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1
Tungkananuruk, Nipon. "Extraction ion-pair complexes using solid-liquid systems." Thesis, Queen's University Belfast, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317121.
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Zimmermann, Benno F. "Proanthocyanidins in barley and malt analyzed by pressurized liquid extraction, solid-phase extraction and HPLC." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=979090113.
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Möller, Kristina. "Molecularly Imprinted Solid-Phase Extraction and Liquid Chromatography for Biological Samples." Doctoral thesis, Stockholms universitet, Institutionen för analytisk kemi, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1042.
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This thesis focuses on the use of molecularly imprinted polymers as selective sorbents for solid-phase extraction (MISPE). The MISPE methods developed were mainly intended for use with biological samples, such as human urine and blood plasma. These body fluids are complex samples, which often need an effective clean-up step before analysis to reduce the levels of possible interfering substances from the matrix, especially if the analytes are present in trace amounts. Solid-phase extraction (SPE) is a well-established and routinely used method for clean-up and preconcentration of samples from diverse matrices. However, conventional SPE sorbents often lack selectivity, leading to co-extraction of interferences, which negatively affects the following detection method. One of the advantages of MISPE is the built-in selectivity for a target analyte, or class of structurally related analytes, enabling the efficient clean-up that is often required for biological samples. The built-in selectivity of MISPE originates from the preparation of a highly crosslinked copolymer network in the presence of an imprint molecule, i.e. the template. Subsequent removal of this template molecule leads to the creation of defined recognition sites, complementary to the shape and functionality of the template. In this work, molecularly imprinted polymers were synthesized for the first time for several types of target analytes, including diphosphate esters (Papers I-III) and a protein adduct (Paper IV) and evaluated as sorbents for solid-phase extraction. A MISPE method for extracting local anaesthetic drugs from human plasma was also evaluated (Paper V). The development of appropriate methods for using the prepared polymers to extract target analytes directly from body fluids, and the elucidation of factors that influence their performance, were major foci of all the work underlying this thesis. These are not straightforward tasks, since the recognition mechanism of the material is often based on polar interactions, which are not favoured in aqueous environments. In such cases, non-selective adsorption of the analyte(s) to the polymer surface often occurs. In order to use the MIP sorbent most effectively it is important to suppress this non-selective adsorption, without disrupting the selective adsorption of the target analyte(s) to the imprints. Generally in these studies, this strong analyte-polymer surface interaction could be repressed, and selective adsorption enhanced, by carefully optimising the conditions for washing the sorbent, in terms of organic solvent volumes, solvent polarity and the addition of an ionic modifier. The sample matrix, mainly urine, was found to strongly decrease the capacity of the MIP. Hence, this effect was further investigated. It was found that the presence of NaCl in the sample negatively affected the recovery and repeatability of the method. Furthermore, these parameters could be improved by adjusting the sample pH. It was important to control the pH of the sample, in order both to achieve selective extraction and to increase the extraction recoveries. The selectivity of MISPE for the extraction of diphosphate esters from human urine was demonstrated by comparing its performance with that of a conventional SPE sorbent, a mixed-mode-anion exchanger (MAX). Due to its efficient clean-up, MISPE generated extracts that yielded less complex ion chromatograms in subsequent LC/ESI-MS analysis than extracts from the MAX cartridge. Due to its efficient clean-up, MISPE generated extracts that yielded less complex ion chromatograms in subsequent LC/ESI-MS analysis than extracts from the MAX cartridge. Signal suppression from the interfering co-eluting compounds was detected when the MAX extracts were analysed, which was not the case for the MISPE extracts. These findings show the importance of efficient and selective sample preparation, even if a selective detector is used. Development of LC/ESI-MS methods was also an extensive component of this work (Papers I-IV). Different chromatographic conditions have been evaluated for the optimal separation and detection of the investigated compounds. Use of ion-pairing agents and suitable HPLC columns (Hypercarb and C18 Aquasil) for the acidic, polar analytes, was found to give better retention and separation than use of conventional reversed-phase columns. To improve the selectivity and detectability further, selected ion monitoring (SIM) and selected reaction monitoring (SRM) acquisition modes were used for quantification of the investigated compounds. In summary, the aim of this work was to contribute to the knowledge of the recognition mechanisms of molecularly imprinted polymers in aqueous matrices, which is important for extending the use of MISPE for several types of bioanalytical applications.
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Menon, Sreejit Rajiv Menon. "Design and Development of 2-Functionalized Calix[4]arenes and Their Investigation in the Separation of Lanthanides." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1461715995.
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Slack, Gregory C. "Coupled solid phase extraction-supercritical fluid extraction on-line gas chromatography of explosives from water." Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-05042006-164508/.
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Shearer, Justin W. "Fundamental Studies With Functionalized Low Temperature Glassy Carbon In Liquid Chromatography, Solid-Liquid Extraction, And Capillary Electrophoresis." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1218477883.
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Möller, Kristina. "Molecularly imprinted solid-phase extraction and liquid chromatography/mass spectrometry for biological samples /." Stockholm : Department of Analytical Chemistry, Stockholm University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1042.
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Fernandez, Katherine Zegarra. "Cation-Calixarene derivatives : complexation studies and solid-liquid cation extraction from aqueous medium." Thesis, University of Surrey, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442668.
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Zimmermann, Benno F. [Verfasser]. "Proanthocyanidins in barley and malt analyzed by pressurized liquid extraction, solid-phase extraction and HPLC / Benno F Zimmermann." Aachen : Shaker, 2005. http://d-nb.info/979090113/34.
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Mills, Malcolm John. "Effective use of microbore LC with peak compression for the analysis of drugs in biological fluids." Thesis, University of Sunderland, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297131.
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Zegarra, Fernandez Katherine. "Cation-calixarene derivatives : solution complexation studies and solid-liquid cation extraction from aqueous medium." Thesis, University of Surrey, 2007. http://epubs.surrey.ac.uk/844074/.
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The work presented in this thesis is focused on the removal of ions from saline water using macrocyclic ligands. Calixarene derivatives were synthesised to target metal cations found in saline water, followed by the attachment of the macrocycles onto solid supports such as silicates in order to work in aqueous media. A general introduction is given covering i) existing methods of desalination, ii) main aspects and development of Supramolecular Chemistry and previous work done in this area. This Thesis investigate the complexation properties of synthetic macrocyclic ligands such as calix[5]arene derivatives L1 and L2 towards metal cations in dipolar aprotic and protic media (MeCN and MeOH) at 298.15 K.1H NMR studies were used to investigate the interaction of the receptors 5, 11, 17,23,29p-tert-butyl-31, 32, 33, 34,35 penta-ethanoate calix[5]arene, L1 and 5, 11, 17,23,29p-tert-butyl-31, 32, 33, 34,35 penta-diethylacetamide, L2 with several metals cations. Conductance measurements clearly demonstrated that 1:1 and 2:1 metal cation: ligand stoichiometry are found with these metal cations in acetonitrile. The thermodynamic of complexation of Li and L2 with metal cations in acetonitrile and methanol at 298.15 K was derived from titration calorimetry and those derived by potentiometry. L1 and L2 behave in a similar fashion for alkaline-earth metal cations with a higher stability constant for Ba2+ cation relative to other metal cations in acetonitrile and methanol. The calix[4]arene acetamide was attached onto a modified silica as solid support. This was followed by the characterisation of the material and experimental work to establish the uptaking capacities under different conditions. Final conclusions and suggestions for further research in this area are given.
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Al, Anqah Laila. "Trace element contaminants in the Kuwait water production system." Thesis, Brunel University, 1996. http://bura.brunel.ac.uk/handle/2438/5012.
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Fresh water in Kuwait is produced by non- conventional methods. About 95% of this water comes from desalinated seawater using multi-stage flash distillation technique and the remainder comes from underground brackish water. The blended water containes organic, inorganic and trace metal impurities within the recommended international standard limits. The purpose of this work is to identify the source of selected trace metals present in the drinking water in Kuwait. Chromium, copper, iron, lead, manganese, nickel, vanadium and zinc have been analysed using atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectroscopy (ICPMS). Efforts were made to improve the preconcentration of the selected metals and their separation from the high concentration of salts in seawater which affect the accuracy and cause major interference in the analysis. Solid-liquid extraction (chelex-100 resin) and liquid-liquid extraction (methyl iso-butyl ketone and freon) with and without back-extraction into nitric acid were investigated. Liquid-liquid extraction without back-extraction proved to give optimum recovery of the selected metals. Results confirmed that both AAS and ICP-MS are suitable for the analysis of trace metals in Kuwait's waters. Although AAS technique proved to be more accurate in analysing the selected metals than ICP-MS, the latter was adopted since its accuracy is acceptable (1.1-4.4%) and it is easier and faster than the former technique. The study revealed that the source of copper, iron, nickel and zinc is the construction materials of the distillation plants, while the source of lead and vanadium is the brackish water. Manganese and chromium concentrations are very low in all sources. No direct relationship between the metal concentration in the seawater and the distillate could be deduced.
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Saini, Gaurav. "Functionalization of Diamond and Its Application in High Performance Liquid Chromatography and Solid Phase Extraction." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2797.
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The primary focus of my work was to chemically functionalize diamond as normal and reversed phases for solid phase extraction (SPE) and high performance liquid chromatography (HPLC). Diamond was functionalized with -NH2 groups via self-limiting adsorption of an amine-containing polymer, polyallylamine (PAAm), onto oxidized diamond particles. The chemical stability of these particles was improved by thermal curing or chemical crosslinking with 1,2,5,6-diepoxycyclooctane. The reversed phase material for SPE was synthesized by reacting amine-functionalized diamond particles with long chain alkyl and a perfluorinated isocyanate. Unlike commercially available silica, functionalized diamond particles were stable under extreme pH conditions (pH 0-14). Functionalized diamond particles were used for SPE, although their lack of porosity resulted in poor analyte capacity. To create materials with greater surface area, core-shell diamond particles were synthesized via layer-by-layer deposition of PAAm and nanodiamond onto solid microdiamond. These particles had higher surface areas than solid diamond particles, and their application in SPE and HPLC was demonstrated. As a related project, I demonstrated microlens array patterning (MAP) for selective adsorption of PAAm during microarray fabrication. Initially, alkyl monolayer terminated silicon surfaces were photopatterned with thousands of wells using a microlens array. PAAm was then deposited in the presence of a cationic surfactant to limit nonspecific adsorption of PAAm. Finally, reactions of selectively adsorbed PAAm were shown with glutaric anhydride, phenylenediisothiocyanate, biotin NHS-ester and an oligonucleotide (DNA). My third project concerned the synthesis of an abrasion resistant hydrophobic coating on the surface of nylon and silicon oxide substrates using chemical vapor deposition (CVD) of two silanes. The synthesis consists of four steps: 1) plasma oxidation of the substrate, 2) treatment with 3-isocyanatopropyltrimethoxysilane, 3) exposure of the treated surfaces to water vapors, and 4) treatment with a perfluorinated silane to make the surfaces hydrophobic. The coating is not visible to the eye and does not change the feel of the surface. Time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry, contact angle goniometry, scanning electron microscopy (SEM), environmental scanning electron microscopy (ESEM), Rutherford backscattering spectroscopy (RBS) and nuclear reaction analysis (NRA) were used to characterize the resulting materials.
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Ma, Wai Tang. "Analysis of polar nitroaromatics in groundwater by using solid-phase extraction and liquid chromatography-mass spectrometry." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/581.
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Martin, Danica Paige. "Optimization of a Method for the Extraction of Drugs of Abuse from Wastewater." Bowling Green State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1617014087323429.
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Martins, Ana Margarida Ferreira. "Phycobiliproteins extraction from the red macroalga Gracilaria vermiculophylla." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/19031.
