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Artigos de revistas sobre o assunto "Extraction en phase solide – Purification":
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Lüdicke, Malín G., Jana Hildebrandt, Christoph Schindler, Ralph A. Sperling e Michael Maskos. "Automated Quantum Dots Purification via Solid Phase Extraction". Nanomaterials 12, n.º 12 (9 de junho de 2022): 1983. http://dx.doi.org/10.3390/nano12121983.
Resumo:
The separation of colloidal nanocrystals from their original synthesis medium is an essential process step towards their application, however, the costs on a preparative scale are still a constraint. A new combination of approaches for the purification of hydrophobic Quantum Dots is presented, resulting in an efficient scalable process in regard to time and solvent consumption, using common laboratory equipment and low-cost materials. The procedure is based on a combination of solvent-induced adhesion and solid phase extraction. The platform allows the transition from manual handling towards automation, yielding an overall purification performance similar to one conventional batch precipitation/centrifugation step, which was investigated by thermogravimetry and gas chromatography. The distinct miscibility gaps between surfactants used as nanoparticle capping agents, original and extraction medium are clarified by their phase diagrams, which confirmed the outcome of the flow chemistry process. Furthermore, the solubility behavior of the Quantum Dots is put into context with the Hansen solubility parameters framework to reasonably decide upon appropriate solvent types.
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Topçu, Aykut Arif, Süleyman Aşır e Deniz Türkmen. "DNA Purification by Solid Phase Extraction (SPE) Methods". Hacettepe Journal of Biology and Chemistry 3, n.º 44 (1 de julho de 2016): 259. http://dx.doi.org/10.15671/hjbc.20164420568.
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McCormick, Randy M. "A solid-phase extraction procedure for DNA purification". Analytical Biochemistry 181, n.º 1 (agosto de 1989): 66–74. http://dx.doi.org/10.1016/0003-2697(89)90394-1.
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Egbers, Philipp H., Tilmann Harder, Boris P. Koch e Jan Tebben. "Siderophore purification with titanium dioxide nanoparticle solid phase extraction". Analyst 145, n.º 22 (2020): 7303–11. http://dx.doi.org/10.1039/d0an00949k.
Resumo:
The study of bacterial metal chelators, so called siderophores, requires robust analytical methods that selectively target and extract strong iron-binding compounds from complex samples containing a plethora of organic molecules.
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Rolčík, Jakub, Jana Řečinská, Petr Barták, Miroslav Strnad e Els Prinsen. "Purification of 3-indolylacetic acid by solid phase extraction". Journal of Separation Science 28, n.º 12 (agosto de 2005): 1370–74. http://dx.doi.org/10.1002/jssc.200500189.
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Cruz-Villalon, Gregorio. "Synthesis of Allicin and Purification by Solid-Phase Extraction". Analytical Biochemistry 290, n.º 2 (março de 2001): 376–78. http://dx.doi.org/10.1006/abio.2001.4990.
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Cruz-Villalon, Gregorio. "Synthesis of Allicin and Purification by Solid-Phase Extraction". Analytical Biochemistry 304, n.º 2 (maio de 2002): 274. http://dx.doi.org/10.1006/abio.2002.5610.
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Xu, Sijie, Junxia Wang, Dengxian Deng, Yueying Sun, Xuedong Wang e Zhanen Zhang. "A pretreatment method combined matrix solid-phase dispersion with dispersive liquid–liquid micro-extraction for polybrominated diphenyl ethers in vegetables through quantitation of gas chromatography-tandem mass spectrometry (GC-MS)". RSC Advances 13, n.º 23 (2023): 15772–82. http://dx.doi.org/10.1039/d3ra00320e.
Resumo:
Herein, a novel pretreatment method for extraction of polybrominated diphenyl ethers (PBDEs) using matrix solid phase dispersion (MSPD) and depth purification using dispersive liquid–liquid micro-extraction (DLLME) from vegetables was designed.
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Liu, Wei, Du Shu Huang, Na Wu, Ju Cheng Zhang, Ping Yi e Jin Yang. "Determination of Organochlorine Pesticides in Saussurea Costus by Ultrasonic Extraction and Solid-Phase Microextraction Method". Advanced Materials Research 554-556 (julho de 2012): 1947–51. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.1947.
Resumo:
Ultrasonic extraction and purification using solid-phase microextraction column for the determination of 7 types of organochlorine pesticides including α, β, γ, δ-BHC, 2,4 '-DDT, 4,4'-DDT and heptachlor from the Saussrrea cotus were investigated in this study. The pretreatment of Saussrrea cotus samples, the effect of different ultrasonic time on the extraction efficiency and the effect of different ratio of dichloromethane: petroleum ether on purification efficiency were studied. Results show that the satisfactory extraction conditions for pre-treatment process are: 30 minutes ultrasonic treatment; the volume ratio of dichloromethane and petroleum ether mixture is 3:7.
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Poling, Stephen M., e Ronald D. Plattner. "Rapid Purification of Fumonisins B3and B4with Solid Phase Extraction Columns". Journal of Agricultural and Food Chemistry 44, n.º 9 (janeiro de 1996): 2792–96. http://dx.doi.org/10.1021/jf960013p.
Teses / dissertações sobre o assunto "Extraction en phase solide – Purification":
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Bartuma, Ninorta. "Optimizing purification of oligonucleotides with reversed phase trityl-on solid phase extraction". Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-76844.
