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1.
J Breath Res ; 18(4)2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39089291

RESUMEN

Polymeric bags are a widely applied, simple, and cost-effective method for the storage and offline analysis of gaseous samples. Various materials have been used as sampling bags, all known to contain impurities and differing in their cost, durability, and storage capabilities. Herein, we present a comparative study of several well-known bag materials, Tedlar (PVF), Kynar (PVDF), Teflon (PTFE), and Nalophan (PET), as well as a new material, ethylene vinyl copolymer (EVOH), commonly used for storing food. We investigated the influences of storage conditions, humidity, bag cleaning, and light exposure on volatile organic compound concentration (acetone, acetic acid, isoprene, benzene, limonene, among others) in samples of exhaled human breath stored in bags for up to 48 h. Specifically, we show high losses of short-chain fatty acids (SCFAs) in bags of all materials (for most SCFAs, less than 50% after 8 h of storage). We found that samples in Tedlar, Nalophan, and EVOH bags undergo changes in composition when exposed to UV radiation over a period of 48 h. We report high initial impurity levels in all the bags and their doubling after a period of 48 h. We compare secondary electrospray ionization and proton transfer reaction mass spectrometry in the context of offline analysis after storage in sampling bags. We provide an analytical perspective on the temporal evolution of bag contents by presenting the intensity changes of all significantm/zfeatures. We also present a simple, automated, and cost-effective offline sample introduction system, which enables controlled delivery of collected gaseous samples from polymeric bags into the mass spectrometer. Overall, our findings suggest that sampling bags exhibit high levels of impurities, are sensitive to several environmental factors (e.g. light exposure), and provide low recoveries for some classes of compounds, e.g. SCFAs.


Asunto(s)
Pruebas Respiratorias , Polímeros , Humanos , Pruebas Respiratorias/instrumentación , Pruebas Respiratorias/métodos , Polímeros/análisis , Compuestos Orgánicos Volátiles/análisis , Espiración , Manejo de Especímenes/métodos , Manejo de Especímenes/instrumentación
2.
Int J Mol Sci ; 25(13)2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-39000186

RESUMEN

Microplastics (MPs) pervade the environment, infiltrating food sources and human bodies, raising concerns about their impact on human health. This review is focused on three key questions: (i) What type of polymers are humans most exposed to? (ii) What are the prevalent shapes of MPs found in food and human samples? (iii) Are the data influenced by the detection limit on the size of particles? Through a systematic literature analysis, we have explored data on polymer types and shapes found in food and human samples. The data provide evidence that polyester is the most commonly detected polymer in humans, followed by polyamide, polyurethane, polypropylene, and polyacrylate. Fibres emerge as the predominant shape across all categories, suggesting potential environmental contamination from the textile industry. Studies in humans and drinking water reported data on small particles, in contrast to larger size MPs detected in environmental research, in particular seafood. Discrepancies in size detection methodologies across different reports were identified, which could impact some of the discussed trends. This study highlights the need for more comprehensive research on the interactions between MPs and biological systems and the effects of MPs on toxicity, together with standardised analytical methodologies to accurately assess contamination levels and human exposure. Understanding these dynamics is essential for formulating effective strategies to mitigate the environmental and health implications of MP pollution.


Asunto(s)
Agua Potable , Microplásticos , Microplásticos/análisis , Humanos , Agua Potable/análisis , Agua Potable/química , Contaminantes Químicos del Agua/análisis , Polímeros/química , Polímeros/análisis , Monitoreo del Ambiente/métodos , Contaminación de Alimentos/análisis
3.
Chemosphere ; 361: 142520, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38834092