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Mestrado em BiotecnologiaRecentemente, o interesse pelos produtos obtidos de fontes naturais tem crescido em relação aos produtos sintéticos. Assim sendo, produtos extraídos de fontes naturais têm sido alvo de especial atenção pela indústria e pelo meio académico. Alguns desses compostos interessantes podem ser encontrados nas macroalgas vermelhas, nomeadamente a R-ficoeritrina, uma das ficobiliproteínas mais valiosas presentes na macroalga. Contudo, a maior dificuldade encontrada na extração e purificação desta proteína fotossintética está associada à necessidade de metodologias de extração e purificação mais eficazes, de mais baixo impacto económico e ambiental, capaz de remover as proteínas da biomassa, mantendo a sua estrutura conformacional e principais atividades. Neste trabalho, um conjunto de parâmetros experimentais de extração foram otimizados, nomeadamente o solvente em causa. Várias soluções aquosas de líquidos iónicos foram testadas na extração de ficobiliproteínas a partir da macroalga vermelha Gracilaria vermiculophylla. Depois de otimizado o tempo de extração, a razão sólido-líquido, o solvente, pH e concentração de solvente, foi possível chegar a uma metodologia capaz de extrair mais 30% de ficobiliproteínas quando comparado com o método convencional reportado na literatura.
In the past few years, there has been an increased demand for natural compounds over the synthetic ones. Thus, products extracted from natural sources have gained significant interest among industries and academia. Several of these interesting compounds are present in red macroalgae namely R-phycoerythrin, a phycobiliprotein. However, the major drawback is associated with the demand for more effective, with low economic and environmental impact extraction and purification methodology capable to remove the protein from the biomass, while maintaining its structure conformation and main activities. Therefore, the search for efficient extraction technologies is of utmost importance. In this work, a set of different parameters of extraction was optimized, such as the solvent used. Aqueous solutions of ionic liquids were screened for the phycobiliproteins extraction from the Gracilaria vermiculophylla. Once optimized the time of extraction, the solid-liquid ratio, the solvent, the solvent concentration, and the pH, it was possible to design an efficient methodology capable to enhance the phycobiliproteins extraction in 30% when compared with the conventional extraction methodology.
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Adaway, Joanne E., Mirko Peitzsch, and Brian G. Keevil. "A novel method for the measurement of plasma metanephrines using online solid phase extraction-liquid chromatography tandem mass spectrometry." Sage, 2015. https://tud.qucosa.de/id/qucosa%3A35429.
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Background: Measurement of plasma metanephrine, normetanephrine and 3-methoxytyramine is useful in the diagnosis of phaeochromocytomas, but many assays require a large volume of plasma due to poor assay sensitivity, and often require lengthy sample preparation. Our aim was to develop a method for measurement of plasma metanephrines using a small sample volume with minimal hands-on preparation. Methods: Samples were deproteinised using 10 K spin filters prior to online solid phase extraction using a Waters Acquity UPLC Online SPE Manager (Waters, Manchester, UK) coupled to a Waters Xevo TQ-S mass spectrometer (Waters, Manchester, UK). The assay was validated and results compared to a previously published method. Results: We achieved a limit of quantification of 37.5 pmol/L for metanephrine and 3-methoxytyramine and 75 pmol/L for normetanephrine using only 150 mL of sample. The assay was linear up to 30,000 pmol/L for all analytes and in a method comparison study results showed good agreement with a previously published LC-MS/MS assay. Conclusions: We have developed a simple method for measurement of plasma metanephrine, normetanephrine and 3-methoxytyramine using only 150 mL of sample. There is minimal hands-on sample preparation required and the assay is suitable for routine use in a clinical laboratory.
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Guokaitė, Gabrielė. "Antidepresantų amitriptilino ir venlafaksino mišinio išskyrimo iš kraujo plazmos optimalių sąlygų nustatymas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140618_215636-47231.
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Atlikta mokslinių literatūros šaltinių apžvalga. Tiriamųjų medžiagų identifikavimui ir kiekybinei analizei pritaikyta ir validuota efektyvioji skysčių chromatografija. Antidepresantų mišinys išskirtas iš kraujo plazmos kietos fazės ekstrakcijos metodu. KFE metodas optimizuotas keičiant eliuentą ir eliuento pH. Atliktas optimizacijos sąlygų palyginimas. Nustatyti 3 organiniai tirpikliai, kuriais efektyviausiai eliuuojamos sorbente sulaikytos tiriamosios medžiagos bei gauti statistiškai patikimi rezultatai (p>0,05) : 2 proc. etano rūgšties tirpalas 100 proc. metanolyje, 2 proc. etano rūgšties tirpalas 80 proc. metanolyje ir 2 proc. metano rūgšties tirpalas 100 proc. metanolyje.In this thesis was performed research of scientific literature. Applied and validated high performance liquid chromatography for identification and quantification of target compounds. Antidepressant mixture extracted from blood plasma samples using LLE and SPE methods. SPE method was optimized by changing the elutor and its pH. Three organic solvents were determined, which best elute target compounds from sorbent and show statistical confidence (p>0,05): 2 proc. acetic acid in 100 proc. methanol solution, 2 proc. acetic acid in 80 proc. methanol solution and 2 proc. formic acid in 100 proc. methanol solution.
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Zhou, Ling. "DEVELOPMENT OF A UNIVERSAL POLYMERIC STATIONARY PHASE FOR SOLID PHASE EXTRACTION AND AN IONIC LIQUID MOBILE PHASE MODIFIER FOR SEPARATION OF NATIVE PROTEINS BY LIQUID CHROMATOGRAPHY." Miami University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=miami1371503762.
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Harun, Norlida. "Application of molecularly imprinted solid phase extraction, enzyme-linked immunosorbent assay and liquid chromatography tandem mass spectrometry to forensic toxicology." Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/1992/.
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The rapid growth of ketamine and amphetamine misuse worldwide has led to the development of methods for the detection and analysis of ketamine and amphetamines in biological specimens. Most methods previously developed in forensic toxicology for the detection of ketamine and amphetamines used GC-MS. The present work developed alternative methods based on LC-MS/MS. Ketamine was chosen as the drug of interest because there are no data currently available on the extent of ketamine abuse in Malaysia even though a large amount of ketamine has been seized by the Malaysian Royal Police, while amphetamines are the most widely abused synthetic drugs in South East Asia including Malaysia. The study addressed some of the challenges facing the forensic toxicologist, such as the need to use new technology (LC-MS/MS) and improve sensitivity and selectivity in forensic toxicology analysis through efficient sample preparation techniques. The general requirements of method validation, including as the parameters linearity, limit of detection (LOD) and Lower Limit of Quantification (LLOQ), recovery, precision and matrix effects were observed. Three main techniques were used in the study: enzyme-linked immunosorbent assay (ELISA), liquid chromatography tandem mass spectrometry (LC-MS/MS) and molecularly imprinted polymer solid phase extraction (MISPE). MISPE is a new extraction technique in forensic toxicology applied to biological samples. Initially work was carried out on the optimization, development and validation of the Neogen® ELISA for screening ketamine and norketamine in urine. The Neogen® ketamine ELISA kit was found to be adequately sensitive and precise for ketamine screening at a cut-off concentration of 25 ng/mL. The ELISA test was shown to be highly specific to ketamine and demonstrated minimal (2.1%) cross-reactivity to its main metabolite norketamine compared to ketamine. Subsequently, an LC–MS/MS confirmation method for ketamine and norketamine in urine samples was developed and validated with application of the method to urine samples from chronic ketamine users in Malaysia. The method demonstrated good linearity, LOD, LOQ, accuracy and precision and had acceptable matrix effects. The efficiency of ELISA as a screening method at cut-off of 25 ng/ml and LC-MS/MS as a confirmation method at 2 ng/ml was evaluated. These methods complemented each other and both ELISA and LC-MS methods were 100% sensitive and specific with no false positive results for ketamine and norketamine in urine samples. The results demonstrated that a combination of these two methods can be reliably used for routine screening and confirmation of ketamine and norketamine in urine specimens. Preliminary data from this study provided information on the concentrations of ketamine and norketamine typically found in urine samples collected from individuals frequenting pubs in Malaysia. The main work in this thesis involved molecularly imprinted polymer materials which were used as sorbents in solid phase extraction (MISPE). Ketamine was used as a model substance for novel in-house synthesised MIPs as no anti-ketamine MIP have previously been reported and because the ketamine structure is suitable for the synthesis of molecularly imprinted polymers. The study was intended to improve the selectivity and sensitivity of the extraction method (MISPE) prior to LC-MS/MS analysis. Evaluation of polymer imprinting was carried out using HPLC-UV. MIP extraction and LC-MS/MS analysis were applied to the determination of ketamine and norketamine in hair samples and compared with a conventional SPE-based method. MISPE extraction was selective and sensitive with fewer matrix effects than the conventional SPE method and could also be applied to norketamine, the principal metabolite of ketamine, due to the group-selective binding nature of the MIP, but not to structurally dissimilar analytes such as PCP and tiletamine. MISPE was superior to conventional SPE for trace detection of ketamine and norketamine in hair, in terms of improved sensitivity, lower limits of detection and reduced matrix effects. In addition, the commercial product Amphetamine SupelMIPTM was evaluated for identification of amphetamines in post mortem blood coupled with LC-MS/MS analysis. This work assessed whether the MIP, sold by the manufacturer for the extraction of amphetamines in urine, could also be used for whole blood. The results demonstrated that the MIP can be used successfully for the determination of amphetamines in post mortem blood. The recoveries of five amphetamines were lower than with a comparable GC-MS method but the LODs and LLOQs of the LC-MS/MS method were better and suitable for detection of low levels amphetamines in post mortem blood. Further optimisation is needed to develop an improved protein precipitation method prior to MISPE. Liquid Chromatography Electro-Spray Ionization Mass Spectrometry (LC–ESI-MS) was used with the MISPE and SPE methods for detection and quantification of ketamine, norketamine and amphetamines in urine, whole blood and hair samples. LC-ESI-MS was found to be easy to use and could detect lower concentrations of drugs and gave reproducible results for all the methods developed in this thesis.
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Alford, Shannon Recca. "Analytical method for detecting PCB derivatives at low levels in surface water samples by solid phase extraction-liquid chromatography/mass spectrometry." Mississippi State : Mississippi State University, 2005. http://library.msstate.edu/content/etd/show.asp?etd=etd-12142004-142520.
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Alford, Shannon Recca. "ANALYTICAL METHOD FOR DETECTING PCB DERIVATIVES AT LOW LEVELS IN SURFACE WATER SAMPLES BY SOLID PHASE EXTRACTION-LIQUID CHROMATOGRAPHY/ MASS SPECTROMETRY." MSSTATE, 2004. http://sun.library.msstate.edu/ETD-db/theses/available/etd-12142004-142520/.
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Polychlorinated biphenyls (PCBs) and their metabolic derivatives are ubiquitous environmental contaminants. These compounds are of concern because of their persistence and bioaccumulation in nature. PCBs and the hydroxylated metabolites have shown endocrine-disrupting activity. A method of detection in surface water samples is important to identify and quantify the environmental contamination. In this research we have attempted to develop a method of detection. Six representative polychloromethoxybiphenyls (PCMBs) were prepared. The corresponding polychlorobiphenylols, hydroxylated PCB metabolites (OH-PCBs), were prepared from the PCMBs. A method coupling solid phase extraction with liquid chromatography, on-line electrospray ionization, and mass spectrometry (SPE-LC/ESI/MS) was developed for detection of the OH-PCBs in distilled and surface water samples.
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Haupt, Petronella. "Effective solvent extraction of coal and subsequent separation processes." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08282007-113611.
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Thesis (M. Eng.)(Chemical Engineering)--University of Pretoria, 2006.Accompanied by a CD-ROM containing Matlab programs. Includes bibliographical references. Available on the Internet via the World Wide Web.