Resumo:
Oligonucleotides are synthetic strings of DNA or RNA used mostly for biochemical analysis and diagnostics. For them to be useful in these fields, a purity over 90% is most often required. However, when synthesizing these sequences, many “failures” (shorter sequences) are made in the step-wise process. The synthesized oligonucleotides need to therefore be purified. This is most often done with gel electrophoresis or liquid chromatography. These methods are, on the other hand, very time-consuming and laborious. Solid phase extraction (SPE) is a much faster purification method if optimized and it can be done with the standard cartridges as well as 96-well plates, that allow many samples to efficiently be run at the same time. With reversed phase (RP) SPE, the dimethoxytrityl (DMT) group, that is attached to the target at the final synthesis step, can be used for stronger retention to the bed sorbent and leaving only the target at the final eluting stage. The impurities without a DMT-on group, that do not adsorb to the sorbent, are washed away in earlier steps. The purpose of this study is to optimize an SPE method for purification of oligonucleotides. Two different cartridges, Clarity QSP (Phenomenex) and Glen-Pak (Glen Research) were used. The purity analysis and oligonucleotide identification were done using anion exchange - high performance liquid chromatography (AIE-HPLC) and time-of-flight mass spectrometry (TOF MS). To conclude, Clarity QSP achieved, at the most, a purity of 68.8% with the recommended SPE steps by Phenomenex. Alterations in the extraction procedure resulted in similar purity or lower. Glen-Pak reached a peak purity of 78.8% when doing a double salt wash of 5% ACN in 2 M sodium chloride and another double wash after detritylation with 1% acetonitrile. This method has to be further optimized in order to reach a purity of at least 90% to be useful in industrial settings.
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Maury, Delphine. "Méthodes de purification des signaux impliqués dans la mise en place de la symbiose endomycorhizienne". Toulouse 3, 2007. http://www.theses.fr/2007TOU30241.
Resumo:
Les travaux de recherche menés s'inscrivent dans le « développement durable » du secteur agronomique. Favoriser les interactions naturelles plantes-microorganismes du sol permet de diminuer les apports excessifs d'engrais, nuisibles à l'environnement. Parmi elles, figurent les endosymbioses racinaires dont les plus répandues sont les symbioses fixatrice d'azote et mycorhizienne. Dans le cas de la symbiose fixatrice d'azote, le signal symbiotique est un facteur nod (lipochito-oligomère). Envisager une similitude dans la signalisation de ces deux symbioses, permet d'imaginer l'existence de facteurs « myc ». L'objectif de la thèse est la recherche, la purification et voire in fine, l'isolement de tels composés. Avec a priori de structure, la technique de l'empreinte moléculaire a été utilisée. Un marquage à la 2-aminobenzamide par ailleurs a été développé. Enfin, des extractions sur milieux biologiques, sans a priori de structure, ont été réalisées. Des phases polymères présentant une affinité pour les facteurs nod ont été obtenues. La purification de fractions actives contenant des composés d'origine « fongique » a ouvert des voies sur de rassurantes perspectivesEThe research tasks undertaken in this thesis lie within the scope of “durable development” and more especially in the agronomic sector. Indeed, one of the possible methods to decrease the excessive contributions of manures, often harmful with the environment, is to support the installation of the plant-microorganism natural interactions. Among them, the endosymbioses including nitrogen fixing and mycorhizal appear. The molecular dialogue between the two partners highlights the presence of a symbiotic signal in the case of the nitrogen fixing symbiosis, called nod factor, which is not other than a lipochito-oligomer. By considering a similarity in the signalising of the two symbioses, it is possible to imagine the existence of a “myc” factor with structure closed to the factor nod one. Nevertheless, the corresponding structure of “myc” factor still remains unspecified. The objective of this thesis is to seek these myc factors to even purify them and in fine, to isolate them. Work was completed according to three approaches. One the basis of an a priori of structure with the nod factor, the molecular imprinting technique was used around a lipochito-oligomer. Then a protocol of labelling with the 2-aminobenzamide was developed. Last, without an a priori of structure, a series of extractions of biological media according to a more traditional biochemical approach was carried out and the activity of the residual fractions was tested directly on the plants. The results from these various approaches made it possible to purify fractions containing compounds of “fungic” origin and to open the way to promising prospects
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Simmons, Steven Tyler. "Commercial Applicability of an Innovative Anthocyanin Purification Technique, Utilizing Mixed-Mode Solid-Phase Extraction". The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1332267706.
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Sahyoun, Wissam. "Analyse de pesticides dans les fruits et légumes : développement analytique et application de méthode QuEChERS, d-SPE et GC-MS/MS". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR082.
Resumo:
En raison de l'utilisation généralisée des pesticides, une fraction de résidus pesticides sont présents dans les fruits et légumes. La contamination des aliments par les pesticides est devenue un des problèmes sérieux. La consommation mondiale de pesticides a augmenté au cours de la dernière décennie en raison de la croissance démographique constante et de l'urbanisation rapide. Les pesticides sont très toxiques et l'exposition long terme à ces produits chimiques provoque des risques pour la santé incluant les maladies neurologiques et respiratoires.Cette étude se concentre sur l'évaluation de la concentration de 34 pesticides dans 60 légumes et fruits issus de culture conventionnelle et biologique provenance de diverses origines. Parmi ces échantillons, certains ont été étudiés sous différentes formes, avec et sans lavage, avec et sans peau. Cette dernière est pour but d'évaluer s'il y a un geste simple pour réduire la teneur de pesticides dans les fruits et légumes et réduire ainsi les impacts sanitaires de consommateur.Les travaux se focalisent premièrement sur l'optimisation de méthode d'extraction, de purification et d'analyse finale des extraits. La méthode d'extraction QuEChERS (Quick, Easy, Cheap, Rugged, Effective and Safe) et de purification d-SPE (dispersive Solide Phase Extraction) ont été utilisées. Les extraits finals ont été analyse par la chromatographie en phase gazeuse couplée à un spectromètre de masse en tandem (GC-MS/MS) pour l'identification et la quantification de chaque pesticide. L'ensemble de procédures a été optimisé et il fournit une bonne sensibilité, sélectivité, un bon rendement qui varie de 70% à 120%, et une bonne précision avec RSD <20%. L'application de la méthode sur les échantillons réels permet de déterminer la présence de pesticides dans 85 % des échantillons. Les concentrations de pesticides détectés dans les légumes et fruits ne dépassent pas les limites maximales de résidus (LMR) pour la majorité de pesticides. Cependant, quelques pesticides ont été trouvés à des niveaux