RESUMEN

Organic fertilizers have become a vector for the transport of microplastics (MPs), which pose human health concerns through the food chain. This study aimed to quantify and characterize MPs in eight different compost samples of various raw materials and their subsequent translocation to lettuce (Lacuta sativa) grown on contaminated composts. The results revealed that the MP abundance ranged from 3810 to 16530 MP/kg. Municipal solid waste compost (MSWC) had highest abundance (16082 ± 632 MP/kg), followed by leaf compost (LC) and organic compost (OC) (6299 ± 1011 and 3680 ± 419 MP/kg, respectively). MPs of <100 µm in size were most dominant in MSWC and LC. Fragments and fibers were the prevalent shape types, with white/transparent colored MPs being more abundant. Polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) were the dominant polymers. MPs accumulation in the lettuce leaves was greatest in the lettuce plants grown on MSWC, followed by those grown on LC and OC, indicating that MSWC grown lettuce is not suitable for human consumption. The decrease in the growth (leaf length, number of leaves, leaf fresh and weights) and physiological (membrane stability index, relative water contents) parameters of lettuce was in line with the trend of MP accumulations. Hence, it is highly important to regulate the plastic contents in compost because it is a threat to ecosystems and human health.


Asunto(s)
Compostaje , Lactuca , Microplásticos , Contaminantes del Suelo , Microplásticos/análisis , Lactuca/metabolismo , Lactuca/crecimiento & desarrollo , Lactuca/química , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo , Suelo/química , Hojas de la Planta/metabolismo , Hojas de la Planta/química , Monitoreo del Ambiente , Polímeros/análisis , Residuos Sólidos/análisis , Polietileno , Fertilizantes/análisis , Polipropilenos
4.
Mar Pollut Bull ; 205: 116594, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38875967

RESUMEN

Plastic litter affects coastal and marine ecosystems globally. This study represents the first record of pyroplastics and plasticrust in the beaches of Tamil Nadu, India. All samples were FTIR spectroscopically examined to confirm the polymer composition of the suspected plastics. The 16 plastic formations were found in TamilNadu, including six plastiglomerates nine pyroplastics and one plasticrust. Five types of polymers (PET, PP, PVC, PA, and PE) were found on the plastic matrices. The study also revealed that pyroplastics and plasticrust formed by degradation of plastics through weathering in the coastal environment. The present study also found that four types of marine fouling organisms such as oyster larvae, bryozoan, barnacle and polychaete worm were encrusted on the two pyroplastics. The emergence of these new forms of plastic raises concerns about their interactions with the environment and biota.


Asunto(s)
Monitoreo del Ambiente , Plásticos , India , Plásticos/análisis , Animales , Contaminantes Químicos del Agua/análisis , Poliquetos , Organismos Acuáticos , Polímeros/análisis
5.
Sci Total Environ ; 932: 173031, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38723961

RESUMEN

The widespread extensive use of synthetic polymers has led to a substantial environmental crisis caused by plastic pollution, with microplastics detected in various environments and posing risks to both human health and ecosystems. The possibility of plastic fragments to be dispersed in the air as particles and inhaled by humans may cause damage to the respiratory and other body systems. Therefore, there is a particular need to study microplastics as air pollutants. In this study, we tested a combination of analytical pyrolysis, gas chromatography-mass spectrometry, and gas and liquid chromatography-mass spectrometry to identify and quantify both microplastics and their additives in airborne particulate matter and settled dust within a workplace environment: a WEEE treatment plant. Using this combined approach, we were able to accurately quantify ten synthetic polymers and eight classes of polymer additives. The identified additives include phthalates, adipates, citrates, sebacates, trimellitates, benzoates, organophosphates, and newly developed brominated flame retardants.


Asunto(s)
Contaminantes Atmosféricos , Monitoreo del Ambiente , Microplásticos , Material Particulado , Plásticos , Polímeros , Microplásticos/análisis , Polímeros/análisis , Monitoreo del Ambiente/métodos , Material Particulado/análisis , Contaminantes Atmosféricos/análisis , Plásticos/análisis , Cromatografía de Gases y Espectrometría de Masas , Humanos , Retardadores de Llama/análisis , Polvo/análisis
6.
Chemosphere ; 356: 141946, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38604518