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Ismailov, Taner. "Quantification of resin acids, fatty acids and sterols in process and waste water from forest industry." Thesis, Karlstads universitet, Avdelningen för kemi och biomedicinsk vetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-28179.
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This work focuses on wood extractives in effluents from the CTMP plant at Skoghall Mill. Pulp and paper industry effluents contain mostly natural compounds which are part of the trees. They are toxic to aquatic life but harmless in nature, as they are present in low concentrations. Processing tons of wood, such as in a pulp mill, strongly increases the concentrations of the toxic compounds (Ali, M. and Sreekrishnan, T., 2001) which have to be treated before transferring to the aquatic environment.Extractives can be found in different forms, as micelles soluble in water, unprocessed in fibers or absorbed on the surface of fibers. It is important to know in which forms extractives are mostly present in the effluent, so that they can be treated more efficiently. It is desired to have extractives absorbed on the fibers and fibrils present in the waste water, so they can be separated from the water and treated separately, e.g. burned for energy recovery. Dissolved extractives complicate the oxygen transfer in an aerated biological treatment step with their surface active properties (Sandberg, 2012).The aim of this study is quantification of extractives on the fibers suspended in the waste water and extractives dissolved in the water. The distribution between the two forms is an important input when designing future effluent treatment. Wood extractives itself are a wide group with different compounds. This work focuses on the main groups present in waste water: resin acids, free and esterified fatty acids and, free and esterified sterols. These groups are analyzed in different process waters and waste water before the waste water treatment plant. The measured concentrations of extractives were as expected, higher in process and effluent waters, lower in white water. Most of the extract was dissolved in the water and unfortunately fiber samples contained very low concentration from the total extract in the samples.
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Kennard, Benjamin, Allison Cobble, Amy Gravitte, Kaleigh Galloway, Jen Kintner, Jennifer Hall, and Stacy C. Brown. "Quantification of Progesterone and 17-β Estradiol in Mouse Serum by Liquid Chromatography-Tandem Mass Spectrometry." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/asrf/2020/presentations/45.
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Quantification of progesterone and 17-β estradiol in mouse serum by liquid chromatography-tandem mass spectrometry
Authors:
Benjamin Kennard, Allison Cobble, Amy Gravitte, Keleigh Galloway, Jen Kintner, Jennifer Hall, Stacy Brown
Introduction: In the United States, Chlamydia trachomatis is a commonly appearing sexually transmitted infection1. It affects the U.S. healthcare system to a tune of about $500 million dollars annually2. In women, it generally appears asymptomatic and can lead to severe secondary complications such as pelvic inflammatory diseases or infertility1. Female sex hormones, estrogen and progesterone, are being identified to have a role in chlamydial infection. Specifically, this study aims to create quantification methods to detect levels of estrogen and progesterone in mice, infected with Chlamydia muridarum, plasma samples.
Methods: Progesterone samples were prepared using solid-liquid extraction (SLE+) cartridges with ethyl acetate as the elution solvent. Estradiol samples were prepared using liquid-liquid extraction (LLE) with methyl tert-butyl ether and subsequent derivatization with DMIS. Following sample preparation, hormones were quantified in samples using LC-MS/MS with a gradient elution of 1 mM ammonium fluoride in water and acetonitrile. The separation was achieved using a UCT C18 column (100 x 21.mm, 1.8 μm particle size) maintained at 50oC. The mass spectrometer was set up to isolate molecular ions for progesterone (m/z 315.0910) and derivatized estradiol (m/z 431.1835). Quantification was facilitated by the use of deuterium-labeled internal standards and their corresponding molecular ions in the mass spectrometer (d9-progesterone; m/z 324.1230 and d5-estradiol; m/z 436.2922).
Results: Several aspects of the assay presented have been optimized for maximum analyte recovery and analytical sensitivity, including column choice, mobile phase, derivatizing agents for estradiol, and extraction protocols for progesterone. The LC-MS/MS method was investigated for precision and accuracy over three separate days. The dynamic range of the progesterone assay was 5 – 100 ng/mL, with a limit of detection of 1 ng/mL. Likewise, the estradiol assay was linear in the range of 5 – 100 ng/mL, with a limit of detection of 0.5 ng/mL. The average precision, represented by % RSD was 0.74 – 8.5% and 6.3 – 13.4% for progesterone and estradiol, respectively. The accuracy of the method, represented by % error was 1.6 – 14.4% and 4.0 – 10.5% for progesterone and estradiol, respectively. Successful validation was defined as < 15% RSD and error (< 20% at the limit of quantification), per current FDA Guidelines.
Conclusions: The developed LC-MS/MS method is specific for progesterone and estradiol, and the extraction is suitable for preparation of mouse serum samples. This assay could be successfully applied to hormone quantification in mouse samples to support the investigation of the link between chlamydia infection and hormone levels in female animals.
References
1. Chlamydia - 2017 Sexually Transmitted Diseases Surveillance. https://www.cdc.gov/std/stats17/chlamydia.htm. Accessed October 23, 2018.
2. Owusu-Edusei K, Chesson HW, Gift TL, et al. The Estimated Direct Medical Cost of Selected Sexually Transmitted Infections in the United States, 2008. Sex Transm Dis. 2013;40(3):197-201. doi:10.1097/OLQ.0b013e318285c6d2
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Gobburi, Ashta Lakshmi Prasad. "An LC-MS/MS APPROACH FOR GANGLIOSIDES PROFILING IN BRAIN AND RETINAL TISSUE OF MICE: APPLICATION TO GLAUCOMA MICE AGE STUDIES." Cleveland State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=csu1521174979758726.
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Ballard, Tameshia Shaunt'a. "Optimizing the Extraction of Phenolic Antioxidant Compounds from Peanut Skins." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/28349.
Full textAbstract:
Peanut skins are a low-value byproduct of peanut blanching operations. They have been shown to contain significant levels of phenolic compounds with demonstrated antioxidant properties. The effects of two types of extraction methods: solid-liquid extraction (SLE) and microwave-assisted extraction (MAE) on the recovery of phenolic compounds from peanut skins were investigated. Response surface methodology was used to optimize extraction conditions based on total phenolic content (TPC), ORAC (oxygen radical absorbance capacity) activity and trans-resveratrol content. The protective effect of peanut skin extracts (PSE) against hydrogen peroxide (H₂O₂)-induced oxidative stress in human brain microvascular endothelial cells (HBMEC) and the effect of PSE on lipid oxidation in commercial peanut butter were also evaluated.
In the SLE method, EtOH was found to be the most efficient extraction solvent followed by MeOH, water and EA. Despite EtOH extracts having a higher TPC, samples extracted with MeOH demonstrated slightly higher ORAC activity. Resveratrol was identified in MeOH extracts but was not found in EtOH, water or EA extracts.
In the MAE procedure, the maximum predicted TPC under the optimized conditions was 144 mg phenols/g skins compared to 118 mg/g with SLE. The maximum predicted ORAC activity was 2789 μmol TE/g as opposed to 2149 μmol TE/g with the SLE method. MAE was able to extract more phenolic compounds (with higher antioxidant activity) in a faster time than the SLE procedure. In addition, resveratrol was identified in PSE derived from MAE although at relatively low levels.
PSE were found to have some protective effects against oxidative stress in HBMEC. Higher doses of PSE appeared to have a slightly cytotoxic effect. However, the data were highly variable which made it difficult to arrive at any definitive conclusions regarding the potential benefits of PSE in preventing oxidative damage to cells.
In the PB experiment, hexanal levels over the storage period were not high enough for the samples to be considered oxidized. However, hexanal values of PB samples treated with PSE were lower than the control throughout storage, which suggests that PSE may provide some protection against oxidation of PB.Ph. D.
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Pipes, Latisha C. "Detection of Illicit Drug Use in Blood: A Validation Study of Solid Phase Extraction Coupled with Liquid Chromatography and Tandem Mass Spectrometry." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1587613608312474.
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Abdulrheem, Ali Jamal. "Detection and Quantitation of Tetracycline Antibiotics in Agricultural Swine Wastes." TopSCHOLAR®, 2017. http://digitalcommons.wku.edu/theses/1931.
Full textAbstract:
The spread of tetracyclines through agricultural systems is causing the present bacteria to develop antibiotic resistance. The spread of this bacteria, as well as the tetracycline antibiotics in the environment is dangerous because these antibiotics pose health hazards for humans. The overuse of antibiotics, which are added to livestock feed, results in the antibiotics being released into the environment via animal feces. In this research, we have attempted to design an analytical method to isolate antibiotics from agricultural wastes with subsequent detection using liquid chromatography and mass spectrometry (LC-MS). The antibiotics investigated in this study were tetracycline, chlortetracycline, and oxytetracycline.
The analytical procedure involves mixing the agricultural samples with an organic solvent, such as methanol, which solubilizes these antibiotics. Next, samples are centrifuged to remove solid particulates. A polymeric weak cation cartridge was used to concentrate and separate the antibiotics from the unwanted organic chemical compounds found in the samples. The antibiotics were released with methanol with small amounts of acid and then detected and quantified using LC-MS and high performance liquid chromatography with a photodiode array detector (HPLC-PDA).
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Carvalho, Ana Rita Martins. "Monitorização de desreguladores endócrinos em águas de rede e águas residuais por SPE-UPLC-ESI-MS/MS. Empresa Portuguesa das Águas Livres (EPAL)." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5371.
Full textAbstract:
Engenharia do Ambiente - Instituto Superior de AgronomiaWater is an essential factor in the life and environmental issues and is a current topic of extreme importance to human health. Endocrine disrupters affect the endocrine system, significantly altering the vital functions in living beings. Thus, it is essential to undertake the monitoring of aquatic systems that exposure to and bioaccumulation of these compounds is mitigated. The objective of this study is to monitor the presence of ten EDC in 60 water samples distributed by EPAL and in 24 samples of wastewater from a treatment plant wastewater, using a method of analysis previously implemented in the company's central laboratory. The analysis method used in this work was to Ultra Performance Liquid Chromatography Efficiency associated with tandem mass spectrometry (UPLC-MS/MS) using the extraction technique as solid phase extraction (SPE) and as a method of ionization ionization electrospray (ESI). The compounds under study were estriol, bisphenol A, diethylstilbestrol, estrone, estradiol, ethinyl estradiol, progesterone, octylphenol, nonylphenol and mestranol, having the analytical limits calculated for each compound used in the identification and quantification of the same in water samples under study.
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Müller, Wolfram. "Extraction liquide-solide de cations métalliques par des cations amphiphiles." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20173/document.