supérieurs à LMR pour les fruits et légumes provenant d'Akkar au Nord de Liban. De plus parmi des pesticides détectés à des niveaux élevés figurent ceux qui ont été déjà interdis comme le cas de l'Endosulfan. Les résultats ont montré que certains gestes simples permettent de réduire les teneurs de résidus de pesticides dans les fruits et légumes. En effet, le lavage à l'eau du robinet et l'épluchage permet de réduire significativement les résidus de pesticides dans les fruits et légumes. Les fruits et légumes issus de l'agriculture biologiques présents des concentrations de pesticides plus basses que ceux issus de l'agriculture conventionnelle. De très faibles concentrations des pesticides ou dans certains cas des concentrations en dessous de limite de quantification ont été déterminés pour les fruits et légumes issus de cultures biologiquesDue to the widespread use of pesticides, a fraction of pesticide residues are present in fruits and vegetables. Pesticide contamination of food has become one of the serious problems. Global pesticide consumption has increased over the past decade due to continued population growth and rapid urbanization. Pesticides are highly toxic and long-term exposure to these chemicals causes health risks including neurological and respiratory diseases.This study focuses on the evaluation of the concentration of 34 pesticides in 60 conventionally and organically grown vegetables and fruits from various origins. Among these samples, some were studied in different forms, with and without washing, with and without skin. The purpose of the latter is to evaluate whether there is a simple gesture to reduce the content of pesticides in fruits and vegetables and thus reduce the health impacts of consumers.The work focuses firstly on the optimization of the extraction method, purification and final analysis of the extracts. The extraction method QuEChERS (Quick, Easy, Cheap, Rugged, Effective and Safe) and the purification method d-SPE (dispersive Solid Phase Extraction) were used. The final extracts were analyzed by gas chromatography coupled to a tandem mass spectrometer (GC-MS/MS) for the identification and quantification of each pesticide. The set of procedures has been optimized and it provides good sensitivity, selectivity, good yield that varies from 70% to 120%, and good precision with RSD <20%. The application of the method on real samples allows the determination of pesticides in 85% of the samples. The concentrations of pesticides detected in vegetables and fruits did not exceed the maximum residue limits (MRLs) for the majority of pesticides. However, some pesticides were found at levels above MRLs for fruits and vegetables from Akkar in Northern Lebanon. Moreover, among the pesticides detected at high levels are those that have already been banned as in the case of Endosulfan. The results showed that some simple gestures can reduce the levels of pesticide residues in fruits and vegetables. Indeed, washing with tap water and peeling significantly reduce pesticide residues in fruits and vegetables. Organically grown fruits and vegetables have lower pesticide concentrations than conventionally grown ones. Very low pesticide concentrations or in some cases concentrations below the limit of quantification were determined for organically grown fruits and vegetables
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He, Jian. "Isolation of Anthocyanin Mixtures from Fruits and Vegetables and Evaluation of Their Stability, Availability and Biotransformation in The Gastrointestinal Tract". The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1222108733.
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Leong, Yoong Kit. "Extraction and purification of green polymers using aqueous two-phase extraction (ATPE)". Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/48807/.
Resumo:
Due to the increasing concern towards depleting petroleum resource and pollutions done by conventional plastics, polyhydroxyalkanoates (PHAs) which have diverse structure variability and rapid biodegradation have gained increasing attentions as potential replacement for plastics. However, PHAs have a much higher production cost compared to that of conventional plastics due to expensive carbon source and downstream processing. Aqueous two-phase extraction (ATPE) outshines other PHAs purification techniques by having the advantages of providing a mild environment for bioseparation, being green and non-toxic, and easily scaled-up. Henceforth, this research aimed to study on the purification and recovery of PHAs using thermoseparation-based ATPE. Firstly, cloud point extraction technique which based on thermoseparating polymers (TSP)/water two phase system was employed. The recovery yield of 94.8 % and purification factor (PF) of 1.41 fold was achieved under the conditions of 20 wt/wt % ethylene oxide-propylene oxide (EOPO) with 3900 g/mol MW and 10 mM of NaCl addition at thermoseparating temperature of 60 °C. TSPs have also been coupled with ammonium sulfate to form a two-phase system. Under the condition of 14 wt/wt % of both EOPO 3900 and (NH4)2SO4 at pH 6, yield and purity up to 72 % and 60 % can be achieved. Without the need of additional TSPs top-up, recycling and reutilization of phase-forming polymers can be done at least twice with satisfying yield and PF. Using two-level full factorial design, the statistical analysis demonstrated that the phosphate and thermoseparating polymer concentration are the most significant parameters due to their individual influence and synergistic interaction between them on all response variables. Utilizing the two significant parameters, the purification and recovery of PHAs were further optimized using central composite design and achieved recovery yield as high as 99.9 %. The optimum PF of 1.431 fold was obtained at 17.12 wt/wt % of phosphate salts and 18.52 wt/wt % of EOPO 3900. Using the addition of fresh phase-forming components, a total of 4 successive purification cycles with satisfying yield and PF were demonstrated. Utilizing the carbon source screened by the preliminary integrated economic and environmental assessment developed, the feasibility of extractive bioconversion of PHAs under the influence of different parameters was studied. The strategy successfully achieved a yield and PF of 97.6 % and 1.36 fold respectively under the condition of 5 wt/wt % EOPO 3900 concentration, 30 °C fermentation temperature and pH 6. The scaling-up to 2 L bioreactor proved that the scale-up of ATPE can be predicted reliably from laboratory-scale experimental data. In the final section, the evaluation of economic and environmental performance of two processes (which are with and without thermoseparating ATPE as primary purification step) were performed. With the basis of 9,000 tons PHAs production per year and 7,920 operating hours, the process with thermoseparating ATPE as primary purification step standout in terms of both economic and environmental performance. PHA production cost of 5.77 US$/kg with a payback period of fewer than 4 years and ROI of 25.2 % was achieved. The research proved that thermoseparating ATPE is a powerful and potential technique for PHAs purification and recovery as the technique showed a much higher PHAs recovery yield (approximately 2 times) in comparison with the literature (Divyashree and Shamala, 2010). In conclusion, this opens promising standpoints for utilizing thermoseparating ATPE as the primary step in the isolation and purification of PHAs from fermented broth.
