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•Environmental concerns have fortified scientists to produce novel composites.•This review presents the commonly used processing techniques of natural fibers.•Provide a robust data ...base for further development of polymer composites materials.•Create a novel sustainable composite material dedicated for industrial applications.
Designing environmentally friendly materials from natural resources represents a great challenge in the last decade. However, the lack of fundamental knowledge in the processing of the raw materials to fabricate the composites structure is still a major challenge for potential applications.
Natural fibers extracted from plants are receiving more attention from researchers, scientists and academics due to their use in polymer composites and also their environmentally friendly nature and sustainability. The natural fiber features depend on the preparation and processing of the fibers. Natural plant fibers are extracted either by mechanical retting, dew retting and/or water retting processes. The natural fibers characteristics could be improved by suitable chemicals and surface treatments. This survey proposes a detailed review of the different types of retting processes, chemical and surface treatments and characterization techniques for natural fibers. We summarize major findings from the literature and the treatment effects on the properties of the natural fibers are being highlighted.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Muddy tidal flats with landforms vary widely over space and time. The evolution of tidal flats topography has had a significant impact on the region. Therefore, there is a need to develop methods for ...rapidly and accurately characterizing tidal flats topography. This study applied thresholding segmentation (TS), machine learning, and two image classification methods to Sentinel-2 remote sensing images to extract the instantaneous waterline of the northern part of the North Jiangsu Radial sand Ridges (NJRSR). Tidal level data at specific time intervals were obtained using the Delft3D and TPXO9 models, after which tidal flats topography inversion was conducted. As a result, varied among the different classification methods, with the K-Nearest Neighbors (KNN) algorithm producing the optimal waterline extraction. Furthermore, the accuracy of tidal level simulation was improved by employing Delft3D software and constructing a scaled-down model of the study area. Comparisons with Delft3D model simulations of tidal levels with observations at three tide gauge stations yielded accuracies of 17.5 cm, 18.5 cm and 17.9 cm, this result showed that the establishment of the tidal level model can enhance the accuracy of tidal flats Digital Elevation Model (DEM) inversion. In fact, the combined application of the KNN algorithm and Delft3D model within retrieval of tidal level provided the most accurate topographic inversion, with an average error of 0.297 m, which was reduced to 0.292 m after median filtering, and the results indicated a trend of southward erosion in the tidal flats in the study area, with a turning point roughly located in the southern part of Doulong Port. The results of this study can help improve the future monitoring of dynamic changes in intertidal wetland topography and the conservation and development of tidal flats areas.
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•The K-Nearest Neighbors (KNN) algorithm producing the optimal waterline extraction.•Constructing a small model of the study area improve the tidal level data accuracy.•Verified the accuracy of the algorithm in the process of topographic evolution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Plastic film mulching has been extensively used in farmland, especially in arid regions, for over half-century. However, this has led to heavy pollution of soils by microplastics (MPs). Currently, ...efficient extraction of MPs from the organo-mineral soil matrix is a problem because microsize clay particles tightly adhere to MPs. It is therefore extremely challenging to investigate, identify, quantify, and characterize MP particles and their behavior in agricultural soils. In this study, we developed a simple and effective method of separating and extracting MPs from the soil matrix. Clean polyethylene (PE) MPs were obtained after a series of treatments including pressure leaching, flotation, electrostatic adsorption, and concentrated sulfuric acid (98% H2SO4) carbonization. The characteristics of MP pollutants, such as abundance, size, and morphology, in soils that have been continuously mulched with PE film for various periods of time were determined after extraction. The highest abundance of MPs (40.35 mg/kg) with sizes ranging from 0.9–2.0 mm was found in soil samples that had been continuously mulched with plastic film for 30 years. The sampled MP particles are in the microplastic size (0.8–0.3 mm) range, and the size of MPs decreases gradually as the period of mulching increased. Scanning electron microscopy analysis showed that the surface of the MP particles showed visible cracks, with round holes, and the particle surface roughened as the number of years of continuous mulching increased. Fourier-transform infrared spectroscopy results showed that the absorption peak area of hydrocarbyl (–CH2) of PE MPs decreased significantly, and the typical oxidation characteristic peak area increased as the mulching period increased. The concentration of mesoplastics also increased, from 91.20 mg/kg to 308.50 mg/kg, when the mulching period increased from 5 to 30 years.