RESUMEN

End-of-life electric and electronic devices stand as one of the fastest growing wastes in the world and, therefore, a rapidly escalating global concern. A relevant fraction of these wastes corresponds to polymeric materials containing a plethora of chemical additives. Some of those additives fall within the category of hazardous organic compounds (HOCs). Despite the significant advances in the capabilities of analytical methods, the comprehensive characterization of WEEE plastic remains as a challenge. This research strives to identify the primary additives within WEEE polymers by implementing a non-target and suspect screening approach. Gas chromatography coupled to time-of-flight mass spectrometry (GC-QTOF-MS), using electron ionization (EI), was applied for the detection and identification of more than 300 substances in this matrix. A preliminary comparison was carried out with nominal resolution EI-MS spectra contained in the NIST17 library. BPA, flame retardants, UV-filters, PAHs, and preservatives were among the compounds detected. Fifty-one out of 300 compounds were confirmed by comparison with authentic standards. The study establishes a comprehensive database containing m/z ratios and accurate mass spectra of characteristic compounds, encompassing HOCs. Semi-quantification of the predominant additives was conducted across 48 WEEE samples collected from handling and dismantling facilities in Galicia. ABS plastic demonstrated the highest median concentrations, ranging from 0.154 to 4456 µg g-1, being brominated flame retardants and UV filters, the families presenting the highest concentrations. Internet router devices revealed the highest concentrations, containing a myriad of HOCs, such as tetrabromobisphenol A (TBBPA), tribromophenol (TBrP), triphenylphosphate (TPhP), tinuvin P and bisphenol A (BPA), most of which are restricted in Europe.


Asunto(s)
Residuos Electrónicos , Cromatografía de Gases y Espectrometría de Masas , Plásticos , Residuos Electrónicos/análisis , Plásticos/análisis , Plásticos/química , Retardadores de Llama/análisis , Sustancias Peligrosas/análisis , Compuestos Orgánicos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Fenoles/análisis , Compuestos de Bencidrilo/análisis , Monitoreo del Ambiente/métodos , Polímeros/química , Polímeros/análisis
7.
Plant Foods Hum Nutr ; 79(2): 545-550, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38642193

RESUMEN

Gluten-free foods (GF) availability on supermarket shelves is growing and it is expected to continue expanding in the years ahead. These foods have been linked to a lower content of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), molecules that trigger gastrointestinal symptoms in sensitive persons. In this study, the FODMAP content of 25 cereal-based GF foods in Spain (breakfast cereals, pasta, bread, biscuits, bakery products, and dough and puff pastry) and 25 gluten-containing equivalents (GC) available in the same supermarket were analysed and compared. Lactose, fructose, glucose, sorbitol, mannitol, raffinose, stachyose and fructans were quantified. In a like-by-like analysis, GF foods were found to generally contain fewer FODMAPs than their GC counterparts. The ingredients used in the manufacture of GF cereal-based foods may contribute to this fact. When the individually wrapped size was considered, the proportion of samples classified as high-FODMAPs in GC and GF foods showed a trend towards fewer samples in the GF. However, not all the GF samples were low-FODMAP. Altogether, our findings provide essential information for FODMAP content databases of GF products in Spain.


Asunto(s)
Dieta Sin Gluten , Disacáridos , Grano Comestible , Glútenes , Monosacáridos , Oligosacáridos , Polímeros , Grano Comestible/química , España , Monosacáridos/análisis , Glútenes/análisis , Oligosacáridos/análisis , Disacáridos/análisis , Polímeros/análisis , Fermentación , Fructanos/análisis , Lactosa/análisis , Pan/análisis , Humanos , Rafinosa/análisis , Fructosa/análisis
8.
J Vis Exp ; (205)2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38526125