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Jajuli, Maizatul Najwa. "Extraction liquid-liquide modulée électrochimiquement et microextraction en phase solide de composés pharmaceutiques sélectionnés". Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0127.
Resumo:
Les méthodes classiques de préparation d'échantillons pour la détermination de composés polaires, telles que l'extraction liquide-liquide (LLE) et l'extraction en phase solide (SPE), ne sont généralement pas efficaces en raison de multiples étapes, d’une faible récupération et d’une consommation élevée de solvants organiques. Cette thèse traite du développement de nouvelles méthodes de préparation d’échantillons, à savoir l’extraction par voie liquide-liquide modulée électrochimiquement (EMLLE) et l’extraction bar-micro en phase solide (bar-μ-SPE) afin de déterminer les composés pharmaceutiques metformine (MET), buformine (BUF), phénformine (PHEN) et propranolol (PROP). Dans la méthode EMLLE, un champ électrique a été appliqué pour extraire les composés pharmaceutiques ionisés à travers l’interface entre deux solutions électrolytiques non miscibles (ITIES). Des ITIES se forment lorsque deux solvants en vrac en phase aqueuse (chlorure de lithium) et en phase organique (I, 2-dichloroéthane), contenant l’électrolyte, sont mis en contact. Le potentiel de transfert pour chaque analyte a été analysé par voltamétrie. Le potentiel de transfert varie avec leur lipophilie; propranolol Conventional sample preparation methods for the determination of polar compounds such as liquid-liquid extraction (LLE) and solid phase extraction (SPE) are generally not effective because of their multiple steps, low recovery and high consumption of organic solvents. Thus, this thesis deals with the development of new sample preparation methods, i.e, electrochemically modulated liquid-liquid extraction (EMLLE) and bar-micro solid phase extraction (bar-μ-SPE) to determine selected pharmaceutical compounds, i.e., metformin (MET), buformin (BUF), phenformin (PHEN), and propranolol (PROP) having varied lipophilicity in biological samples. In the EMLLE method, the aid of electric field was utilized to extract the pharmaceutical compounds across the interface between two immiscible electrolyte solutions (ITIES). ITIES formed when two bulk solvents aqueous phase (lithium chloride) and organic phase (I,2-dichloroethane), both containing electrolytes are brought into contact. Transfer potential for each analyte was analysed by voltammetry. The trend of transfer potential followed their lipophilicity; propranolol < phenformin < phenyl biguanide < metformin. Extraction of the analytes was performed by applying fixed potential to the biphasic system using potentiostat for 15 mins. The extraction performance was poor. Design of another ITIES cell and imposing interfacial potential by chemical polarization was done to enhance the extraction performance of this method. Thus, the EMLLE technique based on application of interfacial potential due to the presence of different concentrations of tetramethylammonium ion (TMA+) as common ion in each phase was studied. The optimum extraction conditions for this method are, [TMA+]o = 10 mM, [TMA+]w = 0.001 mM, Vorg = 2 mL, pHsample = 9, rotation speed = 900 rpm, extraction time = 600 s. The optimised parameters for back-extraction are: [TMA+]back = 50 mM, Vfinal = 0.1 mL, pHback = 2 . Nearly 100 % extraction of targeted analytes was achieved, and the enrichment factor obtained was up to ~ 60 for biguanide compounds. In the bar-μ -SPE method, adsorbent and a tiny metal rod was placed in a polypropylene membrane bag. Among the various adsorbents studied, graphene and zeolite showed some potential. Thus, extraction conditions were optimised for each adsorbent and adsorbent mixture. Despite the optimisations, the extraction was low (5.03-39.2 %). Nevertheless, enrichment factors of 1.49 -14.9 were obtained. Both proposed methods were applied to the determination of the analytes in urine. On the whole, the newly proposed methods are simple and markedly reduced consumption of organic solvents
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Balasubramaniam, Deepa. "Lysozyme Separation from Tobacco Extract by Aqueous Two-Phase Extraction". Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/31272.
Resumo:
Tobacco has long been considered as a host to produce large quantities of high-valued recombinant proteins. However, dealing with large quantities of biomass with a dilute concentration of product is a challenge for down-stream processing. Aqueous two-phase extraction (ATPE) has been used in purifying proteins from various sources. It is a protein-friendly process and can be scaled up easily. ATPE was studied for its applicability to recombinant protein purification from tobacco using egg white lysozyme as the model protein. Separate experiments with polyethyleneglycol(PEG)/salt/tobacco extract, and PEG/salt/lysozyme were carried out to determine the partition behavior of tobacco protein and lysozyme, respectively. Two level fractional factorial designs were used to study the effects of factors such as PEG molecular weight, PEG concentration, the concentration of phase forming salt, sodium chloride concentration, and pH on protein partitioning. The results showed that PEG/sodium sulfate system was most suitable for lysozyme purification. Detailed experiments were conducted by spiking lysozyme into the tobacco extract. The conditions with highest selectivity of lysozyme over native tobacco protein were determined using a response surface design. The purification factor was further improved by decreasing the phase ratio along the tie line corresponding to the phase compositions with the highest selectivity. Under selected conditions the lysozyme yield was predicted to be 87% with a purification factor of 4 and concentration factor of 14. The binodial curve and tie line corresponding to the optimal condition for lysozyme recovery for the PEG 3400/sodium sulfate system were developed. The selectivity at the optimal condition was experimentally determined to be 47 with a lysozyme yield of 79.6 % with a purification factor of 10 and a concentration factor of 20. From this study, ATPE was shown to be suitable for initial protein recovery and partial purification from transgenic tobacco.Master of Science
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Samatou, Joachim [Verfasser]. "Modelling and Simulation of Antibody Purification by Aqueous Two-Phase Extraction / Joachim Samatou". München : Verlag Dr. Hut, 2013. http://d-nb.info/1035049988/34.
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Holste, Angela Sarah. "Développement des méthodes bio analytique pour l’analyse quantitative et qualitative des peptides et protéines marqués par le couplage de la chromatographie et la spectrométrie de masse". Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3004/document.
