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Extensive use of α-pinene in cosmetics, and medicine, especially for its antioxidant/antibacterial, and anti-cancer properties, and also as a flavoring agent, has made it a versatile product. α-Pinene (one of the two pinene isomers) is the most abundant terpene in nature. When extracting α-pinene from plants and, to a lesser extent, fruits, given that its purity is essential, purification methods should also be used as described in this study. Also, an attempt has been made to describe the extraction techniques of α-pinene, carried out by conventional and novel methods. Some disadvantages of conventional methods (such as hydrodistillation or solvent extraction) are being time consuming, low capacity per batch and being labor intensive and the requirement of trained operators. Most novel methods, such as supercritical fluid extraction and microwave-assisted extraction, can reduce the extraction time, cost, and energy compared to conventional methods, and, in fact, the extraction and preservation efficiency of α-pinene in these methods is higher than conventional methods. Although the above-mentioned extraction methods are effective, they still require rather long extraction times. In fact, advanced methods such as green and solvent-free ultrasonic-microwave-assisted extraction are much more efficient than microwave-assisted extraction and ultrasound-assisted extraction because the extraction efficiency and separation of α-pinene in these methods are higher; furthermore, no solvent consumption and maximum extraction efficiency are some crucial advantages of these techniques. However, the application of some novel methods, such as ultrasound-assisted extraction, in industry scale is still problematic because of their intricate design data.
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Electrochemically co-deposited sol-gel/Cu nanocomposites have been introduced as a novel, simple and single-step technique for preparation of solid-phase microextraction (SPME) coating to extract methadone (MDN) (a synthetic opioid) in urine samples. The porous surface structure of the sol-gel/Cu nanocomposite coating was revealed by scanning electron microscopy. Direct immersion SPME followed by HPLC-UV determination was employed. The factors influencing the SPME procedure, such as the salt content, desorption solvent type, pH and equilibration time, were optimized. The best conditions were obtained with no salt content, acetonitrile as desorption solvent type, pH 9 and 10 min equilibration time. The calibration graphs for urine samples showed good linearity. The detection limit was about 0.2 ng mL-1 . Also, the novel method for preparation of nanocomposite fiber was compared with previously reported techniques for MDN determination. The results show that the novel nanocomposite fiber has relatively high extraction efficiency.
Assuntos
Cobre/química , Metadona/urina , Nanocompostos/química , Entorpecentes/urina , Dióxido de Silício/química , Microextração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão/métodos , Galvanoplastia , Humanos , Limite de Detecção , Nanocompostos/ultraestrutura , Transição de FaseRESUMO
A method based on dispersive liquid-liquid microextraction (DLLME) was developed for the quantitative extraction of Ochratoxin A (OTA) from raisin samples. The influence of various parameters on the recovery of OTA such as type and volume of DLLME extractant, centrifuging and sonication time, also volume of deionized water was investigated. Recovery values under the optimum conditions were between 68.6 and 85.2 %, the inner and intra-day precision expressed as relative standard deviation (RSD%, n = 3), were less than 15 % at spiking levels of 2.5-30 µg kg(-1). Linearity was studied from 0.5 to 30 µg L(-1), and the limits of detection (LOD) and quantification (LOQ) were 0.7 and 2.0 µg kg(-1), respectively. Real samples were analyzed by DLLME method and compared with confirmative immunoaffinity Column Chromatography (IAC) clean-up. Low cost, simplicity of operation, speed and minimum consumption of organic solvent were the main advantages of proposed method. The mean contamination of samples was 0.88 µg kg(-1) that was lower than European Legal Limit.
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An efficient adsorbent was synthesized and used in magnetic dispersive solid phase extraction (MDSPE) of aflatoxins B1, B2, G1, and G2 at trace levels in pistachio prior to analysis by HPLC equipped with a fluorescence detector. Spirulina (Sp) algae was first magnetized, followed by surface modification with dopamine (Dp). The adsorbent was characterized using FT-IR, XRD, FE-SEM, EDX, VSM, and BET analyses. The effects of different analytical parameters on the extraction performance were evaluated. Under optimal conditions, good limits of detection (LODs) and quantifications (LOQs) were achieved in the ranges of 0.02-0.07 and 0.06-0.21 ng g-1, respectively. The RSDs were 5.9, 6.3, 5.6, and 7.3% for AFB1, G1, B2, and G2, respectively. The proposed method was successfully used to determine AFs in pistachio samples and acceptable recoveries in the range of 72-95% were obtained.