RESUMEN

Single-use laboratory plastics exacerbate the pollution crisis and contribute to consumable costs. In extracellular vesicle (EV) isolation, polycarbonate ultracentrifuge (UC) tubes are used to endure the associated high centrifugal forces. EV proteomics is an advancing field and validated re-use protocols for these tubes are lacking. Re-using consumables for low-yield protein isolation protocols and downstream proteomics requires reagent compatibility with mass spectroscopy acquisitions, such as the absence of centrifuge tube-derived synthetic polymer contamination, and sufficient removal of residual proteins. This protocol describes and validates a method for cleaning polycarbonate UC tubes for re-use in EV proteomics experiments. The cleaning process involves immediate submersion of UC tubes in H2O to prevent protein drying, washing in 0.1% sodium dodecyl sulfate (SDS) detergent, rinsing in hot tap water, demineralized water, and 70% ethanol. To validate the UC tube re-use protocol for downstream EV proteomics, used tubes were obtained following an experiment isolating EVs from cardiovascular tissue using differential UC and density gradient separation. Tubes were cleaned and the experimental process was repeated without EV samples comparing blank never-used UC tubes to cleaned UC tubes. The pseudo-EV pellets obtained from the isolation procedures were lysed and prepared for liquid chromatography-tandem mass spectrometry using a commercial protein sample preparation kit with modifications for low-abundance protein samples. Following cleaning, the number of identified proteins was reduced by 98% in the pseudo-pellet versus the previous EV isolation sample from the same tube. Comparing a cleaned tube against a blank tube, both samples contained a very small number of proteins (≤20) with 86% similarity. The absence of polymer peaks in the chromatograms of the cleaned tubes was confirmed. Ultimately, the validation of a UC tube cleaning protocol suitable for the enrichment of EVs will reduce the waste produced by EV laboratories and lower the experimental costs.


Asunto(s)
Vesículas Extracelulares , Cemento de Policarboxilato , Proteómica , Proteómica/métodos , Vesículas Extracelulares/metabolismo , Proteínas/metabolismo , Polímeros/análisis , Agua/metabolismo
9.
Food Chem ; 447: 138952, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-38461720

RESUMEN

The edible coating is proved to be a convenient approach for fruit preservation. Among these published explorations, naturally sourced macromolecules and green crosslinking strategies gain attention. This work centers on edible coatings containing Ca2+ as crosslinker for the first time, delving into crosslinking mechanisms, include alginate, chitosan, Aloe vera gel, gums, etc. Additionally, the crucial functions of Ca2+ in fruit's quality control are also elaborated in-depth, involving cell wall, calmodulin, antioxidant, etc. Through a comprehensive review, it becomes evident that Ca2+ plays a dual role in fruit edible coating. Specifically, Ca2+ constructs a three-dimensional dense network structure with polymers through ionic bonding. Moreover, Ca2+ acts directly with cell wall to maintain fruit firmness and serve as a second messenger to participate secondary physiological metabolism. In brief, coatings containing Ca2+ present remarkable effects in preserving fruit and this work may provide guidance for Ca2+ related fruit preservation coatings.


Asunto(s)
Películas Comestibles , Conservación de Alimentos , Conservación de Alimentos/métodos , Calcio/análisis , Polímeros/análisis , Frutas/química
10.
Food Chem ; 446: 138890, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38452510

RESUMEN

Today, the wide use of triazole fungicides due to environmental damage and its side effects has raised global concern. Hence, in this research, poly-vinyl alcohol/polyacrylic-acid/CoFe-PBA@GO electrospun nanofiber was synthesized and applied as effective, degradable, and novel adsorbent at pipette-tip microextraction (PT-µSPE) method for the rapid and concurrent extraction of five of triazole fungicides in fruit and vegetable samples prior to quantitative analysis by high-performance liquid chromatography-ultraviolet. The incorporation of CoFe-PBA@GO with superporous structure and abundant functional groups in a polymer medium improves the extraction efficiency of nanofibers due to hydrogen bonding and π-π interactions formed between analytes and synthesized nano-adsorbent. Various important elements that affect the extraction yield of the target analytes were optimized utilizing a time-variable approach. Under the optimum conditions, dynamic range was attained in the range of 0.3-900.0 ng/mL with correlation coefficients ≥ 0.999. The identification limit of the PT-µSPE-HPLC-UV method ranged from 0.1 to 0.3 ng/mL.


