Dissertations / Theses: 'Capillary electrophoresis with mass spectrometry'

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Vuorensola, Katariina. "Capillary electrophoresis and capillary electrophoresis-mass spectrometry in catecholamine studies." Helsinki : University of Helsinki, 2002. http://ethesis.helsinki.fi/julkaisut/mat/kemia/vk/vuorensola/.

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Mironov, Gleb. "Capillary Electrophoresis - Mass Spectrometry for Bioanalysis." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33004.

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Bioanalysis is a subdivision of analytical chemistry and deals with biological analytes such as metabolites, proteins, nucleic acids, small molecules, virus particles and entire cells. The rationale of my thesis was to achieve two goals: (i) develop a set of ready to use methods (ii) which are capable providing exact concentrations of analytes as well as kinetic and thermodynamic parameters of their interactions. To investigate interactions between biomolecules special conditions are required which do not interfere with the course if biomolecule interactions. Establishing these conditions and optimization of separation and detection parameters can be tedious and can take longer than actual analysis of samples. I developed a variety of Capillary Electrophoresis – Mass Spectrometry (CE-MS) methods suitable for bionalalysis. CE-MS establishes a new paradigm that separation methods together with MS detection can be used as comprehensive kinetic tools. Most previous attempts to use chromatography and electrophoresis for studying nucleic acid interactions were restricted to assuming slow or no equilibrium between reactants. Kinetic CE (KCE) shows that non-zero kinetics and structural dynamics must be taken into account when separation happens. KCE-MS could be a valuable supplement to IM-MS due to the separation of ions in solution according to their size-to-charge ratio. These methods allowed to reveal new facts about biomolecules and added novel data to the bank of the mankind knowledge. For the best of my knowledge, kinetic parameters for TG2 and thrombin G-quadruplex folding were reported for the first time. I developed a homogeneous method to determine kon, koff and Kd of fast and weak noncovalent interactions between multiple unlabeled ligands (small molecule drugs) and an oligosaccharide (α- or β-cyclodextrin) simultaneously in one capillary microreactor. It has been shown for the first time that KCE can be used to separate and detect the slowly interconverting open and closed conformations of human TG2. It allowed the first direct measurement of the Kd value for calcium binding. Sixteen new substrates were discovered for three aminotransferases (AAT, BCAT, and DAAT). In addition, Viral qCE showed a feasibility to analyse both the count of intact viral particles and sample nucleic acid contamination.

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Goodwin, Lee. "Capillary electrophoresis-mass spectrometry and tandem mass spectrometry studies of ionic agrochemicals." Thesis, University of York, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398906.

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Palmer, Martin. "Development and application of capillary electrophoresis/mass spectrometry." Thesis, Sheffield Hallam University, 2000. http://shura.shu.ac.uk/20181/.

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Capillary electrophoresis is a generic term used to describe separation techniques employing high voltages. In its simplest form, capillary zone electrophoresis (CZE), separations are based on the differential migration of charged analytes under the influence of a high electric field. CZE offers several advantages over other separation techniques, such as high performance liquid chromatography (HPLC). These include higher separation efficiency, enhanced resolution and reduced analysis time. In addition, small injection volumes (nanolitres cf. microlitres for HPLC) and low solvent consumption make CZE an attractive alternative to HPLC. Unfortunately, CZE is not amenable to neutral species, therefore alternative electroseparation methods are employed for neutrals, e.g. capillary electrochromatography (CEC) and micellar electrokinetic chromatography (MEKC), so therefore CZE can be treated as a complementary technique to HPLC.Mass spectrometry (MS) has previously been demonstrated to be a sensitive, selective and near-universal detector. Analytes must be ionised in order to be detected; thus, CZE (which also requires ions) seems an ideal separation technique for combining with MS.CZE/MS interfacing would seem problematic; the linear flow velocity through the capillary is significantly less than that required by appropriate MS ionisation sources (e.g. continuous-flow fast atom bombardment and electrospray). In addition, it is necessary to provide a ground for the separation voltage within the interface. However, interfacing of CZE and MS was first reported in 1987. Since then three distinct interface designs have been developed, co-axial sheath flow, liquid junction and the use of a low flow electrospray (nanospray) interface. Co-axial sheath flow and liquid junction methods serve to increase the overall flow rate of CZE to a suitable level for MS, whereas nanospray is a low flow ionisation technique that accepts similar flow rates to those provided by CZE.The work presented in this thesis details the off-line development of a CZE separation of a pharmaceutical product (cimetidine) and related impurities. The separation was then transferred to mass spectral detection on a commercial triple quadrupole MS instrument employing home-built co-axial sheath flow (electrospray) and nanospray interfaces and the data obtained evaluated. The separation was subsequently transferred to an orthogonal acceleration time-of-flight MS (oa-ToF) for the exact mass determination of the narrow electrophoretic peaks. The feasibility of hydrogen/deuterium exchange via the sheath liquid for CZE/MS has been investigated using model pharmaceutical compounds and preliminary work is presented. An application of CZE/MS for the separation of nicotine and ten of its metabolites has been developed. This method could be further developed into a quantitative assay for nicotine metabolites in biological fluids and suggestions for future work in this area are made.