Full textAbstract:
Dans le domaine de la séparation sélective pour le traitement et la valorisation des combustibles nucléaires usés, l'extraction liquide-liquide est largement utilisée au niveau industriel. Cependant dans le cadre des technologies nucléaires du futur, des procédés alternatifs de séparation sont recherchés. Notamment la précipitation sélective d'actinides par des tensioactifs cationiques en milieu aqueux (l'extraction liquide-solide étudié par Heckmann et al dans les années 80) apparaît comme une approche intéressante. Le principal avantage de cette technique, comparée à l'extraction liquide-liquide, est lié à la diminution du nombre d'étapes dans le processus comme le lavage du solvant ou la désextraction des métaux. De plus, c'est une technique sans solvant organique ce qui réduit considérablement la quantité de déchets contaminés. Pour ces travaux de thèse, nous avons utilisé des méthodes physico-chimiques pour mieux comprendre l'interaction spécifique entre le cation métallique et le tensioactif cationique. Nous avons tout d'abord analysé l'effet spécifique des contre-ions anioniques (Cl-, NO3-, C2O42-) provenant des acides utilisés; puis nous avons étudié finement l'introduction de cations alcalins monovalents et quelques cations multivalents sélectionnés (Cu2+, Zn2+, UO22+, Fe3+, Nd3+, Eu3+, Th4+) sur l'auto-assemblage et les propriétés structurels du tensioactif en variant les conditions thermodynamiques. Nous en avons conclu que l'adsorption d'un complexe anionique stable du métal, à l'interface des agrégats micellaires, influence fortement les paramètres d'agrégation du tensioactif et détermine ainsi les limites d'utilisation de cette technique de séparationIn the field of selective separation for recycling of spent nuclear fuel, liquid-liquid extraction processes are widely used (PUREX, DIAMEX …) in industrial scale. In order to guarantee a sustainable nuclear energy for the forthcoming generations, alternative reprocessing techniques are under development. One of them bases on the studies from Heckmann et al in the 80's and consists in selectively precipitating actinides from aqueous waste solutions by cationic surfactants (liquid-solid extraction). This technique has some interesting advantages over liquid-liquid extraction techniques, because several steps are omitted like stripping or solvent washing. Moreover, the amount of waste is decreased considerably, since no contaminated organic solvent is produced. In this thesis, we have carried out a physico-chemical study to understand the specific interactions between the metallic cations with the cationic surfactant. First, we have analysed the specific effect of the different counter-ions (Cl-, NO3-, C2O42-) and then the effect of alkaline cations on the structural properties of the surfactant aggregation in varying thermodynamical conditions. Finally, different multivalent cations (Cu2+, Zn2+, UO22+, Fe3+, Nd3+, Eu3+, Th4+) were considered; we have concluded that depending on the anionic complex of these metals formed in acidic media, we can observe either an adsorption at the micellar interface or not. This adsorption has a large influence of the surfactant aggregation properties and determines the limits of the application in term of ionic strength, temperature and surfactant concentration
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Silva, Liliana Cristina Vieira da. "Development of a sustainable method for the extraction of lycopene and β-carotene from food wastes." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15490.
Full textAbstract:
Mestrado em Biotecnologia - Biotecnologia AlimentarThe main objective of the present work is the study of a profitable process not only in the extraction and selective separation of lycopene and β-carotene, two compounds present in tomato, but also in its potential application to food industry wastes. This is one of the industries that produce larger amounts of wastes, which are rich in high value biomolecules with great economic interest. However, the conventional methods used to extract this kind of compounds are expensive which limits their application at large scale. Lycopene and βcarotene are carotenoids with high commercial value, known for their antioxidant activity and benefits to human health. Their biggest source is tomato, one of the world’s most consumed fruits, reason for which large quantities of waste is produced. This work focuses on the study of diverse solvents with a high potential to extract carotenoids from tomato, as well as the search for more environmentally benign solvents than those currently used to extract lycopene and β-carotene from biomass. Additionally, special attention was paid to the creation of a continuous process that would allow the fractionation of the compounds for further purification. Thus, the present work started with the extraction of both carotenoids using a wide range of solvents, namely, organic solvents, conventional salts, ionic liquids, polymers and surfactants. In this stage, each solvent was evaluated in what regards their capacity of extraction as well as their penetration ability in biomass. The results collected showed that an adequate selection of the solvents may lead to the complete extraction of both carotenoids in one single step, particularly acetone and tetrahydrofuran were the most effective ones. However, the general low penetration capacity of salts, ionic liquids, polymers and surfactants makes these solvents ineffective in the solid-liquid extraction process. As the organic solvents showed the highest capacity to extract lycopene and βcarotene, in particular tetrahydrofuran and acetone, the latter solvent used in the development process of fractionation, using to this by strategic use of solvents. This step was only successfully developed through the manipulation of the solubility of each compound in ethanol and n-hexane. The results confirmed the possibility of fractionating the target compounds using the correct addition order of the solvents. Approximately, 39 % of the β-carotene was dissolved in ethanol and about 64 % of lycopene was dissolved in n-hexane, thus indicating their separation for two different solvents which shows the selective character of the developed process without any prior stage optimization. This study revealed that the use of organic solvents leads to selective extraction of lycopene and β-carotene, allowing diminishing the numerous stages involved in conventional methods. At the end, it was possible to idealize a sustainable and of high industrial relevance integrated process, nevertheless existing the need for additional optimization studies in the future.
O principal objetivo do presente trabalho recai no estudo de um processo eficiente para a extração e fracionamento de licopeno e β-caroteno presentes no tomate, bem como na aplicação do processo a resíduos provenientes da indústria alimentar. Esta é uma das indústrias que produz das maiores quantidades de resíduos ricos em biomoléculas com valor acrescentado e com um elevado potencial económico. No entanto, os métodos convencionais para a extração deste tipo de compostos tornam-se dispendiosos, o que inviabiliza a sua aplicação em larga escala. O licopeno e o β-caroteno são carotenóides com elevado valor comercial, conhecidos pela sua atividade antioxidante e efeitos benéficos para a saúde humana. A sua maior fonte é o tomate, um dos frutos mundialmente mais consumidos, razão pela qual as quantidades de resíduos produzidos são consideráveis. Este trabalho centra-se no desenvolvimento de um processo que permita a extração e fracionamento eficientes destes carotenóides a partir do tomate, considerando o uso de solventes mais benignos que os estudados até ao momento. Adicionalmente, foi igualmente desenvolvido o processo de fracionamento em contínuo, considerando a futura aplicação industrial do mesmo. Assim, iniciou-se o presente trabalho com a extração destes dois carotenóides utilizando um conjunto de solventes comuns e alternativos, nomeadamente, solventes orgânicos, sais convencionais, líquidos iónicos, polímeros e surfatantes. Nesta etapa avaliou-se a capacidade de extração de cada um dos solventes. Os resultados obtidos demonstraram que uma seleção adequada do solvente pode conduzir à extração completa dos dois carotenóides numa única etapa de extração, sendo que a acetona e o tetrahidrofurano se revelaram os mais eficazes, sendo os sais, líquidos iónicos, polímeros e surfatantes pouco eficazes no processo de extração sólido-líquido, pela sua geral baixa capacidade de penetração na biomassa. Após demonstrar a elevada capacidade dos solventes orgânicos na extração do licopeno e β-caroteno, nomeadamente tetrahidrofurano e acetona, este último solvente foi usado no desenvolvimento de processo de fracionamento, recorrendo-se para isso ao uso de solventes estratégicos. Este passo foi desenvolvido com sucesso a partir da manipulação das solubilidades de cada um dos compostos de interesse em etanol e n-hexano. Os resultados obtidos confirmaram a possibilidade de fracionamento dos compostos alvo, pela adição ordenada dos solventes. Cerca de 39% do β-caroteno ficou dissolvido no etanol e cerca de 64% de licopeno encontrava-se dissolvido no n-hexano, indicando assim a sua separação para dois solventes distintos o que demonstra o caráter seletivo do processo desenvolvido, sem qualquer etapa prévia de otimização. Este estudo revelou que a utilização de solventes orgânicos conduz à extração seletiva de licopeno e β-caroteno, permitindo a eliminação de inúmeras etapas descritas pelos métodos convencionais. Por fim, foi possível idealizar e desenvolver um processo integrado sustentável e de relevância industrial.
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Beltran, Carbó Antoni. "Synthesis of novel molecularly imprinted polymers and their application to the solid-phase extraction of water-based matrices." Doctoral thesis, Universitat Rovira i Virgili, 2010. http://hdl.handle.net/10803/9049.
Full textAbstract:
La present tesi s'ha desenvolupat dintre de la línia de recerca que el grup té sobre el desenvolupament de nous sorbents polimèrics per a aplicar-los com a sorbents en extraccions en fase sòlida. En aquest cas, els sorbents sintetitzats són altament selectius per a la molècula d'interès i es coneixen com a sorbents d'empremta molecular.
Pel que fa al mètode de síntesi s'han explorat diferent tipus de polimeritzacions així com diferents tipus d'interacció entre els components que constitueixen el polímer a fi de millorar tant el procés de síntesi com el reconeixement de la molècula objectiu un cop obtingut el polímer per tal d'obtenir extraccions altament selectives.
Aquest sorbents s'han aplicat per a l'extracció de compostos considerats com a contaminants orgànics emergents en mostres tant d'orina humana com aigües de riu o de depuradora amb resultats satisfactoris en tots els casos, demostrant que aquest sorbents són una bona opció a l'hora de realitzar extraccions altament selectives.
The present thesis has been developed within the research trend that the group has on the development of new polymeric materials for their used as sorbents in solid-phase extraction.
In this case, the sorbents synthesised are highly selective for the molecule of interest and are known as molecularly imprinted polymers.
Regarding the synthesis of these polymers, several polymerisation protocols as well as several kinds of interactions that can be established between all the components involved in the synthesis of the polymers have been exploited.
The sorbents obtained were further applied in the selective extraction of several compounds framed within the group of emerging organic pollutants from human urine, river water or effluent water from sewage plants. In any case, a successful extraction of the target analyte was easily achieved by using any of the sorbents developed, thus proving that these sorbents are a good option when aiming to selectively extract the compound of interest from highly complex matrices.
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Pocurull, Aixalà Eva. "Extracció en fase sòlida aplicada a la determinació de compostos fenòlics." Doctoral thesis, Universitat Rovira i Virgili, 1996. http://hdl.handle.net/10803/9052.
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Xoliswa, Madlanga. "Method development and Validation for the determination of selected Polycyclic Aromatic Hydrocarbons (PAHs) in water by Solid Phase Extraction and High Performance Liquid Chromatography." Thesis, Vaal University of Technology, 2014. http://hdl.handle.net/10352/392.
Full textAbstract:
Polycyclic Aromatic Hydrocarbons (PAHs) are one of the pollutants in the environment. They are organic compounds that consist of more than one aromatic ring (Kanchanamayoon & Tatrahun 2008). Due to less information forthcoming regarding the levels of PAHs in Vaal area, this study is to evaluate the levels of PAHs in the rivers around Vaal Triangle. Three river sites such as Vaal, Barrage and Klip Rivers were selected to investigate the concentration of polycyclic aromatic hydrocarbons in water. Validation of an analytical method is the process by which it is established by laboratory studies, that the performance characteristics of the method meet the requirements for the intended analytical application. (Stockl et al 2009). The validation parameters tested were, linearity detection limit of quantitation, sensitivity, accuracy, specificity, selectivity, robustness and ruggedness.
PAHs can be determined using High Performance Liquid Chromatography (HPLC) which is a technique for separation, identification and quantification of components in a mixture. The following ten compounds were identified and quantified with a HPLC: naphthalene, acenaphthylene, phenanthrene, anthracene, fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h) anthracene and indeno(1,2,3-cd)pyrene. The linear calibration ranges from 0.1-5ppm.The linearity ranges between 0.9993-0.9999.Three reversed sorbent phases (Strata-X, MFC18 and C18) were tested for PAH retention efficiency. An optimised reverse solid phase extraction (SPE) method was used after conditioning the sorbent to extract and collect compounds of polycyclic aromatic hydrocarbons (PAHs) in river water samples. LC18 sorbent showed good recoveries after extracting PAHs standard mixture of 1 mg/l. The best performing eluting solvent was acetonitrile and very good percentage recoveries that ranged from 70% to over 100 % were obtained for eight compounds. Poor recoveries were also obtained for phenanthrene (61%) and benzo(b)fluoranthene (48%). The standard deviation ranged from 0.01 to 0.05 and the detection limits ranging from 0.01 – 0.17 mg/l were obtained. Average concentration ranges of PAHs identified within the study area were: phenanthrene (0.02 – 0.42 mg/l); anthracene (0.37 – 0.39 mg/l), fluoranthene (0.11 – 0.15 mg/l); benzo(b)fluoranthene (0.09 mg/l) and indeno(1,2,3-cd)pyrene (0.26 mg/l). However, naphthalene, acenaphthylene, benzo(k)fluoranthene, benzo(a)pyrene and dibenzo(a,h)anthracene were not detected.