Asunto(s)
Fungicidas Industriales , Nanofibras , Cromatografía Líquida de Alta Presión , Nanofibras/química , Triazoles/análisis , Fungicidas Industriales/análisis , Polímeros/análisis , Extracción en Fase Sólida/métodos , Límite de Detección
11.
Food Chem ; 445: 138698, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38350198

RESUMEN

Developing effective methods for highly sensitive detection of phenolic endocrine disruptors (EDCs) is especially urgent. Herein, a magnetic hydroxyl-functional porous organic polymer (M-FH-POP) was facilely synthesized by green diazo-couple reaction using basic fuchsin and hesperetin as monomer for the first time. M-FH-POP delivered superior adsorption performance for phenolic EDCs. The adsorption mechanism was hydrogen bonds, hydrophobic interaction and π-π interplay. With M-FH-POP as adsorbent, a magnetic solid phase extraction method was established for extracting trace phenolic EDCs (bisphenol A, 4-tert-butylphenol, bisphenol F and bisphenol B) in water and fish before ultra-high performance liquid chromatography tandem mass spectrometry analysis. The method displayed low detection limit (S/N = 3) of 0.05-0.15 ng mL-1 for water and 0.08-0.3 ng g-1 for fish. The spiked recoveries were 88.3 %-109.8 % with the relative standard deviations of 2.4 %-6.4 %. The method offers a new strategy for sensitive determination of phenolic EDCs in water and fish samples.


Asunto(s)
Disruptores Endocrinos , Agua , Animales , Agua/análisis , Disruptores Endocrinos/análisis , Polímeros/análisis , Porosidad , Cromatografía Líquida de Alta Presión/métodos , Extracción en Fase Sólida/métodos , Fenómenos Magnéticos , Límite de Detección
12.
Biomater Sci ; 12(5): 1079-1114, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38240177

RESUMEN

Hydrogels, formed from crosslinked hydrophilic macromolecules, provide a three-dimensional microenvironment that mimics the extracellular matrix. They served as scaffold materials in regenerative medicine with an ever-growing demand. However, hydrogels composed of only organic components may not fully meet the performance and functionalization requirements for various tissue defects. Composite hydrogels, containing inorganic components, have attracted tremendous attention due to their unique compositions and properties. Rigid inorganic particles, rods, fibers, etc., can form organic-inorganic composite hydrogels through physical interaction and chemical bonding with polymer chains, which can not only adjust strength and modulus, but also act as carriers of bioactive components, enhancing the properties and biological functions of the composite hydrogels. Notably, incorporating environmental or stimulus-responsive inorganic particles imparts smartness to hydrogels, hence providing a flexible diagnostic platform for in vitro cell culture and in vivo tissue regeneration. In this review, we discuss and compare a set of materials currently used for developing organic-inorganic composite hydrogels, including the modification strategies for organic and inorganic components and their unique contributions to regenerative medicine. Specific emphasis is placed on the interactions between the organic or inorganic components and the biological functions introduced by the inorganic components. The advantages of these composite hydrogels indicate their potential to offer adaptable and intelligent therapeutic solutions for diverse tissue repair demands within the realm of regenerative medicine.


Asunto(s)
Hidrogeles , Medicina Regenerativa , Medicina Regenerativa/métodos , Hidrogeles/química , Matriz Extracelular/química , Sustancias Macromoleculares , Polímeros/análisis , Ingeniería de Tejidos/métodos
13.
Talanta ; 270: 125582, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38176248