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Soliman, Laiel. "Capillary electrophoresis-mass spectrometry separation of isomeric biological compounds." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43419.

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Current prostate cancer (PCa) diagnosis based on prostate-specific antigen (PSA) has been gradually losing its credibility over the last decade due to contradictory results in published literature and clinical practice. Recently, a group of potential PCa biomarkers in urine, particularly sarcosine, was found to increase significantly as the cancer progressed to metastasis. In Chapter 2, we report a simple, robust, and reproducible capillary electrophoresis–electrospray ionization–tandem mass spectrometry (CE–ESI-MS/MS) method for the determination of sarcosine and other representative potential biomarkers in pooled urine. A solid phase extraction (SPE) technique was optimized for maximum recovery of sarcosine. With no derivatization step, excellent resolution between sarcosine and its isomers (α-alanine and β-alanine) was achieved. A separate non-SPE method was also developed for quantitative determination of highly concentrated urinary metabolites. Precision for intra- and inter-day standard addition calibration of sarcosine were found to be within 15%, whereas intra-day precisions for the rest of the metabolites varied from 0.03 to 13.4%. Acceptable intra-day and inter-day accuracies, ranging from 80 to 124%, were obtained for sarcosine and the other metabolites. The second part of the thesis takes on a more challenging task. The importance of chiral separation in pharmaceutical, agriculture, and food industries has driven separation scientists to develop more powerful methodologies in conjunction with the structural capabilities of mass spectrometry. In Chapter 3, chiral separation of D- and L-tryptophan was compared on a bare-fused silica capillary and a PEI-coated capillary. Although a higher resolution was observed for uncoated capillaries, analytes were found to migrate slower resulting to longer analysis times (tm > 20 min). With shorter migration times (tm < 10 min) and acceptable resolution, further investigations on different factors that could affect enantioseparation were conducted on a coated capillary. Highly-sulfated cyclodextrins (HS-CDs), a group of charged CD derivatives, were also utilized for the separation of several racemic amino acids. Resolution with HS-CDs was found to be superior to using native CDs. Unfortunately, due to time constraint, no MS work was presented as the chiral CE/MS work is still currently in progress.

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Liu, Chun-Sheng. "Development and application of capillary electrophoresis-electrospray mass spectrometry." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ60321.pdf.

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Keski-Hynnilä, Helena. "Liquid chromatography - and capillary electrophoresis - mass spectrometry in glucuronide analysis." Helsinki : University of Helsinki, 2002. http://ethesis.helsinki.fi/julkaisut/mat/farma/vk/keski-hynnila/.

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Eastwood, Catherine Rachel. "The development of capillary isotachophoresis for use with electrospray mass spectrometry." Thesis, University of Huddersfield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327143.

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Baynham, Michael Thomas. "Microcolumn separations coupled to mass spectrometry : suitability for drug metabolism studies." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342000.

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Bateman, Kevin Patrick. "Sensitivity enhancement for capillary zone electrophoresis-mass spectrometry, developments and applications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24731.pdf.

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Craig, Sarah Jane. "The analysis of complex glycoproteins by capillary electrophoresis and mass spectrometry." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283361.

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Bowerbank, Christopher Ryan. "Comprehensive Isotachophoresis-Capillary Electrophoresis Coupled to Time-of-Flight Mass Spectrometry." BYU ScholarsArchive, 2001. https://scholarsarchive.byu.edu/etd/6084.