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•A simple and effective method of extraction of microplastics from the soil matrix in an arid region was established.•The size of the microplastics decreased and the abundance increased gradually as the period of film mulching increased.•The surface morphology of the microplastics became rougher as the duration of continuous film mulching increased.•The typical oxidation characteristic absorption peak area increased as the soil residence of PE microplastics increased.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•The content of bioactive compounds of the oils was affected by the species, method and its interaction.•The oil extracted from C. moschata with MP showed high values of fucosterol and ...stigmasterol.•The oil extracted from C. argyrosperma with MP presented a higher content of chlorophyll b and total carotenoids.•The highest content of squalene was reported for C. moschata oil by MP.•δ─tocopherol was the most predominant in the pumpkin oils.
In this study, the effect of the extraction method (mechanical pressing, MP and organic solvent, OS) and the specie (Cucurbita argyrosperma Huber, CA; and Cucurbita moschata Duchesne, CM) on the content of bioactive compounds and antioxidant activity of oil from pumpkin of Yucatan, Mexico was investigated. Between the two extraction methods, the oil extracted by MP obtained the highest values for total phenolic compounds (TPC), total carotenoids, squalene, quercetin, β-carotene, fucosterol, stigmasterol and antioxidant activity (DPPH, ABTS and reducing power). Between the two species, the CM oil extracted with MP or OS exhibited the highest values for carotenoids, sterols and antioxidant activity (DPPH and ABTS). Thus, it can be concluded that the method and specie affect the composition of bioactive compounds and antioxidant activity of the pumpkin oil. This information is useful for the extraction of pumpkin oil with a higher content of compounds, of interest for the industry.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Unmodified hairy basil seed mucilage (Ocimum basilicum L.), with attractive features as structural functionality and adsorption capacity, was employed as a green biosorbent for dispersive solid phase ...extraction and enrichment of oxytetracycline, tetracycline, and doxycycline before quantitation by HPLC-UV for the first time. Hairy basil crushed seed increased the contacting surface area and was completely dispersed in the sample solution to extract tetracyclines under acidic condition with the assistance of ultrasonic waves. The analytes in the extraction phase were separated on a C18 column under isocratic condition with a mobile phase consisted of acetonitrile and trifluoroacetic acid. Influence of chemical and physical variables on the extraction efficiency of the developed method was investigated and optimized systematically. Under the optimal condition of all experimental parameters, good linear ranges were obtained at 15.0–500 μg L−1 for tetracyclines with determination coefficients more than 0.9994. Limits of detection (LODs) and limits of quantitation (LOQs) ranged 5.0–7.0 and 15.0 μg L−1, respectively. Relative standard deviations (RSDs) of the proposed method at 100 and 300 μg L−1 for TCs were less than 13 % and 10 %, respectively with percentage TC recoveries from spiked standard ranging 83.1–109.9 %. This simple, reliable, cost-effective, and environmentally friendly method was successfully applied for the analysis of tetracycline residues in milk. The greenness of the proposed method was assessed using the Analytical Eco-Scale and AGREE protocol.
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•Unmodified HBSM was used as a green biosorbent for DSPE for the first time.•Alternative DSPE based on biosorbent was utilized to enrich TC residues in milk.•UAE was synergized with DSPE to enhance extraction efficiency.•After preconcentration using the developed method TCs were quantified by HPLC-UV.•This method is simple, reliable, cost-effective, and environmentally friendly.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•State of the art in LC-MS-based lipidomics.•Sample extraction, separation, ionization and detection in LC-MS-based lipidomics.•Data processing, lipid identification/quantification, quality control ...in lipidomics.•Highlights of recent lipidomics studies.
Liquid chromatography-mass spectrometry (LC-MS)-based lipidomics has undergone dramatic developments over the past decade. This review focuses on state of the art in LC-MS-based lipidomics, covering all the steps of global lipidomic profiling.