RESUMEN

Despite substantial developments in minimally invasive lactate monitoring microneedle electrodes, most such electrode developments have focused on either sensitivity or invasiveness while ignoring a wide range of detection, which is the most important factor in measuring the normal range of lactate in interstitial fluid (ISF). Herein, we present a polymer-based planar microneedle electrode fabrication using microelectromechanical and femtosecond laser technology for the continuous monitoring of lactate in ISF. The microneedle is functionalized with two-dimensional reduced graphene oxide (rGO) and electrochemically synthesized platinum nanoparticles (PtNPs). A particular quantity of Nafion (1.25 wt%) is applied on top of the lactate enzyme to create a diffusion-controlled membrane. Due to the combined effects of the planar structure of the microneedle, rGO, and membrane, the biosensor exhibited excellent linearity up to 10 mM lactate with a limit of detection of 2.04 µM, high sensitivity of 43.96 µA mM-1cm-2, a reaction time of 8 s and outstanding stability, selectivity, and repeatability. The feasibility of the microneedle is evaluated by using it to measure lactate concentrations in artificial ISF and human serum. The results demonstrate that the microneedle described here has great potential for use in real-time lactate monitoring for use in sports medicine and treatment.


Asunto(s)
Técnicas Biosensibles , Grafito , Nanopartículas del Metal , Humanos , Ácido Láctico/análisis , Polímeros/análisis , Nanopartículas del Metal/química , Líquido Extracelular/química , Platino (Metal)/química , Técnicas Biosensibles/métodos , Electrodos
14.
J Sep Sci ; 47(2): e2300802, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38286730

RESUMEN

Polyethylene glycol (PEG) is one of the most commonly used polymers in drug delivery systems. The investigation of the pharmacokinetic behavior of PEG is important for revealing the toxicity and efficiency of PEG-related Nano-drug delivery systems. A high through-put and selective ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method coupled with collision-induced dissociation (CID) in source technique was developed and validated to determine PEG1K polymers in cellular samples in this study. The countless precursor ions of PEG1K are dissociated in the source to generate numerous product ions which have different numbers of subunits. The transition of [M+H]+ precursor ions → product ions at m/z 177.1 (four subunits)→89.1 (two subunits) was selected to determine PEG1K due to its high sensitivity. The UHPLC-MS/MS method coupled with CID in the source showed good linearity over the range of 0.1-10 µg/mL. Intra-day and inter-day accuracies and precisions of the assay were all within ± 12.39%. The assay was successfully applied to a cellular pharmacokinetic study of PEG1K in human breast cancer cells. The cytotoxicity of PEG1K polymers was also studied and the results indicated that the cytotoxicity of PEG1K was not significant in the range of 5-1200 µg/mL.


Asunto(s)
Polímeros , Espectrometría de Masas en Tándem , Humanos , Espectrometría de Masas en Tándem/métodos , Cromatografía Líquida de Alta Presión/métodos , Polímeros/toxicidad , Polímeros/análisis , Polietilenglicoles/química , Iones
15.
Mar Pollut Bull ; 200: 116051, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38271918

RESUMEN

Plastic pollution is widespread in oceans and the ingestion of plastic by marine organisms is causing concern about potential adverse effects. The purpose of this study was to analyze the different types of plastics in the digestive tract of female small-spotted catshark (Scyliorhinus canicula). An alkaline digestion method using 10 % potassium hydroxide (KOH), was used. The samples were filtered and visually observed to classify the plastics according to size, shape, and color. Raman spectroscopy was further employed to identify the polymer types. The study found the presence of plastics in 89.5 % of the 200 females analyzed, including 10 polymers, with polystyrene (PS), polyamide-6 (PA6), polyvinyl chloride (PVC), and silicone rubber (SR) being the most common. The polymers identified largely reflect the results of similar studies in the marine environment and were similar to global polymer diversity of microplastics, which highlights the potential of S. canicula females for biomonitoring microplastic pollution.