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Isotachophoresis (ITP) coupled to capillary zone electrophoresis (CE) in a comprehensive manner was used to separate mixture components in both insufficient and sufficient concentrations without heart-cutting or splitting. Examples of comprehensive ITP-CE involving multiple CE injections of preconcentrated ITP zones are demonstrated. In the comprehensive arrangement, all of the sample in the first dimension (ITP) is subjected to analysis in the second dimension (CE), without significant sample loss or decrease in sample detectability resulting from removal of a portion of the sample. This is especially important for analytes at low concentrations which may form a single mixed zone instead of individual ITP zones. Direct online coupling of ITP to CE in this comprehensive arrangement involved the use of columns having different diameters with one directly inserted inside the other. A counterflow was applied when the isotachophoretic sample stack reached the bifurcation point. Large volume (10 µL) injections were made using an electrically-insulated commercial polymeric rotary valve injector for increased reproducibility compared to previous comprehensive ITP-CE studies, with ITP and CE retention time RSD values ranging from 2-5%. An ultraviolet (UV) detector positioned at the bifurcation point was used to determine the beginning of CE injection. Application of a splitting voltage at the bifurcation point showed no affect on analyte transfer into the CE column. By using multiple injections of the ITP band(s), CE column overloading was not observed. Online capillary isotachophoresis (ITP) and comprehensive isotachophoresis-capillary electrophoresis (ITP-CE) were also coupled with electrospray ionization (ESI)-orthogonal acceleration time-of-flight mass spectrometry (TOFMS). Separations were performed using 200 µm I.D. and 50 µM I.D. polyvinylalcohol (PVA)-coated fused silica capillaries for ITP and CE, respectively. Both ITP and ITP-CE were coupled to TOFMS for analysis of sufficient (10-5 M) and insufficient (10-6-10-7 M) concentrations of angiotensins in mixtures. ITP-TOFMS of a single mixed zone of five angiotensins (3 x 10-7 M) showed that ion suppression due to the co-elution of angiotensin III in the electrospray significantly reduced the ionization of other analytes. A practical solution to the detection difficulties for ITP mixed zones involved the insertion of a CE separation between the ITP and TOFMS for online preconcentration, separation, and identification in one system.

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Baidoo, Edward Emmanuel Kweku. "Determination of nicotine and its metabolites by capillary electrophoresis and mass spectrometry." Thesis, Sheffield Hallam University, 2003. http://shura.shu.ac.uk/19300/.

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In England an estimated, 284,000 patients are admitted to NHS hospitals each year due to disease caused by smoking. It is estimated that half of all teenagers who are currently smoking will die from diseases caused by tobacco if they continue to smoke. An estimated one quarter of smokers will die after 70 years of age and one quarter before, with those dying before 70 losing on average 23 years of life. It is the addictive nature of nicotine that exacerbates the toxicities of the other components of cigarette smoke. The Royal College of Physicians has affirmed that the way in which nicotine causes addiction is similar to drugs such as heroin and cocaine. Thus studies of nicotine metabolism are of great importance since they determine the extent of which the addictive nature of nicotine can influence smoking behaviour and hence the onset of smoking related illnesses. In this area of research capillary electrophoresis (CE) is still in its infancy. But with its high resolution and high number of theoretical plates achieved, CE makes for an attractive separating device for coupling with a mass spectrometer (MS). The overall aims of this work were to produce a sensitive, highly selective, and simple CE-sample stacking/MS assay for the measurement of nicotine and its metabolites in urine, to develop a highly sensitive transient isotachophoretic/MS method, that yields detection limits comparable to that observed by HPLC/MS and with a separation efficiency to match that of CE-sample stacking/MS, and finally to characterise the metabolic activity of cytochrome P450 (e.g. CYP2D6) in the placenta, with respect to nicotine, from a representative in-vitro human trophoblast-like cell line, BeWo, via HPLC/MS and CE/UV. Analysis of urine samples was accompanied by sample clean up via SPE to ensure the appropriate removal of inorganic salts. An optimised hydrodynamic and electrokinetic injection method (HE injection) was used for CE-sample stacking/MS. HE-sample stacking/MS brought about lower detection limits (LODs of nicotine and cotinine, by CE-sample stacking/ MS (via HE injection), were found to be 0.11 and 2.25 mug/ mL, respectively) when compared to sample stacking/MS via hydrodynamic or electrokinetic injection alone. The added selectivity that the selected ion monitoring mode of MS provided ensured the clear identification of nicotine and its metabolites in urine. A counterflow transient isotachophoresis (tITP) method was developed, with MS detection, for the analysis of even lower analyte concentrations. Limits of detection for both nicotine (0.03 mug/ mL) and cotinine (0.34 mug/ mL), via HE-tlTP/MS, were considerably lower than those obtained by HE injection-sample stacking/MS, suggesting that HE-tlTP/MS could be used complementary to HE injection-sample stacking/MS. When HPLC/MS and CE/UV were used to analyse cytochrome p450 activity in the human trophoblast-like BeWo cell line, it was clear from our data that nicotine metabolism was observed. Thus it is probable that CYP mediated processes play an important role in nicotine metabolism in the placenta. When compared to HPLC/MS both HE-sample stacking/MS and HE-tlTP/MS exhibited higher resolutions and peak efficiencies; with HE-tITP/MS exhibiting comparable limits of detection and quantitation to those obtained by HPLC/MS with respect to nicotine, but not cotinine. The major improvements to the coaxial interface performance and sensitivity enhancements, has made CE/MS an attractive alternative to HPLC/MS for the determination of nicotine and its' metabolites from biological matrices.