Resumo:
Cette thèse est le résultat d’une cotutelle entre l'Université de Pau et des Pays de l'Adour (UPPA) à Pau, en France et l'Université Christian Albrecht (CAU) à Kiel, en Allemagne. Dans le cadre de cette collaboration internationale, des méthodes bio-analytiques sont développées pour analyser quantitativement et qualitativement des peptides et protéines marquées par le couplage de la chromatographie avec la spectrométrie de masse. Les peptides et les digestats des protéines sont marquées selon un protocole optimisé par des lanthanides en utilisant des composés à base de DOTA. La séparation des peptides est réalisée par IP-RP-nanoHPLC. Des données complémentaires sont acquises par MALDI-MS pour l'identification et par ICP-MS pour la quantification. Dans ce contexte, une étape de pré-nettoyage en ligne est développée et mise en œuvre dans le protocole de séparation par nanoHPLC. Cette étape permet l'élimination efficace des réactifs appliqués en excès et ainsi la diminution du bruit de fond lié à la présence de métaux lors des analyses par ICP-MS. Les données obtenues sont alors plus facile à interpréter, la sensibilité des signaux des peptides n’étant par ailleurs pas modifié. L'extraction en phase solide (SPE) appliquée comme alternative entraîne des pertes importantes de peptides et peut être considérée comme inadaptée pour l'analyse quantitative. Des additifs pour éluants de nanoHPLC, tels que l'EDTA et le HFBA sont testés et jugés non bénéfiques pour l'analyse des échantillons peptidiques normaux. HFBA peut être reconsidéré pour une application spéciale sur des peptides très hydrophiles. Des peptides marqués sont développés. Leur utilisation en quantité connue pourrait permettre la quantification rapide et simple d'un échantillon de digestat à faible complexité. De plus, cet ensemble de peptides permet la superposition fiable des chromatogrammes, et ainsi de comparer des données complémentaires obtenues par l’analyse d’échantillon par ICP-MS et MALDI-MS. Expériences d'application avec le couplage laser femtoseconde avec ICP-MS sont effectuées sur des plaques métalliques de MALDI MS et montrent des résultats très prometteurs. Pour cela, les échantillons préalablement identifiés par MALDI-MS sont analysés par fsLA-ICP-MS. Les premières tentatives de quantification sur la plaque en acier modifiée sont satisfaisantes et donnent des résultats répondant aux attentes. L’optimisation des paramètres de MALDI-MS facilite l’identification des peptidesThis PhD thesis was a Cotutelle between the Université de Pau et des Pays de l’Adour (UPPA) in Pau, France and the Christian-Albrechts University (CAU) in Kiel, Germany. In the course of this international collaboration, bio-analytical methods for the quantitative and qualitative analysis of labelled peptides and proteins were developed, which were based on the hyphenation of chromatography with mass spectrometry. Peptides and protein digests were lanthanide labelled using DOTA-based compounds according to an optimised protocol. Separation on the peptide level was performed using IP-RP-nanoHPLC. Complementary data sets were acquired using MALDI-MS for identification and ICP-MS for quantification. In this context, an online precleaning step was developed and implemented in the nanoHPLC separation routine, which allowed for effective removal of excess reagents. This lead to lowered metal backgrounds during ICP-MS measurements and thus better data interpretability, while guarding peptide recovery at a maximum level. An alternative offline purification using solid phase extraction (SPE) resulted in important peptide losses and can be considered unsuitable for quantitative analysis. Additives to the nanoHPLC eluents, such as HFBA and EDTA were tested and not deemed beneficial for the analysis of normal peptide samples. HFBA can be reconsidered for special application on very hydrophilic peptide species. A set of labelled peptides was developed, which due to application of known quantities could be employed for quick and simple quantification of a low complexity digest sample. In addition this peptide set allowed for the reliable superposition of chromatograms, enabling sample comparability especially for complementary ICP-MS and MALDI-MS data. Experiments for application of fsLA-ICP-MS on MALDI-MS target plates were conducted and showed very promising results. For this purpose, samples that were already identified using MALDI-MS were supposed to be remeasured using fsLA-ICP-MS. First quantification attempts on the modified steel target plate were successful and in the range of expectance. Adjusted parameters for MALDI-MS allowed for proper peptide identifications
Livros sobre o assunto "Extraction en phase solide – Purification":
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Liška, Igor. Theoretical aspects of the use of solid phase extraction in analysis of trace organic contaminant in water. Bratislava: Water Research Institute, 1994.
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F, Jenkins Thomas, e Cold Regions Research and Engineering Laboratory (U.S.), eds. Evaluation of clean solid phases for extraction of nitroaromatics and nitramines from water. [Hanover, N.H.]: US Army Corps of Engineers, Cold Regions Research and Engineering Laboratory, 1995.
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United States. Environmental Protection Agency. Office of Solid Waste and Emergency Response., Tetra Tech EM Inc e GeoTrans Inc, eds. Multi-phase extraction: State-of-the-art-practice. [Washington, D.C.]: U.S. Environmental Protection Agency, Solid Waste and Emergency Response, 1999.
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Poole, Colin F. Solid-Phase Extraction. Elsevier, 2019.
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Multi-phase extraction: State-of-the-art-practice. [Washington, D.C.]: U.S. Environmental Protection Agency, Solid Waste and Emergency Response, 1999.
Capítulos de livros sobre o assunto "Extraction en phase solide – Purification":
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Vahan Kilikian, Beatriz, Telma Teixeira Franco, Jane S. R. Coimbra, Antonio J. A. Meirelles, Adalberto Pessoa e Adamu Muhammad Alhaji. "Liquid–Liquid Extraction in Aqueous Two-Phase Systems". In Purification of Biotechnological Products, 155–80. Boca Raton: CRC Press, 2024. http://dx.doi.org/10.1201/9781032726823-7.
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Brandenbusch, Christoph, Tim Zeiner e Juliane Merz. "CHAPTER 16. Intensification of Aqueous Two-phase Extraction for Protein Purification". In Intensification of Biobased Processes, 344–64. Cambridge: Royal Society of Chemistry, 2018. http://dx.doi.org/10.1039/9781788010320-00344.