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Silva, Ana Filipa Martins Cláudio da. "Extraction of added-value products from biomass using ionic liquids." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14174.
Full textAbstract:
Doutoramento em Engenharia QuímicaThe main purpose of this thesis is to investigate the potential of ionic liquids (ILs) as a new class of extractive solvents for added-value products from biomass. These include phenolic compounds (vanillin, gallic, syringic and vanillic acids), alkaloids (caffeine) and aminoacids (L-tryptophan). The interest on these natural compounds relies on the wide variety of relevant properties shown by those families and further application in the food, cosmetic and pharmaceutical industries. Aiming at developping more benign and effective extraction/purification techniques than those used, a comprehensive study was conducted using aqueous biphasic systems (ABS) composed of ILs and inorganic/organic salts. In addition, ILs were characterized by a polarity scale, using solvatochromic probes, aiming at providing prior indications on the ILs affinity for particular added-value products. Solid-liquid (S-L) extractions from biomass and using aqueous solution of ILs were also investigated. In particular, and applying and experimental factorial design to optimize the operational conditions, caffeine was extracted from guaraná seeds and spent coffee. With both types of extractions it was found that it is possible to recover the high-value compounds and to recycle the IL and salt solutions. Finally, aiming at exploring the recovery of added-value compounds from biomass using a simpler and more suistainable technique, the solubility of gallic acid, vanillin and caffeine was studied in aqueous solutions of several ILs and common salts. With the gathered results it was possible to demonstrate that ILs act as hydrotropes and that water can be used as an adequate antisolvent. This thesis describes the use of ILs towards the development of more effective and sustainable processes.
O principal objetivo desta tese recai sobre a utilização de líquidos iónicos (LIs) como uma nova classe de solventes para a extração de compostos de valor acrescentado a partir da biomassa. Nestes compostos estão incluídos os compostos fenólicos (vanilina e ácidos gálico, siríngico e vanílico), alcaloides (cafeína) e aminoácidos (L-triptofano). O interesse da extração destes compostos naturais está relacionado com as suas excelentes propriedades e consequente interesse para aplicação nas indústrias alimentar, de cosmética e farmacêutica. De forma a desenvolver uma técnica de extração/purificação mais benigna e eficiente do que as habitualmente utilizadas, foram estudados vários sistemas aquosos bifásicos (SABs) constituídos por LIs e sais orgânicos/inorgânicos. Foi também criada uma escala de polaridades para os LIs, através da determinação de parâmetros solvatocrómicos, para se poder avaliar a afinidade de diferentes LIs para compostos de valor acrescentado. Para além do uso de SABs, realizaram-se extrações do tipo sólido-líquido a partir de biomassa e utilizando soluções aquosas de LIs. Neste contexto, otimizou-se a extração da cafeína, quer de sementes de guaraná quer de borras de café, utilizando um planeamento fatorial para o efeito. Mostrou-se ainda que em ambos os tipos de extrações estudados é possível recuperar os compostos de valor acrescentado e reciclar as soluções de LI e sal utilizadas durante o processo extrativo. Por fim, com o propósito de explorar a recuperação dos compostos de valor acrescentado utilizando técnicas mais simples e sustentáveis, foram determinadas as solubilidades do ácido gálico, vanilina e cafeína em diversas soluções aquosas de LIs e sais. Foi possível demonstrar que os LIs atuam como hidrótropos e, deste modo, pode-se utilizar água como um anti-solvente adequado. Esta tese descreve a aplicação de LIs no desenvolvimento de processos extrativos mais eficientes e sustentáveis.
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Yavuz, Merve. "Investigation Of Occurrence And Fate Of Biocides In Wastewater Treatment Plants And Surface Waters." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615634/index.pdf.
Full textAbstract:
Biocides are widely used as a preservative or as an antiseptic agent in consumer care products such as
toothpaste, mouthwash, and soaps, as well as in household cleaners and even in textiles due to their
high antimicrobial effectiveness. The usage of this compounds results in discharge to wastewater
treatment plants and so into surface waters.
Their existence in the environment is of importance due to their negative effects on aquatic
environment microorganisms and human health in terms of occurrence in surface waters and their fate
in wastewater treatment plants.
In this scope, this study focuses on occurrence and fate of selected biocides, namely triclosan (TCS)
and chlorhexidine (CHD), in wastewater treatment plants and in surface waters. It was aimed to
determine the biocides levels in surface water and wastewater in Turkey. For the wastewater treatment
plant (WWTP) studies, several WWTPs with different process configurations, namely, Tatlar WWTP,
METU WWTP, Kayseri WWTP and Antalya WWTPs were selected. Composite wastewater samples
were taken from various points along the WWTPs on a seasonally basis for one year period. For the
surface water part, samples were taken monthly from three different sources with different pollution
levels, namely, Kesikköprü
Reservoir, Ç
amlidere Reservoir and Eymir Lake for one year period. All water samples were analyzed for their biocide level using liquid chromatography, following solid phase cartridge extraction. As a result of analyses, TCS concentration in surface water samples was detected as in the range of 0.65-11.15 ng/L, 0.86-48.96 ng/L and 0.86-757.7 ng/L for clean, moderately polluted and polluted water sources respectively. The recovery of solid phase extraction analyses for TCS was achieved as %92. CHD concentration was determined as in the range of <
1.33-5.31 ng/L for surface water samples and the recovery of extraction were calculated as %96 for CHD. The concentration of TCS in wastewater samples was measured as in the range of 1.77-94.47 ng/L and 1.40-15.09 ng/L for influent and effluent samples respectively. These ranges became 1.39-10.45 ng/L and <
1.32-2.44 ng/L for CHD. The highest concentrations of biocides were observed in sludge samples with concentrations of 1117-3687 &mu
g/kg and 510-2742 &mu
g/kg for TCS and CHD. Biocide removal efficiency of primary and biological treatment together was reported as % 67.5±
8.2 in January 2012 Tatlar WWTP analyses.
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Hroncová, Michala. "Studium dostupnosti antibiotik v půdě." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-432994.
Full textAbstract:
The diploma thesis is focused on the determination of tetracyclines, sulfonamides and fluoroquinolones from soil. Antibiotics such as tetracycline, chlortetracycline, oxytetracycline. ciprofloxacin, trimethoprim, sulfamethaxazole and sulfadiazin were selected due to frequent use in veterinary medicine. Due to the fact that the soil is a complex matrix and contains many components that can interfere with the detection signal of analytes, it was necessary to use the MAX column in the SPE method, which removes fulvic aned humic acid from analytes and the HLB column Final analysis of the analytes was performed by liquid chromatography with mass detesction (LC-MS). The method was also used for real soil samples, which were delivered from ÚKZUS.
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Jentzer, Jean-Baptiste. "Etude d'un procédé d'extraction en continu des glycosides de stéviol à partir des feuilles de Stévia (Stevia rebaudiana Bertoni)." Thesis, Toulouse, INPT, 2015. http://www.theses.fr/2015INPT0115.
Full textAbstract:
L’alimentation des pays industrialisés, souvent trop riche en glucides et en lipides, a engendré une augmentation marquée de l’obésité et favorisé le risque de diabète. Face à ce constat, l’industrie agroalimentaire s’est efforcée de développer des produits allégés. Au sucre, ont ainsi été substitués les édulcorants acaloriques, molécules au goût sucré non métabolisées par le corps humain. Ces édulcorants sont souvent obtenus par voie de synthèse chimique comme l’aspartame, l’acésulfame K ou encore le sucralose. S’ils sont autorisés dans la confection de produits alimentaires, la toxicité de ces édulcorants et leur impact sur la santé humaine nourrissent cependant les débats au sein de la communauté scientifique, ainsi des solutions alternatives sont envisagées. Stevia rebaudiana Bertoni est une plante originaire du Paraguay. Son intérêt principal réside dans le fait qu’elle contient des molécules acaloriques au goût sucré, les glycosides de stéviol, dont les plus connus sont le rébaudioside A et le stévioside. Les études effectuées sur ces diterpènes glycosilés tendent à souligner leur innocuité. Ils présenteraient même des vertus thérapeutiques, comme des propriétés anti-hypertensive ou antidiabétique, et semblent ainsi être une alternative prometteuse au sucre et aux édulcorants artificiels. Notre étude s’est orientée sur l’extraction aqueuse des glycosides de stéviol des feuilles de Stévia. A l’échelle laboratoire, nous avons pu mettre en évidence que la cinétique d’extraction des molécules cibles est principalement limitée par la diffusion des solutés dans la matrice solide végétale. Il n’y aurait pas de réaction chimique, de gonflement de la matière ou de modification de la porosité pendant le processus d’extraction. Nous avons également pu souligner que la préparation de la matière (séchage et broyage) et les conditions opératoires (température, ratio liquide-solide et agitation) sont des facteurs prépondérants sur l’efficacité d’extraction des édulcorants. A l’échelle pilote, les résultats obtenus en systèmes discontinu et continu ont pu mettre en exergue des influences similaires de la préparation de la matière et des conditions opératoires ; nous avons de plus pu démontrer que la qualité du mélange des phases solide et liquide était un facteur clé à l’efficacité de l’extraction. Fort de ces résultats nous avons pu développer un procédé d’extraction en système continu, adapté à l’extraction des glycosides de stéviol des feuilles de Stévia, et combiné à une étape de séparation solide-liquide. Au travers de nos différentes expériences, nous avons pu décrire précisément son fonctionnement et optimiser l’extraction afin de pouvoir envisager une transposition à l’échelle industrielleIndustrialized countries food, often too rich in carbohydrates and fat, has resulted in an important increase in obesity and risk of diabetes. Given this fact, the food industry tries to develop diet products. Sugar was substituted by calorie-free sweeteners, sweet-tasting molecules non-metabolized by the human body. These sweeteners are often obtained by chemical synthesis such as aspartame, acesulfame K or sucralose. Even if they are allowed in the manufacture of food products, the toxicity of these sweeteners and their impact on human health raise debate within the scientific community, so alternatives are being considered. Stevia rebaudiana Bertoni is a plant native from Paraguay. Its main interest lies in the fact that it contains calorie-free sweet tasting molecules, steviol glycosides, of which the most common are rebaudioside A and stevioside. Studies of these glycosylated diterpenes tend to highlight its safety. They even present therapeutic characteristics, such as anti-hypertensive or anti-diabetic properties, and thus seem to be a promising alternative to sugar and artificial sweeteners. Our study focused on the aqueous extraction of steviol glycosides from Stevia leaves. At thelaboratory scale, we were able to demonstrate that extraction kinetics of target molecules are mainly limited by diffusion of solutes in the plant solid matrix. There would be no chemical reaction, swelling of the plant material, or modification of the porosity during the extraction process. We have also shown that the preparation of the plant material (drying and milling) and the operating conditions (temperature, liquid-solid ratio and agitation) are overriding factors on the sweeteners’ extraction efficiency. At the pilot scale, the results obtained in batch and continuous systems could highlight similar influences with the preparation of the plant material and the operating conditions. We have also shown that the quality of the mixing of solid and liquid phase was a key factor in extraction efficiency. With these results we have developed a continuous extraction process, suitable for the extraction of steviol glycosides from Stevia leaves, which has combined with a step of solid-liquid separation. Through our experimentation we have accurately described its operation and optimized the extraction in order to consider a transposition to the industrial scale
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Bratkowska, Dominika. "Development and application of new polymeric materials for sorptive extraction techniques." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/63173.