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Taylor, Karen Anne. "Developments in, and applications of, capillary electrophoresis inductively-coupled plasma mass spectrometry." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/33877.

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This project has set out to design and optimise a robust and efficient interface for capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) and to investigate the application of the technique in elemental speciation studies. An interface was constructed using a commercial microconcentric nebuliser (MCN) and a cyclonic spray chamber. The cyclonic spray chamber was designed specifically to provide rapid sample response and washout and to minimise sample dispersion. Isoforms of the heavy metal binding protein, metallothionein, were separated and the bound metals detected to characterise the interface. Suction from the self-aspirating nebuliser was identified as the principal factor controlling electrophoretic resolution.

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Jayo, Roxana Gabriela. "Capillary electrophoresis mass spectrometry for the characterization of glycoproteins and N-glycans." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/51488.

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Glycosylation of proteins is ubiquitous and has the ability to significantly alter the biological and biophysical properties of proteins. The need to study structure-function relationships of glycans in a living organism requires the continuous development of rapid and sensitive technologies for the characterization of glycan components. In recent years, a broad range of technologies have evolved to provide new developments and emerging glycomics techniques. In this thesis we present the development of new methodologies based on capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS) for the study of protein N-glycosylation in complex biological systems and therapeutic recombinant drugs. Our approach involves the use of a flow-through microvial, a novel technology that provides a robust and easy-to use strategy for interfacing CE separation with MS detection. In chapter 2, we report a simple and robust CE-ESI-MS methodology for comprehensive characterization of glycosylated proteins at the level of intact protein, enzymatically released glycopeptide and glycans. In chapter 3, we characterize a complex set of enzymatically released N-glycans from a recombinant therapeutic drug that revealed extensive glycan heterogeneity. The study demonstrated the potential of our approach to complement established techniques for glycan characterization of therapeutic glycoproteins in the pharmaceutical industry. Chapters 4 and 5 of this thesis are devoted study protein glycosylation of relevant biological systems. In chapter 4, O-acetylated N-glycans from fish serum were characterized in their native state and the structural variations of their isomeric species were investigated by tandem MS approaches. The developed CE-MS methods may be useful not only for the characterization of acetylation of complex glycans but also to study other types of glycan modifications in different contexts. In chapter 5, we present CE-MS methodologies for characterizing protein N-glycosylation in human serum associated with prostate cancer and asthma. Comparison of glycan compositions and relative abundances revealed abnormal glycosylation in prostate cancer and asthma serum. The capability of our CE-ESI-MS method to perform global glycan profiling of human serum demonstrates its potential for comprehensive glycan profiling in the context of malignancies and for the discovery of glycan disease markers with high selectivity and specificity.
Science, Faculty of
Chemistry, Department of
Graduate

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Zheng, Bingxue. "Quantitative Analysis and Determination of Microcystin in water by Capillary Electrophoresis Mass Spectrometry." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1538.