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Zhou, Zhiquan, Yan Ren, Kaikai Ye, Yuqing Niu, Jiayu Zhang, Shu Meng, Shaohui Kang, Xiaohao Cao e Dabing Li. "Research on Re-extraction Technology for Uranium Refining Based on Fractionation Extraction". In Springer Proceedings in Physics, 355–66. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1023-6_32.
Resumo:
AbstractTBP extraction in nitric acid system is the core purification process of the wet method for uranium refining and conversion. Reextraction for uranium refining based on fractionation extraction was proposed, according to the characteristics and requirements of uranium refining extraction. The operation line and step line of reextraction were obtained through mathematical model, and the control law is explained. The reextraction bench test was carried out to investigate the stable operation and the concentration variation of the related components. The study shows that the reextraction process can run stably. After extraction, the concentration of uranium in organic phase can reach 120g/L, the extraction saturation can reach 96.7%, the concentration of uranium in raffinate is less than 10mg/L, and the concentration of impurity components is greatly reduced. Reextraction technology can facility the control of uranium refining extraction, which maintains the state of high saturation vs. low raffinate concentration.
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Harrison, Roger G., Paul W. Todd, Scott R. Rudge e Demetri P. Petrides. "Extraction". In Bioseparations Science and Engineering. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780195391817.003.0009.
Resumo:
Extraction is a process in which two phases come into contact with the objective of transferring a solute or particle from one phase to the other. For the separation and purification of biological products, the phases are most commonly immiscible liquids, and the solute is in soluble form. In certain instances, however, one phase is a liquid and the other phase is a solid; the extraction of caffeine from coffee beans is one example. Although most extractions in biotechnology involve the transfer of soluble bioproducts, organelles and cells have at times been transferred between phases. An organic solvent is often used as the extracting liquid when the solute to be extracted is stable in the organic solvent, typical examples being low molecular weight antibiotics. It is usually not feasible to extract proteins with organic solvents, since proteins are often denatured or degraded as a result of contact with the organic solvent. Proteins can often be successfully extracted by means of two immiscible liquid phases that consist of solutions of two water-soluble but incompatible polymers, or one polymer plus a high concentration of certain salts. Extraction usually comes early in the purification process for a bioproduct and typically would precede a high-resolution step such as chromatography. Extraction is often advantageous because it can bring about a significant reduction in volume and/or can separate the desired product from cells or cell debris. It is desirable to reduce the volume as soon as possible in the process, since large volumes typically lead to large costs. The extractions of interest in the purification of biotechnological and pharmaceutical products are mainly liquid-to-liquid, and this is the emphasis in this chapter. The basic definitions and principles of extraction are developed first, followed by an explanation of scale-up and design procedures for the extractors most commonly used for bioproducts. After completing this chapter, the reader should be able to do the following: • Define and use key constants such as the partition coefficient, solvent-to-feed ratio, and extraction factor. • Explain the factors that affect the partitioning of biomolecules.
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Bodennec, Jacques, e Jacques Portoukalian. "Lipid Classes: Purification by Solid-Phase Extraction". In Encyclopedia of Chromatography, 970–72. CRC Press, 2005. http://dx.doi.org/10.1201/noe0824727857-203.
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Avino, Pasquale, Ivan Notardonato e Mario Vincenzo Russo. "A Review of the Analytical Methods Based on Chromatography for Analyzing Glyphosate in Foods". In Pests, Weeds and Diseases in Agricultural Crop and Animal Husbandry Production. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.92810.
Resumo:
Glyphosate is a pesticide widely used in agriculture, horticulture, and silviculture as well as around homes and gardens. It was introduced by Monsanto in the early 1970s, and it is a broad spectrum, nonselective, post-emergence herbicide that inhibits plants’ shikimic acid pathway. Glyphosate is considered as “difficult herbicide” in terms of trace analysis. It has low molecular weight, low volatility, thermal lability, and good water solubility. These properties cause problems in its extraction, purification, and detection. The determination often requires additional processes that may allow quantification by chromatographic methods. Several analytical procedures have been developed based on solid-phase extraction, ion-exchange chromatography, or matrix solid phase dispersion. Most published methods involve liquid extraction followed by clean-up. This review would like to revise the literature on this issue discussing the relevant chromatographic methods reported in the literature in terms of analytical parameters for analyzing such compound in food chain.
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Curran, Dennis P., Sabine Hadidaꝉ, Armido Studer╪, Mu He§, Sun-Young Kim, Zhiyong Luo, Mats Larhed*, Anders Hallberg* e Bruno Linclau. "Experimental techniques in fluorous synthesis: a user’s guide". In Combinatorial Chemistry, 327–52. Oxford University PressOxford, 2000. http://dx.doi.org/10.1093/oso/9780199637546.003.0011.
Resumo:
Abstract In discovery research, the ‘reaction’ stage of a synthetic step and the ‘separation’ stage have traditionally been uncoupled. Reactions are executed and then reaction mixtures are purified by using trial and error (or, perhaps more commonly, experience) to select a suitable purification technique. Experimental techniques for combinatorial chemistry and parallel synthesis need to be simple, fast, and efficient, and these needs have precipitated the development of a number of general new approaches for making small organic molecules (1, 2) that couple reaction and separation at strategy level. The goal of strategy level separation is to plan a reaction that can be purified simply by workup (3, 4). In other words, the desired product of a reaction will partition into (or be a part of) one phase, while all the other products of the reaction will partition into another phase. The commonly used phases for organic separations are the gas phase, the water phase, the organic liquid phase, and the solid phase, and these phases can be separated by evaporation, extraction, filtration (used alone or in combination, as appropriate). A number of imaginative and effective ‘workup level’ separation techniques have recently been introduced that take advantage of these different phases (3).