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El desenvolupament de diferents materials per a les tècniques d’extracció mitjançant processos de sorció és una àrea en continua expansió; no obstant, l’extracció d’anàlits polars encara és un tema que requereix més investigació. En aquesta Tesi s’han desenvolupa nous materials que reuneixen de selectivitat i/o capacitat característiques per a extreure contaminants orgànics polars en mostres aquoses. La primera part descriu el desenvolupament de nous materials polimèrics que milloren la capacitat i selectivitat de l’extracció en fase solida, i hi inclau els polímers altament entrecreuats amb caràcter hidrofílic, els sorbents altament entrecreuats d’intercanvi iònic de mode-mixte i els líquids iònics suportots en fases polimèriques; així com la seva avaluació com a nous sorbents per a la extracció de contaminats polars en diferents mostres aquoses mediambientals seguit de l’anàlisi per LC. La segona part está centrada en la preparació de noves barres agitadores amb recobriments monolítics polars i la seva posterior aplicació per l’extracció d’analits polars en diferents aigües de procedéncia mediambiental.The development of different materials for sorptive extraction techniques is a continuously evolving field of research. Although there have been significant developments in this area, the extraction of polar analytes is still considered the bottleneck of the extraction process. The efforts have been undertaken to improve capacity and selectivity. For this reason, one of the main objectives of this Thesis is to develop new materials to extract polar organic contaminants from water samples. The first part reports on the development of new polymeric materials for solid-phase extraction including hypercrosslinked polymers with hydrophilic character, mixed-mode ion-exchange hypercrosslinked sorbents and supported ionic liquid polymeric phases and their evaluation as SPE sorbents for the extraction of polar contaminants, followed by LC analysis. The second part is focused on the preparation of new stir bars with polar monolithic coatings and their application to stir bar sorptive extract polar analytes from environmental water samples.
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Arrambide, Cruz Carlos. "Méthodologies de synthèse de résines formo-phénoliques chélatantes : vers une extraction solide-liquide optimisée des métaux stratégiques." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT169.
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L’extraction d’éléments d’intérêt (terres rares, métaux lourds, métaux de transition, radionucléides) de de minerais conventionnels ou non conventionnels (mines urbaines) et d’effluents industriel ou nucléaire est un enjeu majeure dans les procédés d’extraction, de recyclage et/ou de décontamination.Un grand nombre de solides organiques et inorganiques, chélatants ou échangeurs d’ions, ont été développés pour un tri ionique sélectif par procédé solide/liquide.L’introduction covalente de ligands spécifiques dans le squelette de la résine permet d’augmenter la sélectivité vis-à-vis d’une cible métallique par la nature des agents de complexation, leurs sites de chélation et leur rigidité.L’objectif de cette thèse recouvre d’une part la synthèse de systèmes chélatant réactifs, leur polymérisation pour la préparation des résines « super »chélatantes et d’autre part, l’évaluation des polymères pour l’extraction/séparation d’ions, les terres rares étant plus particulièrement ciblées.A partir de résines formo-phénolique incorporant du catéchol et la 8-hydroxyquinoléine qui sont des précurseurs phénoliques, nous avons pu montrer que la récupération sélective du germanium été possible vis-à-vis du silicium ou du zinc en fonction de leur proportion dans la matrice polymérique.La synthèse des précurseurs phénoliques intégrant des ligands comme l’acide diglycolamique et les diglycolamides a permis la mise en œuvre de résine pour la récupération des terres rares. Une étude sur la compréhension de la synthèse des résines ainsi que leurs performances d’extraction a ainsi été réalisée et a pu mettre en évidence le potentiel de ces résines pour la récupération et valorisation des terres rares.Une ouverture vers d’autres possibilités de synthèses de ce type de résines (matériaux poreux, sous forme de mousse…) est également proposée pour permettre d’augmenter les surfaces de contacts lors des extractions solide-liquide et ainsi augmenter les performances de ces matériauxExtraction of specific targeted species (rare earth, heavy metals, transition metals, radionuclides) from industrial (mining deposit and urban mining) and nuclear effluents is an important issue in the recycling and / or decontamination processes. A large number of organic and inorganic solids, chelating or ion-exchanging materials, have been developed for selective ionic separation by solid / liquid process. Metal-specific ligands incorporate in the structure of the resin itself is an interesting way to perform ion separation taking the advantage of the selectivity of chelating agents. The aims of this project are firstly the synthesis of chelating original systems and then prepare specific ion exchange resins.From formo-phenolic resins incorporating catechol and 8-hydroxyquinoline, we have been able to show that the selective recovery of germanium from silicon or zinc was possible, , depending on their proportion of each phenolic precursors in the polymeric matrix.The synthesis of the phenolic precursors integrating ligands such as diglycolamic acid and diglycolamides allowed the use of resin for the recovery of rare earths elemnets. A study on the understanding of the synthesis of resins as well as their performance of extraction was thus realized and was able to highlight the potential of these resins for the recovery and valorization of the rare earths elements.An opening towards other possibilities of synthesis of this type of resins (porous materials, in the form of foam, etc.) is also proposed in order to increase the contact surfaces during solid-liquid extractions and thus increase the performance of these materials
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Capellini, Maria Carolina. "Extração de óleo de farelo de arroz utilizando solventes alcoólicos: avaliação de alterações na fração proteica e na composição do óleo." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/74/74132/tde-23052013-134459/.
Full textAbstract:
Um dos principais setores do sistema agroindustrial brasileiro é composto pelo processamento de oleaginosas. Sua importância não se deve apenas ao seu produto principal, o óleo, mas também à fração desengordurada, composta por proteínas. Tradicionalmente, hexano é o solvente empregado na extração de óleos vegetais e, por esta razão, os objetivos principais deste trabalho foram estudar a viabilidade de substituição deste solvente por solventes alcoólicos na extração do óleo de farelo de arroz e, neste sentido, avaliar o impacto desta mudança nas características do óleo e da fração proteica. Foram realizados experimentos de extração sólido-líquido na condição de equilíbrio com a finalidade de avaliar a influência das variáveis de processo, tipo de solvente (etanol ou isopropanol), teor de água no solvente (0, 6 ou 12%) e temperatura (50 a 80 °C), na extração do óleo de farelo de arroz. Através dos experimentos de extração foi possível caracterizar os extratos obtidos e o farelo desengordurado em termos de rendimento de extração de compostos lipídicos, proteicos e minoritários, além da caracterização da fração proteica presente no rafinado, em termos de solubilidade e análise térmica. De maneira geral, os resultados mostraram influência da água no solvente no sentido da supressão da extração de óleo e, por outro lado, observou-se que o aumento da temperatura favoreceu o processo de extração lipídica. No caso do conteúdo proteico presente no extrato, observou-se que a hidratação do solvente e a temperatura favoreceram a extração de proteínas. A elevação da temperatura de processo favoreceu também, a extração de γ-orizanol, porém o aumento da água no solvente diminuiu a extração deste composto minoritário. A água também exerceu forte influência na quantidade de acilgliceróis e ácidos graxos livres transferidos para o extrato, porém, para o teor de fosfolipídeos, essa influência foi menor. As condições de processo não afetaram significativamente a composição do óleo, que se mostrou típica de óleo de farelo de arroz. Com relação à fração proteica, a solubilidade e propriedades térmicas, que definem o grau de desnaturação proteica, sofreram forte influência do grau de hidratação do solvente e da temperatura de processo, uma vez que à medida que a quantidade de água no solvente e a temperatura foram aumentados, notou-se uma diminuição no índice de solubilidade de nitrogênio. A partir dos resultados obtidos pode-se inferir que a extração de óleo de farelo de arroz com solventes alternativos, etanol e isopropanol, é possível, porém, as condições de processo devem ser muito bem avaliadas de maneira que este seja viável e os produtos oriundos, tanto o óleo de farelo de arroz quanto a fração proteica, possuam qualidade adequada para serem destinados à fins alimentícios.One of the main areas of the Brazilian agroindustrial system is composed by the processing of oilseeds. Its importance is not only due to its main product, the oil, but also to the defatted fraction, composed of proteins. The hexane is the solvent traditionally used in vegetable oils extraction and, for that matter, the main objectives of this paper were to study the feasibility of substitution of t his solvent for alcoholic solvents on the rice bran oil extraction and also evaluate the impact of this change on the oil characteristics and the protein fraction. Some solid-liquid extraction experiments on balance condition were made to evaluate the variables on the process, such as the solvent type (ethanol or isopropanol), solvent water content (0, 6 or 12%) and temperature (50 to 80 °C) in the rice bran oil extraction. This way, the results show water influence on the solvent suppressing the oil extraction, and, on the other hand, the temperature increase benefits the process. Through extraction experiments, it was possible to characterize the obtained extracts and the defatted bran in terms of lipid, protein and minorities compound extraction, besides the characterization of the protein fraction present on the raffinated in terms of solubility and thermal analysis. In general, the results showed the water solvent influence in order to suppress the oil extraction and, on the other hand, it has been observed that the temperature increase benefited the lipid extraction process. Related to the protein content present in the extract, it was observed that the solvent hydration and temperature benefited the protein extraction. The temperature increase on the process also benefited the the γ-oryzanol extraction, however, the water solvent increase decreased the extraction of this minority compound. The water also has a strong influence on the amount of acylglycerol and free fatty acid transferred to the extract, however, for the phospholipids content, there is a decreasing influence. The process conditions did not have a significant affection on the oil composition, which is typical on rice bran oil. Regarding the protein fraction, solubility and thermal properties, which define the protein denaturing degree, there was a strong influence of the solvent hydration degree and the processing temperature, once the amount of water in the solvent and temperature are increased, it was noticed the decrease on the nitrogen solubility index. Based on the results it is possible to infer that the rice bran oil extraction with alternative solvents, ethanol and isopropanol, is possible, however, the process conditions must be well evaluated in order to be viable and the originated products, as well the rice bran oil as the protein fraction, have the proper quality for food purposes.
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Mendez, Lina Maria Rayo. "Isolamento de polissacarídeos não amiláceos da banana (musa cavendishii L. variedade Nanicão) e seu potencial uso como ingrediente funcional." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-03102018-101135/.
Full textAbstract:
Neste trabalho, polissacarídeos não amiláceos (PNAs) da banana madura com potencial de propriedades imunomoduladoras foram obtidos por meio da remoção dos açúcares solúveis (glicose, frutose e sacarose) do purê de banana submetido a duas técnicas de extração: sólido-líquido (ESL) com agitação mecânica e assistida por ultrassom (EAU) usando etanol a 99,5 g/100 g como solvente. Para o estudo em batelada, diferentes razões da matéria-prima/solvente (1:5, 1:7 e 1:10) g/mL, tempos de extração (30, 60 e 90) min e duas temperaturas de (25 e 65) °C foram estudados. No estudo cinético, o impacto da redução da razão matéria-prima/solvente de 1:5 para 1:3 g/mL foi estudado até 90 min, nas mesmas condições estudadas na extração em batelada. O teor de açúcares solúveis (AS) medido nos extratos foi superior na temperatura de 65°C, porém às razões de 1:7 e 1:10, não resultou em maior quantidade de AS nos extratos, portanto, menores quantidades de etanol podem ser usadas diminuindo custos. Com o emprego da técnica EAU à 25 °C e tempo de extração de 30 min, foi observado que uma redução da razão matéria-prima/solvente até 1:3 g/mL produz maior rendimento de processo. No entanto, foi observado que maiores tempos de extração promoveram degradação da parede celular da matéria-prima. Entre os modelos cinéticos testados, o ajuste do modelo de Patricelli aos dados experimentais indicou que a ESL é regida pela fase de lavagem em que ocorreu 85 % da extração dos AS. Frações molares de glicose, ácidos galacturônicos, manose, arabinose, xilose, galactose de conteúdo monossacarídeo foram observadas nos rafinados, indicando possivelmente serem parte de polissacarídeos do tipo ?-glicanos, xilomananos glucomananos, arabinogalactanos e arabinoxilanos.In this work, non-starch polysaccharides (PNAs) of ripe bananas with potential for immunomodulatory properties were obtained by means removing the soluble sugars (glucose, fructose and sucrose) from banana puree submitted to two extraction techniques: solid-liquid (SLE) with mechanical stirring and ultrasonic assisted (UAE) using 99.5 g/ 100 g ethanol as solvent. For the batch study, different ratios of the raw material/ solvent (1:5, 1:7 and 1:10) g/ mL, extraction times of (30, 60 and 90) min and two temperatures of (25 and 65 ) °C were studied. In the kinetic study, the impact of reducing the raw material/ solvent ratio from 1:5 to 1:3 g/ mL was studied up to 90 min, under the same conditions studied in batch extraction. The soluble sugar content (AS) measured in the extracts was higher at temperature of 65 °C, however, at the ratios of 1:7 and 1:10, did not result in higher amount of AS in the extracts, therefore, smaller amounts of ethanol can be costs. With the use of the UAE technique at 25 °C and extraction time of 30 min, it was observed that a reduction of the raw material / solvent ratio up to 1:3 g / mL produces a higher process yield. However, it was observed that longer extraction times promoted degradation of the cell wall of the raw material. Among the kinetic models tested, the adjustment of Patricelli model to the experimental data indicated that the SLE the predominance is by the washing phase in which 85% of the AS extractions occurred. Glucose molar fractions, galacturonic acids, mannose, arabinose, xylose, galactose of monosaccharide content were observed in the raffinates, indicating possibly being part of polysaccharides as ?-glycan, xylomannans, glucomannans, arabinogalactans and arabinoxylans.