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The presence of harmful algal blooms (HAB) is a growing concern in aquatic environments. Among HAB organisms, cyanobacteria are of special concern because they have been reported worldwide to cause environmental and human health problem through contamination of drinking water. Although several analytical approaches have been applied to monitoring cyanobacteria toxins, conventional methods are costly and time-consuming so that analyses take weeks for field sampling and subsequent lab analysis. Capillary electrophoresis (CE) becomes a particularly suitable analytical separation method that can couple very small samples and rapid separations to a wide range of selective and sensitive detection techniques. This paper demonstrates a method for rapid separation and identification of four microcystin variants commonly found in aquatic environments. CE coupled to UV and electrospray ionization time-of-flight mass spectrometry (ESI-TOF) procedures were developed. All four analytes were separated within 6 minutes. The ESI-TOF experiment provides accurate molecular information, which further identifies analytes.

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Schoenherr, Regine M. "CE-microreactor-CE-MS-MS for protein analysis /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/11593.

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Zhong, Xuefei. "Design and applications of an improved capillary electrophoresis - electrospray ionization - mass spectrometry interface." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42877.

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A novel capillary electrophoresis – electrospray ionization – mass spectrometry (CE-ESI-MS) interface has been developed to provide a robust, user-friendly and more sensitive alternative interface strategy. The new interface uses a flow-through microvial design and a bevelled sprayer tip geometry. The capillary column terminus is surrounded by a tapered stainless steel hollow needle, and the interior of the needle tip acts as the CE outlet while its exterior tip surface provides the electrode surface for electrospray ionization. A chemical modifier is supplied to the open-ended microvial at the CE outlet through a standard tee union, serving the purpose of maintaining electrical continuity, and supporting a stable electrospray. The chemical modifier supplied through the flow-through microvial can also be used to improve the compatibility of CE effluent with electrospray ionization. The bevelled sprayer tip design extends the optimal flow rate range for ESI and requires lower flow rate compared to conventional blunt tips or symmetrically tapered sprayer tips. This feature leads to reduced dilution effect caused by the chemical modifier solution and improves the detection sensitivity. The mass transport process in the flow-through microvial was investigated by numerical simulation and experimental comparison of on-column and post-column detection. Both approaches demonstrated that the laminar flow profile inside the microvial does not significantly distort the peak shape and the major characteristics of the eluted peaks are maintained when the modifier flow rate is properly adjusted. The chemical modifier solution in the flow-through microvial enables CE separation without electroosmotic flow (EOF). One useful application of this feature is interfacing online capillary isoelectric focusing (cIEF) with ESI-MS detection, which could be a potential replacement in many applications of two-dimensional gel electrophoresis (2DE) for protein analysis in the future. The final part of the thesis elucidates the electric field distribution in the ESI source with an atmospheric ion lens, which could be incorporated in the CE-ESI-MS interface to improve the ionization and sampling efficiency in the future.

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Wycherley, Darren. "The application of capillary electrophoresis and mass spectrometry to clinical and environmental problems." Thesis, Open University, 1996. http://oro.open.ac.uk/19806/.

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Using capillary electrophoresis (CE) as a separation technique has allowed analytes, previously difficult to separate by standard methods because they did not conform to requirements for GC or HPLC, to be separated with speed and great efficiency. The only requirements for CE analysis are that the sample is soluble in a liquid matrix and that analytes are present as positive or negative ions whilst in this matrix. This technique has been used here to analyse both clinical and environmental samples, some as cations and others boron-containing complexes as anions. Samples were analysed using a combination of CE alone, mass spectrometry alone and also coupled capillary electrophoresis/electrospray mass spectrometry (CE/ES). Clinically orientated analytes, dipeptides in urine and acylcamitines from blood spots were examined and peaks detected directly via uv absorbance. The environmental samples analysed included those which contained chromophoric or non-chromophoric herbicides as well as those containing diisocyanates. Analytes were either detected in their native form as with the dipeptides and chromophoric herbicides, or more typically after derivatisation to improve their absorbance characteristics. The exception was the non-chromophoric herbicides which were detected via indirect uv. CE was an experimental technique for the analysis of all these compounds, except for the dipeptides, all the others having originally been analysed using HPLC or GC methods. In each case an evaluation of the CE method was performed to determine the suitability of the method. By analysing standards in each case, it was possible to confirm that the technique was suitable for qualitative and quantitative analysis of each class of compound. CE proved to be a viable technique for the separation of all classes of compound dealt with in this thesis. However the method could not be relied upon to confirm the identity of these analytes by their migration time alone. To identify the analytes, experiments were carried out to couple CE with a mass spectrometer. Two techniques of mass spectrometry were used within this thesis, fast atom bombardment and electrospray but only electrospray ionisation mass spectrometry was used to couple to capillary electrophoresis and was the only mass spectrometric technique used to analyse clinical and environmental samples. CE instruments were successfully coupled to an electrospray mass spectrometer which then became the detector. Mass/charge ratio measurements were obtained for each analyte used and these allowed the unambiguous identification of each analyte. Other work involved using CE, ES and FAI3 mass spectrometry, to develop a new technique to detect diol containing compounds. This involved complexing the diol with a boron-containing acid to produce an anion which could then be detected using ES and FAB mass spectrometric methods. This work was viewed as a possible technique for the detection of diol containing lipids found within some body fluids.