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Bodennec, Jacques, Gérard Brichon, Georges Zwingelstein e Jacques Portoukalian. "Purification of Sphingolipid Classes by Solid-Phase Extraction with Aminopropyl and Weak Cation Exchanger Cartridges". In Methods in Enzymology, 101–14. Elsevier, 2000. http://dx.doi.org/10.1016/s0076-6879(00)12902-7.
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Harris, E. L. V. "Concentration of the extract". In Protein Purification Techniques. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780199636747.003.0010.
Resumo:
A concentration step is frequently required after a clarified solution of the protein has been obtained, in order to aid subsequent purification steps. This is particularly important when the protein is obtained in culture medium from cells (e.g. bacteria or tissue culture cells). Concentration of the protein solution results in a decreased volume, as well as a higher protein concentration. Clearly a smaller volume of solution is easier to handle in subsequent steps, such as precipitation or loading onto a chromatography column. Higher protein concentration minimize protein losses by non-specific adsorption to container walls or column matrices. In addition many subsequent purification steps require a minimum protein concentration to be effective, for example, precipitation is more efficient at concentrations above 100 μg/ml, whilst for adsorption chromatography (e.g. ion exchange or affinity) the concentration of protein must be greater than the dissociation constant. Concentration is achieved by removal of water and other small molecules: (a) By addition of a dry matrix polymer with pores that are too small to allow entry of the large protein molecules (Section 2). (b) By removal of the small molecules through a semi-permeable membrane which will not allow the large molecules through (i.e. ultrafiltration, Section 3). (c) By removal of water in vacua (i.e. lyophilization, Section 4). Precipitation can also be used to concentrate proteins if the pellet is redissolved in a smaller volume, and in addition often results in some degree of purification of the protein of interest. However, as mentioned above precipitation is more effective if the total protein concentration is above 100 μg/ml (see Section 6). Two-phase aqueous extraction can also be used to concentrate the protein, with an associated degree of purification (see Section 7). This is one of the simplest and quickest methods of concentrating solutions of proteins, requiring minimal apparatus. A dry matrix polymer, such as Sephadex, is added to the protein solution and allowed to absorb the water and other small molecules; the pores within the matrix are too small to allow the protein to be absorbed.
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Berne, P. F., e S. Doublié. "Molecular Biology for Structural Biology". In Crystallization of Nucleic Acids and Proteins. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780199636792.003.0007.
Resumo:
The number of published 3D structures has increased exponentially in the last decade and the resulting mass of structural data has contributed significantly to the understanding of mechanisms underlying the biology of living cells. However, these mechanisms are so complex that structural biologists face still greater challenges, such as the study of higher-order functional complexes. As an example, we can mention the protein complexes that assemble around activated growth factor receptors to allow the transduction of extracellular signals through the membrane and inside the cell (1). Because of their diverse intrinsic properties, proteins exhibit variable difficulty for structural biology studies. Before the rise of recombinant expression methods, only a minority of protein structures were determined, representing mainly favourable cases: proteins of high abundance in their natural source which could be purified and crystallized, in contrast to rare proteins that were often refractory to crystallization. The advent of methods for recombinant protein overexpression was a breakthrough in this area. It was followed by an increasing number of publications describing the crystallization of proteins, not under their native form, but in modified versions after sequence engineering. First we will consider the classical use of molecular biology applied to optimize the expression system for a recombinant protein for structural biology, without modification of its sequence. In the second part, we will deal with molecular biology procedures aimed at engineering the properties of a protein through sequence modifications in order to make its crystallization possible. In the last part we will give an example where molecular biology can help solve a crystallographic problem, namely that of phase determination by introducing anomalous scatterers (e.g. selenium atoms) into the protein of interest. Whenever extraction of a protein from its natural source appears unsuitable for structural studies, molecular biology resources can be brought in, initially aiming at choosing and setting up an appropriate expression system. This initial approach could involve comparing various expression hosts and vectors and deciding if the protein is to be produced as a fusion to facilitate its purification.
Trabalhos de conferências sobre o assunto "Extraction en phase solide – Purification":
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Chen, Xiaoguo, Shenghu Zhang, Yang Zhang e Bangding Xiao. "Purification of Microcystin-LR by Solid-Phase Extraction Procedure". In 2009 3rd International Conference on Bioinformatics and Biomedical Engineering (iCBBE). IEEE, 2009. http://dx.doi.org/10.1109/icbbe.2009.5163264.
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Nguyen, ThaiHuu, e Qiao Lin. "Thermally Responsive Aptamer Surfaces for Microfluidic Sample Preparation". In 2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2008. http://dx.doi.org/10.1115/micronano2008-70264.
Resumo:
For many bioanalytical systems, the quality of the sample under scrutiny greatly affects the success of its analysis by the analytical instrument. Thus, sample preparatory techniques such as solid-phase extraction (SPE), purification and concentration are used to improve the quality of the sample before introduction into the equipment. This work overviews our effort in developing microdevices which exploit thermally responsive aptamers for biomolecular sample extraction, purification and concentration. We demonstrate the feasibility of this approach with a model system which consists of an adenosine monophosphate (AMP) analyte and adenosine triphosphate derived aptamer. Through systematic experimentation, we demonstrate the extraction and enrichment of AMP at physiologically relevant concentrations, release of AMP and regeneration of the aptamer through thermal stimulation, and detection of AMP by either fluorescence or mass spectrometry. In addition, completely aqueous operation of the device eliminates the use of potentially harsh reagents.
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Chenming (Mike) Zhang, Fabricio Medina-Bolivar e Carole Cramer. "Purification of Ricin B from Tobacco Hairy Root Culture Medium by Aqueous Two-Phase Extraction". In 2004, Ottawa, Canada August 1 - 4, 2004. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2004. http://dx.doi.org/10.13031/2013.17029.
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Morales, Mercedes C., e Jeffrey D. Zahn. "Development of a Diffusion Limited Microfluidic Module for DNA Purification via Phenol Extraction". In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68086.