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Gaubaitė, Giedrė. "Buspirono ir fluoksetino ekstrakcijos iš kraujo plazmos tinkamiausių sąlygų nustatymas, medžiagų koncentraciją įvertinant efektyviosios skysčių chromatografijos metodu." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140618_220002-28969.
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Tyrimo objektas – kraujo plazma su vaistinių medžiagų mišiniu (buspirono hidrochloridu ir fluoksetino hidrochloridu). Šio tyrimo tikslas – nustatyti tinkamiausias ekstrakcijos sąlygas, reikalingas vaistų mišinio (buspirono ir fluoksetino) išskyrimui iš kraujo plazmos bei pritaikyti efektyviosios skysčių chromatografijos metodiką vaistų mišinio veikliųjų junginių identifikavimui ir kiekio nustatymui. Darbo uždaviniai buvo pritaikyti ir validuoti efektyviosios skysčių chromatografijos metodiką; išskirti buspirono ir fluoksetino vaistų mišinį iš kraujo plazmos skysčių – skysčių (SSE) ir kietafazės ekstrakcijos (KFE) metodais; optimizuoti geriausią ekstrakcijos metodą.
Tyrimo metu buvo pritaikyta ESC metodika buspirono ir fluoksetino identifikavimui ir kiekio nustatymui. Atlikta ESC metodikos validacija: įrodytas specifiškumas, rezultatų glaudumas, remiantis koreliacijos koeficientu (R2) įvertintas metodikos teisiškumas, buspirono ir fluoksetino koreliacijos koeficientai atitinkamai lygūs 0,9997 ir 0,9998. Nustatytos aptikimo ribos (buspironui 0,4 µg/ml, fluoksetinui 0,75 µg/ml) ir nustatymo ribos (buspironui 0,75 µg/ml, fluoksetinui 1 µg/ml). Vaistinių medžiagų mišinys išskirtas iš kraujo plazmos SSE ir KFE metodais. Nustatyta, kad KFE yra greitesnis ir tikslesnis metodas lyginant su SSE, todėl KFE pasirinkta tolesniam metodo optimizavimui. Eksperimentai atlikti su 6 organiniais tirpikliais (metanoliu, etanoliu, propanoliu, trichlormetanu, dichlormetanu ir acetonitrilu)... [toliau žr. visą tekstą]The object of study – human plasma with the mix of two drugs (buspirone hydrochloride and fluoxetine hydrochloride). The aim of this study was to determine extraction conditions for buspirone and fluoxetine isolation from human plasma and to apply high-performance liquid chromatography (HPLC) method for quantitative analysis of the drugs after extraction. The objective was to apply and validate HPLC procedure; to extract buspirone and fluoxetine from human plasma by liquid-liquid extraction (LLE) and solid phase extraction (SPE); to optimize efectiveness extraction method. The HPLC method for identification and quantitative analysis of drugs was optimized. The mobile phase was 0,1 per cent of trifluoroacetic acid and acetonitrile.Validation of the HPLC method was carried out. The specificity, precision, linearity, limits of detection (buspirone 0,4 µg/ml, fluoxetine 0,75 µg/ml) and quantification (buspirone 0,75 µg/ml, fluoxetine 1 µg/ml) were determined. Validate HPLC method was applied for analysis of buspirone and fluoxetine after extraction. Drugs were extracted from human plasma by LLE and SPE methods. The best recovery of analites gave SPE methods. The recoveries of the drugs using six different organic solvents (methanol, propanol, ethanol, trichloromethane, dichloromethane, acetonitrile) were examined. Selected the most appropriate environment (acidify) for methanol and the methanol percentage of the elution solvent (80 per cent). Selected two of the most appropriate... [to full text]
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Silvas, Flávia Paulucci Cianga. "Utilização de hidrometalurgia e biohidrometalurgia para reciclagem de placas de circuito impresso." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-28082015-114810/.
Full textAbstract:
A geração global de resíduo eletrônico (REEE) cresce a uma taxa de cerca de 40 milhões de toneladas por ano. Este constante incremento na geração dos REEEs somado às recentes legislações tem impulsionado pesquisas focadas no desenvolvimento de processos para recuperação de materiais e sustentabilidade da indústria eletroeletrônica. Dentro destes resíduos encontram-se as placas de circuito impresso (PCIs) que estão presentes na maioria dos EEEs, têm composição heterogênea que varia conforme a fonte, país de proveniência e época, e tecnologia de fabricação. Assim, este trabalho teve por objetivo a realização de rota hidrometalúrgica (extração sólido/líquido) e biohidrometalúrgica para reciclagem de placas de circuito impresso provenientes de impressoras visando a recuperação de cobre. Para tanto fez-se inicialmente a caracterização da PCI e o desenvolvimento de uma rota combinada de processamento físico seguida por processo hidrometalúrgico ou biohidrometalúrgico. O processamento físico e de caracterização foi composto por etapas de cominuição, separação magnética, classificação granulométrica, visualização em lupa binocular, microscópio eletrônico de varredura acoplado com detector de energia dispersiva de raios X (MEV/EDS), digestão ácida, perda ao fogo e análise química por AAS e ICP. Já, o processamento hidrometalúrgico foi composto por duas etapas de extração sólido/líquido: a primeira em meio sulfúrico e a segunda em meio sulfúrico oxidante. Para os ensaios de biolixiviação utilizou-se uma cepa bacteriana composta por 3 espécies microbianas: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans e Leptospirillum ferrooxidans. Verificou-se que a placa possui 4 camadas de Cu intercaladas por fibra de vidro, é lead free e seus componentes representam 53,3 % do seu peso. A porcentagem em massa correspondente ao material não magnético é de 74,6 % e do magnético 25,4 %. Os materiais moído e não magnético apresentaram tendência em se acumular nas frações mais grossas. Já na fração magnética, o acúmulo do material ocorreu na fração mais fina (0,053 mm). A separação dos metais através de classificação granulométrica não foi possível. A PCI estudada é composta por: 44% de metais, 28,5 % de polímeros e 27,5 % de cerâmicas. Sendo: Ag-0,31 %; Al3,73 %; Au0,004 %; Cu 32,5 %; Fe1,42 %; Ni0,34 %; Sn0,96 % e Zn0,64 %. A extração de Cu no processamento hidrometalúrgico foi de 100 % e o fator de recuperação 98,46 %, o que corresponde a uma recuperação de 32 kg de Cu em 100 kg de PCI. Já no processamento biohidrometalúrgico, a extração de Cu alcança 100 % quando utilizados 2 % de densidade de polpa e 100 % de inóculo. O fator de recuperação é de 100 % e a recuperação de Cu em 100 kg de PCI é de 32,5 kg. O processamento hidrometalúrgico apresenta como vantagens quando comparado ao biohidrometalúrgico: menor tempo de extração (8 h versus 4 dias); seletividade de Cu; maior densidade de polpa (10 % versus 2 %). Já a biolixiviação utiliza menor temperatura de trabalho (36 ºC versus 75 ºC) e dispensa a etapa de separação magnética.The increase in the generation of waste electrical and electronic equipment (WEEE), 40 tons per year, allied with the enactment of new laws encouraged researches focused on the developing of processes to reclaim materials and on the sustainability of the electrical and electronics industry. Whithin the WEEEs, printed circuit boards (PCB) composition is heterogeneous and varies according to several factors, including: kind of EEE, when and where it was produced and fabrication technology. The goal of this work is to perfom a hydrometallurgical route (solid/liquid extraction) and a biohydrometallurgical route to recycle PCB from discarded printers aiming the recovery of copper. To do so, the first step is to characterize the PCB and the development of a combined fisical processing followed by hydrometallurgical and biohydrometallurgical routes. The fisical and the characterization processes, in that order, consisted on griding, magnetic separation, granulometric screening, visual assessement by binocular magnifier, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), acid digestion, loss on fire, and chemical analyzes by AAS and ACP-OES. The hydrometallurgical stage consisted on two steps: solid/liquid extraction by sulfuric acid leaching and solid/liquid extraction by sulfuric acid leaching with an oxidizing agent. The bioleaching tests used a mixed bacterial strain: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans. The results showed that PCB consisted on 4 layers of copper and fiber glass, not possesing lead (leadfree) on its composition and its components constitute 53.3 % weight percentage. The non-magnetic fraction (NMA) weight percentage represents 74.6 %, the magnetc fraction (MA) represents 25.4 %. The grinded material and the non-magnetic fraction presented an inclination to build up on thickest fractions. On the magnetic fraction this behavior occurred on the thinnest fraction (0.053 mm). The metal separation using granulometric screening was not possible and the visual assessement by binocular magnifier was conclusive for this research. The composition of the studied PCB is: 44 % metal, 28.5 % polymer and 27.5 % ceramics. Beeing: Ag-0.31 %, Al-3.73 %, Au-0.004 %, Cu-32.5 %, Fe-1.42 %, Ni-0.34 %, Sn-0.96 %, Zn-0.64 % and other metals-4.10 %. Copper extraction in the hydrometallurgical process achieved 100 % and the recuperation factor 98.46 %, which means a recovery of 32 kg of copper in 100 kg of PCB. However in biohydrometallurgical process, the copper extraction reached 100 % on the forth day using a 2 % pulp density and 100 % inoculum. The recuperation factor achieved 100 % and, therefore, copper recovery in 100 kg of PCB is equivalent to 32.5 kg. The hydrometallurgical processing has many advantages compared to the biohydrometallurgical processing: a smaller extraction time (8 h versus 4 days); Cu selectivity; higher pulp density (10 % versus 2 %). However, bioleaching uses an inferior working temperature (36 ºC versus 75 ºC) and dont require magnetic separation.
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Sartoratto, Adilson. "Desenvolvimentos metodologicos em microextração em fase solida acoplada a cromatografias gasosa e liquida." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250204.
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Orientador: Fabio AugustoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: O trabalho que teve como objetivo desenvolver metodologias em Microextração em Fase Sólida para utilização em cromatografia líquida e gasosa será apresentado em dois capítulos: no primeiro capítulo a análise de pesticidas organofosforados (OPP) em amostras aquosas e infusão de plantas foi realizada por cromatografia líquida de alta eficiência/detetor de arranjo de diodos (HPLC-DAD) utilizando uma interface de dessorção para SPME e uma fibra sol-gel Carbowax 20M ormosil, produzidas em nosso laboratório. Após avaliação de desempenho da interface e eficiência da fibra sol-gel, uma metodologia de análise foi desenvolvida, avaliando-se os principais parâmetros de validação: sensibilidade, linearidade, faixa linear, exatidão, precisão, limites de detecção e quantificação. No segundo capítulo, tentamos relacionar a composição química de voláteis de plantas analisados por SPME-GC-MS com a atividade antimicrobiana de óleos essenciais. A avaliação dos voláteis foi feita utilizando-se dois tipos de fibras comerciais: PDMS e PDMS/DVB e também pela análise do óleo essencial obtido por métodos tradicionais. A atividade antimicrobiana dos óleos essenciais foi realizada pelo método da concentração mínima inibitória (MIC) com a finalidade de selecionar óleos com potencial terapêutico, em substituição às drogas existentes no mercado.