Assuntos
Aflatoxinas , Nanocompostos , Pistacia , Spirulina , Aflatoxinas/análise , Cromatografia Líquida de Alta Pressão , Indóis , Limite de Detecção , Polímeros , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Agricultural commodities, particularly cereals can be contaminated with mycotoxins during the pre- and post-harvest stage. The main goal of this study was to evaluate the efficacy of magnetic zeolite nanocomposite (MZNC) as an adsorbent for the reduction of mycotoxins in barley flour. The MZNC is synthesised using an eco-friendly and efficient procedure and characterised by zeta potential, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The adsorbent amount that affects the adsorption capacity was optimised. Low amounts of the nanocomposite removed >99% of aflatoxins, 50% of ochratoxin A, 22% of zearalenone, and 1.8% of the deoxynivalenol from the contaminated sample and adsorption by MZNC was better than the natural zeolite; this phenomenon is related to the wide surface of nanocomposites. Results provide new insights into possible future research that could overcome the challenges of using nanotechnology to eliminate mycotoxins from agricultural products. It can be hoped that the presence of cheap and eco-friendly mycotoxin binders such as the MZNC that is synthesised and utilised in this research will help to produce secure food and feed products.
Assuntos
Aflatoxinas/química , Hordeum/efeitos dos fármacos , Micotoxinas/química , Nanotecnologia/métodos , Ocratoxinas/química , Tricotecenos/química , Zearalenona/química , Adsorção , Centaurea , Grão Comestível/química , Fenômenos Magnéticos , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Pós , ZeolitasRESUMO
The application of Pd/Fe3O4 nanoparticles (NPs) for the adsorption of sulfathiazole (STZ) from urine samples prior to high performance liquid chromatography-ultraviolet detection was studied. Pd/Fe3O4 NPs were synthesized using plant extract. Possible impact parameters in the extraction process such as magnetic adsorbents amount, extraction time, sample pH, and desorption conditions were investigated and optimized. Under the optimum conditions, the detection and quantification limits were 10 and 30 ng mL-1, respectively. The relative standard deviation for five measurements of 100 ng mL-1 of STZ was 5.8 %. The proposed method was used for the analysis of different urine samples, and acceptable recoveries in the range of 87.6 - 101.3% were obtained. These results indicated that biosynthesized Pd/Fe3O4 NPs can be used as an efï¬cient adsorbent for extraction of sulfathiazole from urine samples.
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OBJECTIVE: Palladium nanoparticles (Pd NPs) supported on the TiO2 NPs were prepared using Euphorbia thymifolia L. leaf extract. The Pd/TiO2 NPs were characterized by FESEM, EDS, TEM and XRD analysis and were used as nanocatalysts for the reduction of a variety of organic dyes. To the best of the author's knowledge, this study explains the first report to the synthesis of Pd/TiO2 NPs using Euphorbia thymifolia L. leaf extract. METHOD: 1.0 G of TiO2 was dispersed in 40 mL of 0.3 Mm PdCl2 solution and sonicated for 30 min. Then, 20 mL of the plant extract was mixed under continuous stirring at 60°C for 2 h. The prepared Pd/TiO2 NPs were centrifuged, washed and then dried. RESULTS: FESEM imaging showed the formation of NPs in the size range of 19-29 nm. The Pd/TiO2 NPs exhibited high activity towards the reduction of Methyl Orange, Congo red and Rhodamine B in the presence of NaBH4 in aqueous medium during 4, 1 and 54 s, respectively. CONCLUSION: The synthesis of the Pd/TiO2 NPs by this route is rapid, simple, less time consuming, environmentally safe and compatibility for medical and pharmaceutical applications because of minimizing the use of toxic or hazardous organic solvents and reagents. Furthermore, the biosyenthesized nanocatalyst can catalyze the reduction of organic dyes during short-time and can be recovered and recycled several times without significant loss of activity.
