = 0.9959 and ARE = 3.41%) and the pseudo-second-rate order model (R² = 0.9989 and ARE = 1.14%). It has been shown that the process of removing methylene blue using a biocomposite is exothermic and its usefulness decreases with an increase in temperature (from 32.10 mg/g to 23.64 mg/g). To acquire information about the material characteristics, different instrumental methods were applied: FTIR, SEM-EDX, TGA, and VSM. This study provides new information on the possibility of using composites made of biochar, yeast, and magnetic particles in the process of removing dyes from an aqueous environment. The obtained biocomposite is effective in removing contaminants and is easily separated after the performed process. Full article