Resumo:
Purification of Deoxyribonucleic acid (DNA) by organic-aqueous liquid extraction, also called phenol extraction, is a standard technique commonly utilized in biology laboratories. In order to minimize interaction energies, membrane components and proteins naturally partition to the organic (phenol) phase while the DNA stays in the aqueous phase, where it can be easily removed. In recent years, microfluidics has become a driving force toward more efficient and autonomous platforms for fluid based diagnostics, chemical reaction chambers, separation and preparation of biological materials. In this work, fabrication, and performance of a long microfluidic device for DNA extraction are presented. The devices were fabricated using soft lithography to transfer lithographically defined features into a PDMS structure via replica molding. Stratified-flow experiments using a rhodamine dye conjugated bovine serum albumin protein (BSA) in an aqueous phase were conducted to demonstrate the ability to remove proteins from the aqueous phase into the phenol phase. Additionally, the study of BSA partitioning and DNA isolation in a two-phase system under stratified flow condition were presented, separately and conjunctly. Finally, protein partitioning and DNA recovery obtained with this device could be compared with other types of mixing and extraction such as mixing by droplet formation and electrohydrodynamic (EHD) instability.
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He, Fei, e Qiang Wan. "Study on Purification of U Scraps in Continuous Countercurrent Extractor". In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-66336.
Resumo:
In this paper, the feasibility of continuous countercurrent extractor (CCE) applied in extraction of U scraps rather than mixer-settler was studied. Effects of rotation Reynolds number, residence time on extraction and reverse extraction efficiency were investigated respectively. During the process, impurity content in raw material had a slight effect on extraction. Under the optimum conditions of O/A phase ratio of 1.2 and rotation Reynolds number of 13824, extraction degree of scrap pellet solution and alkalescence dreg lixivium were good with the residence time of 19 min and 26 min respectively. Under the best reverse extraction conditions of A/O phase ratio of 1.2, rotation Reynolds number of 23128 and residence time of 19 min, two kinds of raw material liquid mentioned as above could get better reverse extraction efficiency, while uranium concentration of raffinate phase and impurity content of reverse extract phase satisfied the technological requirement. This study verified the feasibility of CCE developed for purification of U scraps, identified the operation parameter, and provided an experimental basis for industrial expansion in the future.
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Kalyakin, S. N., V. I. Kuzmin e M. A. Mulagaleeva. "EXTRACTION OF HEAVY GROUP LANTHANIDES BY MIXTURES OF BINARY EXTRACTANTS AND SOLVATING REAGENTS". In XVI INTERNATIONAL CONFERENCE "METALLURGY OF NON-FERROUS, RARE AND NOBLE METALS" named after corresponding member of the RAS Gennady Leonidovich PASHKOVA. Krasnoyarsk Science and Technology City Hall, 2023. http://dx.doi.org/10.47813/sfu.mnfrpm.2023.140-147.
Resumo:
Currently, phosphorus-containing cation-exchange organic extractants, due to their greatest selectivity, are the most commonly used reagents in the separation of rare earth metals (REM) by extraction methods. However, their use in the isolation and purification of individual REM is associated with high costs of reagents (mineral acids and bases). The addition of a cation-exchange extractant to a mixture of cation-exchange extractants makes it possible to change the nature of the process from cation exchange to extraction of the neutral salt, creating new opportunities for re-extraction of REM and reducing the consumption of extractants. Such a class of extractants is called binary extractants (BE). In the presented work, the following cation exchange organic reagents were used: 2-ethylhexyl-mono-2-ethylhexyl ether of phosphonic acid (EHEHPА) and di-(2- ethylhexyl)phosphoric acid DEHPA, and high-molecular organic amine - as an anion exchange reagent. Heavy group lanthanides (Dy – Lu) tend to form precipitation in the organic phase and are characterized by high distribution coefficients (DLn). We have previously established that alkylamine nitrates can act as effective solvating additives to increase the solubility in the organic phase of salts of reagents used with REM.
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Purdon, A. D., e J. B. Smith. "RELEASE AND TRANSACYLATION OF ARACHIDONATE FROM A COMMON POOL OF 1-ACYL-2-ARACHIDONOYL GLYCEROPHOSPHOCHOLINE IN HUMAN PLATELETS". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643391.
Resumo:
We have previously shown that the main source of arachidonate in thrombin-stimulated human platelets is 1-acyl-2-arachidonoyl (AA) glycerophosphocholine (GPC) and release of 3H-AA from this phospholipid also was correlated with increased 3H-AA in ether phospholipid. This ATP independent transfer of 3H-AA from 1,2 diacyl GPC to ether phospholipid (transacylation) also occurs in resting cells. Human platelets in 1/10 volume of plasma (ACD anticoagulant, pH 6.5) were radiolabelled with 3H-AA for 60 min at 37°C and then exogenous 3H-AA was removed by gel filtration into Tyrode's buffer, pH 7.4, 0.2% albumin. These radiolabelled cells were incubated in the absence of exogenous 3H-AA for four hours followed by Bligh and Dyer extraction and thin layer chromatography purification of phospholipids. 3H-AA in 1,2 diacyl GPC was found to decrease by over 20% and increase substantially in 1-0-alkyl-2-acyl GPC and 1-0-alk-1'-enyl-2-acyl glycerophospho ethanolamine (GPE), In this same time interval the mass of AA released by thrombin (5 U/ml, 10 min, 37°C, no stirring)in the presence of BIT 775C and measured by GLC, stayed the same (30 nmoles/109 cells), however, the specific activity decreased. Using reverse phase HPLC to resolve diradylglycerobenzoate derivatives of phospholipids: acylation, deacylation, and transacylation were observed for individual AA-containing molecular species of phospholipid, including those with an unsaturated fatty acid at sn-1. In particular the radiolabellinq of the 1-unsaturate-2-arachidonoyl GPC correlated with the specific activity of the 3H-AA released by stimulation with thrombin. Furthermore, 1-arachidonoyl-2-3H-arachidonoyl GPC was completely deacylated while 50 % of its mass remained. This contrasted with 16:0, and 18:0-2-arachidonoyl GPC in which the specific activity remained the same before and after deacylation. We conclude that deacylation of AA-containing molecular species of 1,2 diacyl GPC in stimulated cells includes molecular species which are also a source of arachidonic acid for transacylation reactions.