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Compostos Azo/química , Vermelho Congo/química , Nanopartículas/química , Extratos Vegetais/química , Rodaminas/química , Euphorbia/química , Oxirredução , Óxidos/química , Paládio/química , Tamanho da Partícula , Folhas de Planta/química , Propriedades de Superfície , Titânio/química , Água/químicaRESUMO
In current research, Ag/RGO/Fe3O4 nanocomposite was synthesized through applying the aqueous extract of Lotus garcinii leaves through a two-step method. The plant extract was utilized as agents for reduction and stabilization in biosynthesizing nanocomposite. The green synthesized nanocatalyst was characterized by FT-IR, FE-SEM, EDX, XRD, TEM, UV-Vis absorption spectroscopy. The catalytic activity of the biosynthesized nanocomposite was studied by reducing different colored solutions contained organic pollutants such as 4-nitrophenol (4-NP), Congo red (CR) and Rhodamine B (RhB). In order to verify commercial applications of the prepared heterogeneous nanocatalyst, reusability and recoverability tests were performed in five successive catalytic reactions.
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Corantes/química , Óxido Ferroso-Férrico/química , Grafite/química , Lotus/química , Nitrofenóis/química , Extratos Vegetais/metabolismo , Prata/química , Catálise , Óxido Ferroso-Férrico/metabolismo , Grafite/metabolismo , Lotus/metabolismo , Oxirredução , Extratos Vegetais/químicaRESUMO
This study demonstrates a clean, non-toxic and environment friendly synthetic strategy for the preparation of the Natrolite zeolite/Cu nanoparticles (NPs) using Natrolite zeolite as a natural support and Anthemis xylopoda flowers aqueous extract as a reducing and stabilising agent for the synthesis of Cu NPs. Cu NPs with 20â nm diameter were immobilised homogeneously on the surface of Natrolite zeolite. The synthesised Natrolite zeolite/Cu NPs was used as an environmentally benign catalyst for the reduction of 4-nitrophenol, congo red and methylene blue in aqueous media at an ambient temperature. It has been found that the catalyst can be reused several times without any decrease in activity.
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Vermelho Congo/química , Cobre/química , Química Verde , Nanopartículas Metálicas/química , Azul de Metileno/química , Nitrofenóis/química , Silicatos/química , Zeolitas/química , Anthemis/química , Catálise , Flores/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxirredução , Extratos Vegetais/química , Espectrometria por Raios X , TermogravimetriaRESUMO
In this paper, we report the green synthesis of the Cu/Fe3O4 nanoparticles using Silybum marianum L. seeds extract and their application as magnetically separable nanocatalyst for the reduction of nitroarenes. Our method is clean, nontoxic and environment friendly. The synthesized nanocatalyst is characterized by XRD, TEM, EDS and UV-visible techniques. UV-visible spectroscopy is used to monitor the kinetics of the Cu/Fe3O4 nanoparticles formation. The results from Fourier transform infrared spectroscopy showed that the C=O and C-O groups in the plant seeds extract played a critical role in capping the nanoparticles. The expected reaction mechanism in the formation of nanoparticles is also reported. The catalyst is recoverable by magnetic decantation and could be reused several times without significant loss in catalytic activity.
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Cobre/química , Nanopartículas de Magnetita/química , Nitrocompostos/síntese química , Extratos Vegetais/química , Sementes/química , Silybum marianum/química , Catálise , Fenômenos Magnéticos , Estrutura Molecular , Nitrocompostos/química , Oxirredução , Extratos Vegetais/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Água/químicaRESUMO
A facile, efficient and environmentally-friendly protocol has been developed for the green synthesis of CuO nanoparticles (NPs) by aqueous extract of Gundelia tournefortii as a mild, renewable and non-toxic reducing agent. CuO NPs were characterized by SEM, TEM, XRD, EDS, FT-IR and UV-vis spectroscopy. More importantly, the green synthesized CuO NPs presented excellent catalytic activity for reduction of 4-nitrophenol and synthesis of N-monosubstituted ureas via hydration of cyanamides with the aid of acetaldoxime as an effective water surrogate in ethanol as a green solvent. The catalyst was easily separated and the recovered catalyst was reused many times without any significant loss of the catalytic activity.