By reviewing 185 original papers and application notes, we can conclude that current advanced LC-MS-based lipidomics methods involve:
(1)lipid extraction schemes using chloroform/MeOH or methyl tert-butyl ether (MTBE)/MeOH, both with addition of internal standards covering each lipid class;(2)LC separation of lipids using short microbore C18 or C8 columns with sub-2-µm or 2.6–2.8-µm (fused-core) particle size with analysis time <30 min;(3)electrospray ionization in positive- and negative-ion modes with full spectra acquisition using high-resolution MS with capability to MS/MS.
Phospholipids (phosphatidylcholines, phosphatidylethanolamines, phosphatidylinositols, phosphatidylserines, phosphatidylglycerols) followed by sphingomyelins, di- and tri-acylglycerols, and ceramides were the most frequently targeted lipid species.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Plastic pollution is one of the major challenges in the Anthropocene. A plastic waste sub-product, microplastics (<5 mm), has been regarded as contaminants of concern for its detrimental effects and ...widespread in the environment. Most studies assessing microplastics focused on marine environments, while terrestrial and soil systems have been overlooked. In this review, we analyzed the current knowledge regarding microplastic pollution in natural soil or agricultural ecosystems. We focused on reviewing the procedural steps for microplastic extraction and identification in detail. The heterogeneity of the methods applied, lack of standardized procedures and incompatible parameters reported, make the results incomparable among most studies. Several microplastic concentration units are needed to make studies comparable. Correctly determining and reporting microplastic morphotypes are key to understanding the sources of contamination. Minimal considerations and recommendations were stated for extraction, digestion, filtration, and polymer identification procedures. Baseline contamination prevention measures were identified as mandatory along the entire sampling, handling and identification procedures. Lastly, knowledge gaps were identified and discussed for further research.
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•MPs abundance in soil depend on the source, site characteristic and methods used.•Reporting the MP types and chemical classification is mandatory.•Heterogeneity of methods used in literature make results incomparable.•Novel methods need to overcome important frontiers and challenges.•Minimal standards along the extraction and identification procedure are suggested.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
► Bioactive compounds of plant materials. ► Necessity of proper extraction methods for extracting bioactive compounds from plants for further processing. ► Extraction of bioactive compounds by ...conventional extraction methods. ► Use of non-conventional extraction techniques as green techniques for bioactive compounds extraction.
The use of bioactive compounds in different commercial sectors such as pharmaceutical, food and chemical industries signifies the need of the most appropriate and standard method to extract these active components from plant materials. Along with conventional methods, numerous new methods have been established but till now no single method is regarded as standard for extracting bioactive compounds from plants. The efficiencies of conventional and non-conventional extraction methods mostly depend on the critical input parameters; understanding the nature of plant matrix; chemistry of bioactive compounds and scientific expertise. This review is aimed to discuss different extraction techniques along with their basic mechanism for extracting bioactive compounds from medicinal plants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Microplastics (MPs) contamination is an existing and concerning environmental issue. Plastic particles have been observed worldwide in every natural matrix, with water environments being the final ...sink of dispersed MPs. Microplastic distribution in water ecosystems varies as a function of multiple factors, including polymer properties (e.g., density and wettability) and environmental conditions (e.g., water currents and temperature). Because of the tendency of MPs to settle, sediment is known to be one of the most impacted environmental matrices. Despite the increasing awareness of their diffusion in sediments, a proper quantification of dispersed particles is still difficult, due to the lack of standard protocols, which avoid a proper comparison of different sites. This hampers the current knowledge on environmental implications and toxicological effects of MPs in sediments. In this work, we examined 49 studies carried out from 2004 to 2020 to describe the different extraction methods applied, and to highlight pros and cons, with the aim of evaluating the more promising protocols. Therefore, we evaluated each proposed method by considering precision, reproducibility, economic viability and greenness (in term of used reagents). Finally, we proposed a valid alternative procedure in term of reliability and costs, which can attract increasing interest for future studies.
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•Microplastics (MPs) contamination is an environmental issue.•Plastic particles have been observed almost worldwide in every natural environments.•A proper quantification of dispersed particles in sediments is still difficult.•Different extraction methods of MPs from sediments are described.•A valid alternative in term of reliability and costs for the extraction is proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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