Asunto(s)
Elasmobranquios , Contaminantes Químicos del Agua , Animales , Femenino , Microplásticos/análisis , Plásticos/análisis , Monitoreo Biológico , Prevalencia , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Tracto Gastrointestinal/química , Polímeros/análisis
16.
J Pharm Biomed Anal ; 240: 115947, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38181557

RESUMEN

Huangqi Liuyi Decoction, a famous classical Chinese prescription, shows significant curative effect on diabetes and its complications, in which calycosin-7-glucoside, liquiritin and glycyrrhizic acid are the main components that playing these mentioned pharmacological activity, under the synergistic action of various other ingredients in the decoction. However, there are significant differences in the content of active compounds in Chinese medicinal materials, which mainly due to origin, picking seasons, and processing methods. Hence, the accurate content of the glycosides is the prerequisite for ensuring the pharmacological efficacy. Aiming at establishing an efficient extraction and determination method for accurate quantitative analysis of calycosin-7-glucoside, liquiritin and glycyrrhizic acid in Huangqi Liuyi Decoction, an on line solid-phase extraction-high-performance liquid chromatography method was developed, using a homemade bio-based monolithic adsorbent. The bio-based adsorbent was prepared in a stainless steel tube, using bio-monomers of methyleugenol and S-allyl-L-cysteine, which effectively reduced the dependence of the polymer field on non-renewable fossil resources and reduced carbon emissions. Furthermore, the prepared adsorbent owned abundant chemical groups, which can produce interactions of hydrogen bond, dipole-dipole, π-π and hydrophobic force with the target glycosides, thus improving the specific recognition ability of the adsorbent. The experiments were carried out on an LC-3000 HPLC instrument with a six-way valve. Methodology validation indicates that the recovery is in the range of 97.0%-103.4% with the RSD in the range of 1.6%-4.0%, due to the specific selectivity of the bio-based monolithic adsorbent for these three glycosides, and good matrix-removal ability for Huangqi Liuyi decoction. The limit of detection is 0.17, 0.50 and 0.33 µg/mL for calycosin-7-glucoside, liquiritin and glycyrrhizic acid, respectively, and the limit of quantitation is 0.50, 1.50 and 1.00 µg/mL, respectively, with the linear range of 2-200 µg/mL for calycosin-7-glucoside, and 5-500 µg/mL for liquiritin and glycyrrhizic acid. The present work provided a simple and efficient method for the extraction and determination of glycosides in complex medicinal plants.


Asunto(s)
Astragalus propinquus , Medicamentos Herbarios Chinos , Glicósidos , Polímeros/análisis , Ácido Glicirrínico , Medicamentos Herbarios Chinos/química , Glucósidos/análisis , Cromatografía Líquida de Alta Presión/métodos
17.
Int J Biol Macromol ; 259(Pt 2): 129270, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38199531

RESUMEN

A deep understanding of the inherent roles of wood polymers such as cellulose, hemicelluloses, and lignin in the hierarchical structure of wood is of key importance for advancing functional wood-based materials but is currently lacking. To address this gap, we clarified the underexplored contributions of wood polymer assemblies to the structural support and compressive properties of wood by chemically removing polysaccharides or lignin from wood blocks of a conifer Cryptomeria japonica. Compositional and structural evaluations revealed that cellulose, hemicelluloses, and lignin contributed to the dimensional stability of wood, especially that the polysaccharide network at cell corners sustained the honeycomb cell structure. Wood polymer assemblies featuring the anatomical structure of wood were also evaluated in terms of compressive properties. The modulus and strength reflected the density and anisotropy, whereas fracture behavior was well characterized by each wood polymer assembly through the classification of stress-strain curves based on principal component analysis. The difference in fracture behaviors indicated that the rigid lignin and flexible cellulose assemblies, possibly mediated by hemicelluloses, complementarily determine the unique compressive response of wood. These findings enable the adjustment of wood functionality and the selection of composite components for wood modification while inspiring the development of novel wood applications.