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Asteraceae/química , Cobre/química , Química Verde , Nanopartículas/química , Nitrofenóis/química , Ureia/síntese química , Catálise , Cianamida/química , Reutilização de Equipamento , Nanopartículas/ultraestrutura , Oxirredução , Oximas/química , Extratos Vegetais/química , Ureia/análogos & derivadosRESUMO
During this study, we report the green synthesis of silver nanoparticles (Ag NPs) using Euphorbia helioscopia Linn leaf extract for the synthesis of propargylamines. Also, the structural and optical properties are studied. The synthesized nanoparticles are characterized by TEM, XRD, FT-IR and UV-visible techniques. UV-visible studies show an absorption band at 440 nm due to surface plasmon resonance (SPR) of the silver nanoparticles. Furthermore, the catalyst exhibits high catalytic activity, superior cycling stability and excellent substrate applicability.
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Euphorbia/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Folhas de Planta/química , Prata/químicaRESUMO
Novel dispersive liquid-liquid microextraction (DLLME), coupled with high performance liquid chromatography with photodiode array detection (HPLC-DAD) has been applied for the extraction and determination of cyproheptadine (CPH), an antihistamine, in human urine samples. In this method, 0.6 mL of acetonitrile (disperser solvent) containing 30 µL of carbon tetrachloride (extraction solvent) was rapidly injected by a syringe into 5 mL urine sample. After centrifugation, the sedimented phase containing enriched analyte was dissolved in acetonitrile and an aliquot of this solution injected into the HPLC system for analysis. Development of DLLME procedure includes optimization of some important parameters such as kind and volume of extraction and disperser solvent, pH and salt addition. The proposed method has good linearity in the range of 0.02-4.5 µg mL(-1) and low detection limit (13.1 ng mL(-1)). The repeatability of the method, expressed as relative standard deviation was 4.9% (n = 3). This method has also been applied to the analysis of real urine samples with satisfactory relative recoveries in the range of 91.6-101.0%.
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A simple and environmentally friendly microextraction technique was used for determination of chlorpheniramine (CPM), an antihistamine drug, in human urine samples using dispersive liquid-liquid microextraction (DLLME) followed by high performance liquid chromatography with diode array detection (HPLC-DAD). In this extraction technique, an appropriate mixture of acetonitrile (disperser solvent) and carbon tetrachloride (extraction solvent) was rapidly injected into the urine sample containing the target analyte. Tiny droplets of extractant were formed and dispersed into the sample solution and then sedimented at the bottom of the conical test tube by centrifugation. Under optimal conditions, the calibration curve was linear in the range of 0.055-5.5 µg mL-1, with a detection limit of 16.5 ng mL-1. This proposed method was successfully applied to the analysis of real urine samples. Low consumption of toxic organic solvents, simplicity of operation, low cost and acceptable figures of merit are the main advantages of the proposed technique.
Utilizou-se uma técnica de microextração simples e ambientalmente amigável para a determinação de clorfeniramina (CPM), anti-histamínico, em amostras de urina humana, utilizando a microextração dispersiva líquido-líquido (DLLME), seguida por cromatografia líquida de alta eficiência com detecção por arranjo de diodos (HPLC-DAD). Nesse método de extração, mistura apropriada de acetonitrila (solvente dispersor) e tetracloreto de carbono (solvente de extração) foi injetada rapidamente na amostra de urina contendo o analito alvo. As pequenas gotículas de agente de extração foram formadas e dispersas na solução da amostra e, em seguida, sedimentadas no fundo do tubo cônico de ensaio por centrifugação. Em condições ótimas, a curva de calibração foi linear no intervalo entre 0,055 e 5,5 µg mL-1, com limite de detecção de 16,5 ng mL-1. O método proposto foi aplicado com sucesso na análise de amostras de urina reais. Baixo consumo de solventes orgânicos tóxicos, simplicidade de operação, baixo custo e figuras de mérito aceitáveis são as principais vantagens do método sugerido.