Abstract: The present work is presented in two chapters that had the scope of developing methodologies for solid phase microextraction coupled to gas and liquid chromatography. The first chapter discusses analysis of organophosphorous pesticides in water soluble samples and plant infusions by High Performance Liquid Chromatography coupled to photodiode array detector (HPLC-DAD) using a SPME desorption interface and Carbowax 20M sol-gel fiber, both produced in lab. After interface and sol-gel fiber efficiency evaluation an analysis method was developed that considered validation parameters: sensibility, linearity, linear range, accuracy, precision, detection limit, and quantification limit. In the second chapter we proposed to establish a relationship among plant's chemical volatile composition analyzed by SPME-GC-MS and antimicrobial activity of essential oils. Two commercial fibers: PDMS and PDMS-DVB were employed for essential oil analysis. Essential oils with potential therapeutic properties in substitution to known commercial drugs were chosen by minimum inhibition concentration experimental model.
Doutorado
Quimica Analitica
Doutor em Ciências
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Scharlack, Nayara Kastem. "Estudo do efeito do tipo e grau de hidratação de solventes alcoólicos na extração simultânea de óleo e de ácidos clorogênicos de torta de sementes de girassol." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/74/74132/tde-13102015-163128/.
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Nos dias atuais, a preocupação com o meio ambiente vem ocupando espaço considerável nos principais centros de debates. A procura por solventes provenientes de fontes renováveis que possam substituir solventes de origem fóssil em processos industriais se faz necessária. Tradicionalmente o hexano, derivado do petróleo, é utilizado como extratante industrial de óleos de matrizes oleaginosas, no entanto, este solvente apresenta desvantagens em termos de segurança operacional devido à alta toxicidade e inflamabilidade. Neste contexto, a presente dissertação de mestrado objetivou avaliar a viabilidade técnica da substituição do hexano por solventes alcoólicos, etanol e isopropanol na extração do óleo da torta de prensagem de sementes de girassol. A influência das variáveis tipo e grau de hidratação do solvente alcoólico e temperatura foi avaliada sobre a composição em ácidos graxos, a estabilidade oxidativa do óleo extraído e o teor de ácidos clorogênicos, tocoferóis e fosfolipídeos. A matéria prima foi submetida ao processo de extração sólido-líquido em um simples estágio, utilizando os solventes em grau absoluto e hidratado, nas temperaturas de 60 a 90 °C, sendo objetivo de estudo o rendimento do óleo, o teor de proteína em base seca, índice de retenção, teor de água na fase extrato e teor de ácidos clorogênicos. Extrações sequenciais empregando três estágios na temperatura de 90 °C também foram realizadas para avaliar o teor de óleo residual, extração de ácidos clorogênicos, avaliação da estabilidade oxidativa e determinação dos teores de tocoferóis e fosfolipídeos. Em linhas gerais, pode-se inferir que a hidratação do solvente afetou de forma negativa o rendimento da extração e observou-se também que com o aumento da temperatura, aumenta-se a quantidade de material lipídico extraído. O teor de água no solvente favoreceu a extração dos ácidos clorogênicos, sendo que a temperatura não exerceu influência sobre estes resultados. Quando avaliada a extração de tocoferóis, pode-se notar que os solventes isopropanol (absoluto e hidratado) e etanol absoluto possibilitaram maior extração de α tocoferol quando comparados ao etanol azeotrópico. No entanto, os teores de tocoferóis nos óleos extraídos com álcoois foram inferiores aos detectados nos óleos obtidos com hexano. Na avaliação da estabilidade oxidativa pode-se observar que os óleos extraídos com etanol absoluto e azeotrópico apresentaram estatisticamente o mesmo tempo de indução, fato este que pode estar relacionado aos altos teores de fósforo detectados nos óleos obtidos com estes solventes etanólicos, sugerindo assim que estes solventes são capazes de extrair compostos minoritários que atribuem maior estabilidade oxidativa ao óleo.Nowadays, the concern regarding the environment has taken a considerable amount of space at the main debate centers. The search for solvents which come from renewable sources that are capable of replacing solvents that come from fossils in industrial processes is paramount. Traditionally the hexane derived from oil is used as an industrial solvent for oleaginous sources. However this solvent presents some disadvantages in terms of operational safety due to the high toxicity and inflammability. In this context, this master´s dissertation has aimed to evaluate the technical viability of the replacement of hexane for alcoholic solvents, ethanol and isopropanol in oil extraction from the meal obtained in the pressing stage of sunflower seeds. The influence of the type and level of hydration of the alcoholic solvents and temperature has been evaluated over the composition in fatty acids, the oxidative stability of the extracted oil, the level of chlorogenics acids, of tocopherols and phospholipids. The meal was submitted to the solid-liquid extraction process in one single stage, using the solvents in absolute and hydrated grade from 60 up to 90 °C, hence the purpose of this study the yield of the oil, the protein level in dry basis, mass of adhered solution (retention index), water level in the extract phase and the chlorogenic acids content. Consecutive extractions applying three stages at 90 ºC have also been performed to evaluate the residual oil content, chlorogenic acids yield, evaluation of oxidative stability and the contents of tocopherols and phospholipids. In summary, it can be concluded that the solvent hydration has affected in a negative fashion the performance of the extraction and it was also noticed that, with the rising in temperature, the amount of lipid extract was increased. The level of water in the solvent has favored the extraction of chlorogenic acids since the temperature has not affected the results. Once the tocopherol extractions are analyzed, it is possible to verify that the isopropanol solvents (absolute and hydrated) and absolute ethanol have enabled a larger extraction of α tocopherol when compared to azeotropic ethanol. However, the levels of tocopherol extracted from alcohols were less than the ones obtained from hexane. In the oxidative stability evaluation it was possible to observe that the oils extracted from absolute and azeotropic ethanol have presented statistically the same induction time, a fact which can be related to high levels of phosphorus detected in the oils obtained from ethanol solvents which suggest that such solvents are capable of extracting minor compounds that attribute more oxidative stability to the oil.
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Vasconcelos, Géssica Adriana. "Estendendo a caracterização dos compostos nitrogenados em resíduo de vácuo por FT-ICR MS." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/5952.
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Outro
Petroleomics by FT-ICR MS was able to characterize petroleum and its derivatives at molecular level. The most used ionization source on the analysis of these compounds is electrospray. However, species that are more basic or more acidic suppress the ionization of other compounds with less strength. This disadvantage consists of, especially in positive mode, only detecting compounds with higher pKa values preventing the mass spectrometer from reading less basic species that is also present in the sample. In view of this, the development of new methods whose purpose is to minimize these effects is essential. An alternative is to use fast techniques of extraction and separation followed by analysis by FT-ICR MS. This study pursued two goals: first, to perform an extraction of vacuum residue into basic and neutral nitrogen compounds using different methods, and second, to fractionate the basic nitrogen compounds present in RV according to their mass/ratio. Three methods were tested to achieve the first objective: solvent extraction (LLE), column chromatography (LC), and solid phase extraction (SPE). The results showed that LLE was the less selective technique among all three studied procedures. SPE and LC showed similar results, and they allowed to partially separate the basic nitrogen compounds from neutral species. To accomplish the second goal, a fractionation using SPE was applied to the vacuum residue sample. This procedure permitted to detect compounds that apparently were not present in the untreated sample as a consequence of a reduction on ion suppression effect. Electrospray ionization and high resolution mass spectrometry (FT-ICR MS) were employed on the analysis of each sample.
A petroleômica por FT-ICR MS foi capaz de caracterizar o petróleo e seus diferentes derivados a nível molecular. A fonte de ionização mais utilizada na análise destes compostos é o electrospray. Componentes mais básicos e mais ácidos, entretanto, suprimem a ionização de outras espécies com menor força. A grande desvantagem deste fato consiste, especialmente no modo positivo, detectar somente os compostos com elevado pKa impedindo a leitura das espécies menos básicas presentes na mesma amostra. À vista disso, é fundamental o desenvolvimento de novos métodos que tenham por finalidade minimizar estes efeitos. Uma alternativa é fazer o uso de técnicas rápidas de extração e separação seguida pelas análises por FT- ICR MS. Desta forma, este estudo teve dois objetivos principais: primeiro, realizar uma extração dos compostos nitrogenados de resíduo de vácuo em suas frações básica e neutra utilizando diferentes métodos e, segundo realizar um fracionamento dos compostos nitrogenados básicos presentes em RV de acordo com a sua massa. Para se alcançar o primeiro objetivo, três métodos foram testados: Extração líquido-líquido (LLE), cromatografia em coluna clássica (LC) e extração em fase sólida (SPE). Os resultados mostraram que o LLE foi a menos seletiva dentre os três procedimentos estudados. SPE e LC apresentaram resultados semelhantes e foi possível separar parcialmente os compostos básicos das espécies neutras. Para alcançar o segundo objetivo, um fracionamento utilizando extração em fase sólida foi empregado na amostra de resíduo de vácuo. Este procedimento permitiu detectar compostos que aparentemente não estavam presentes na amostra não tratada como consequência da redução do efeito de supressão iônica. A ionização por electrospray e por espectrometria de massa de alta resolução (FT-ICR MS) foram utilizados na análise de cada amostra.
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Anumol, Tarun, Sylvain Merel, Bradley Clarke, and Shane Snyder. "Ultra high performance liquid chromatography tandem mass spectrometry for rapid analysis of trace organic contaminants in water." Chemistry Central, 2013. http://hdl.handle.net/10150/610118.
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BACKGROUND:The widespread utilization of organic compounds in modern society and their dispersion through wastewater have resulted in extensive contamination of source and drinking waters. The vast majority of these compounds are not regulated in wastewater outfalls or in drinking water while trace amounts of certain compounds can impact aquatic wildlife. Hence it is prudent to monitor these contaminants in water sources until sufficient toxicological data relevant to humans becomes available. A method was developed for the analysis of 36 trace organic contaminants (TOrCs) including pharmaceuticals, pesticides, steroid hormones (androgens, progestins, and glucocorticoids), personal care products and polyfluorinated compounds (PFCs) using a single solid phase extraction (SPE) technique with ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The method was applied to a variety of water matrices to demonstrate method performance and reliability.RESULTS:UHPLC-MS/MS in both positive and negative electrospray ionization (ESI) modes was employed to achieve optimum sensitivity while reducing sample analysis time (<20min) compared with previously published methods. The detection limits for most compounds was lower than 1.0 picogram on the column while reporting limits in water ranged from 0.1 to 15ng/L based on the extraction of a 1L sample and concentration to 1mL. Recoveries in ultrapure water for most compounds were between 90-110%, while recoveries in surface water and wastewater were in the range of 39-121% and 38-141% respectively. The analytical method was successfully applied to analyze samples across several different water matrices including wastewater, groundwater, surface water and drinking water at different stages of the treatment. Among several compounds detected in wastewater, sucralose and TCPP showed the highest concentrations.CONCLUSION:The proposed method is sensitive, rapid and robusthence it can be used to analyze a large variety of trace organic compounds in different water matrixes.
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Joshi, Manishkumar Dilipkumar. "Synthesis of New Classes of Ionic Liquids and Polymeric Ionic Liquids and their Applications in Microextraction Techniques." University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1372871956.
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