Asunto(s)
Lignina , Madera , Lignina/química , Madera/química , Polímeros/análisis , Polisacáridos/química , Celulosa/química
18.
Int J Biol Macromol ; 259(Pt 2): 129273, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38211922

RESUMEN

In this paper, lignocellulosic fibers and cellulose microfibrils (CMFs) were extracted from palmyra fruit peduncle waste and investigated as naturally derived cellulosic materials for their potential use as reinforcement materials in composite applications. The physicochemical, mechanical, and thermal properties of the extracted fiber were studied. Physical and morphological analysis results revealed an extracted fiber diameter of 82.5 µm with a very rough surface, providing excellent interfacial bonding performance with the polymer matrix. Chemical, mechanical, and thermal results showed that the fibers consist mainly of cellulose as their crystallized phase, with a cellulose content of 56.5 wt% and a tensile strength of 693.3 MPa, along with thermal stability up to 252 °C. The chemically extracted CMFs exhibit a short, rough-surfaced, cylindrical cellulose structure with a diameter range of 10-15 µm. These CMFs demonstrate excellent thermal stability, withstanding temperatures up to 330 °C. Furthermore, the formation of CMFs is evident from a substantial increase in the crystallinity index, which increased from 58.2 % in the raw fibers to 78.2 % in the CMFs. FT-IR analysis further confirms the successful removal of non-cellulosic materials through chlorine-free chemical treatments. These findings strongly support the potential use of extracted fibers and CMFs as reinforcement materials in polymers.


Asunto(s)
Frutas , Microfibrillas , Frutas/química , Espectroscopía Infrarroja por Transformada de Fourier , Celulosa/química , Polímeros/análisis
19.
Int J Biol Macromol ; 256(Pt 2): 128423, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38008138

RESUMEN

A chitin-based magnetic hyper-cross-linked polymer (labeled as Ch-MHCP) has been successfully synthesized and utilized for highly-effective solid-phase extraction of neonicotinoid insecticides (NEOs). The extraction capability of Ch-MHCP for four common NEOs is higher than that of four commercial sorbents including octadecyl-silane C18, oasis hydrophilic/lipophilic balanced sorbent, oasis mixed anion sorbent and poly-phenylacetic mixed anion sorbent. The large number of hydroxyl and amide groups as well as benzene rings in Ch-MHCP allow the H-bond and π-π* interaction to be the principal adsorption mechanism of Ch-MHCP for NEOs. Besides, polar interaction was also involved in the adsorption process. In combination of Ch-MHCP based extraction technique with high-performance liquid chromatography, a novel analytical method for sensitive detection of NEOs in lemon juice and tomatoes has been established. At optimal conditions, wide linear ranges were obtained to be 0.20-100 ng mL-1 for lemon juice and 0.80-1000 ng g-1 for tomatoes. The detection limits were 0.06-0.12 ng mL-1 for lemon juice and 0.24-0.60 ng g-1 for tomatoes. This work not only provides a powerful tool for simultaneously detecting four NEOs in lemon juice and tomatoes, but also offers a new insight into the preparation of bio-based magnetic sorbents for adsorption/removal of pollutants.


Asunto(s)
Solanum lycopersicum , Neonicotinoides , Polímeros/análisis , Quitina , Extracción en Fase Sólida/métodos , Aniones , Fenómenos Magnéticos , Cromatografía Líquida de Alta Presión/métodos
20.
Mar Pollut Bull ; 198: 115825, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38029669

RESUMEN

Transport of ballast water is considered a significant vector for dispersion of different pollutants, including microplastics (MPs), throughout the world's oceans. However, there is limited information on MPs in ballast water. Size distribution, polymer type, and ecological risks of MPs in ballast water were investigated for the first time in this study. The mean levels of MPs in ballast water and seawater samples were 12.53 and 11.80 items/L, respectively. MPs with a size category of 50-300 µm was the most abundant. Fiber, black, and polycarbonate (PC) were the predominant shape, color, and polymer type of identified MPs in ballast water and seawater, respectively. The pollution load index (PLI), hazard index (HI), and risk quotient (RQ) indicated high levels of MP pollution, potentially indicating an ecological risk. These findings increase our understanding of the major sources (such as ballast water), transportation routes, and related ecological risks of MPs to marine ecosystems.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Microplásticos/análisis , Plásticos/análisis , Agua/análisis , Ecosistema , Océano Índico , Navíos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Polímeros/análisis , Medición de Riesgo
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