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Lau, Simon Sheen Man. "The application of capillary electrophoresis-hydrogen deuterium exchange-mass spectrometry in peptide analysis." Thesis, University of Strathclyde, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431775.

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Huikko, Katri. "Capillary electrophoresis- and microchip-mass spectrometry interfaces and their utilization in bisphosphonate analysis." Helsinki : University of Helsinki, 2003. http://ethesis.helsinki.fi/julkaisut/mat/farma/vk/huikko/.

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Said, Nassur. "Characterization of therapeutic proteins by capillary electrophoresis (CE) coupled to mass spectrometry (MS)." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAF048/document.

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Les anticorps monoclonaux (mAbs) sont des glycoprotéines complexes possédant de nombreuses micro-hétérogénéités qui peuvent influencer leur efficacité dans l’organisme. Il est par conséquent nécessaire de développer des méthodes analytiques robustes, sensibles et spécifiques pour les caractériser avec la plus grande précision. L’objectif de cette thèse a été de développer des méthodes analytiques permettant la caractérisation fine et à différents niveaux d’un anticorps monoclonal, le cetuximab, ainsi qu’un anticorps monoclonal conjugués à un principe actif, le brentuximab vedotin, sur des couplages direct ou indirect de l’électrophorèse capillaire et la spectrométrie de masse. Dans une première partie, une approche middle-up protéomique du cetuximab a été réalisé sur le couplage indirect CZE-UV/MALDI-MS afin de séparer et caractériser les variants de charges du fragment F/2 et F(ab)’2 ainsi que la caractérisation top-down des fragments Fc/2. Ensuite une nouvelle stratégie indirecte CZE-UV/nanoESI-MS a été développée pour permettre la caractérisation fine de ce mAbs partiellement digéré. Enfin un couplage direct par CESI-MS a été développé pour permettre l’analyse rapide et précise du cetuximab middle-up. Dans une deuxième partie, la combinaison d’analyse de mAbs d’intact, middle-up et bottom-up protéomique a été réalisée sur le couplage CZE-UV/nanoESI-MS et CESI-MS. Cela a permis la caractérisation à différent niveau du brentuximab vedotin. Cette méthodologie a permis l’analyse du DAR, l’identification de fragments conjugués, la caractérisation simultanée de la séquence complète de l’anticorps, d’un grand nombre de modifications post-traductionnelles, la caractérisation des peptides conjugués ainsi que l’identification d’ions diagnostiques du principe actif
Monoclonal antibodies (mAbs) are highly complex glycoproteins having a lot of micro-heterogeneities which can influence their effectiveness. As a consequence, it is necessary to develop robust analytical methods, sensitive and specific to characterize them with high accuracy. The purpose of this thesis was to develop analytical methods allowing the multi-level characterization of monoclonal antibody (cetuximab), and antibody drug conjugates (brentuximab vedotin), using on-online or off-line capillary electrophoresis – mass spectrometry coupling. In the first section, a middle-up proteomic approach of cetuximab was carried out using Off-line CZE-UV/MALDI-MS coupling to separate and to characterize Fc/2 and F(ab)’2 charge variants. A top-down characterization of Fc/2 fragments was also employed. Then a new strategy off-line CZE-UV/nanoESI-MS was used to allow the characterization of this partially digest mAbs. Finally, an online coupling by CESI-MS was developed to allow the fast and accurate analysis of middle-up cetuximab. In a second part, the combination of intact, middle-up and bottom-up proteomic carried out on CZE-UV/nanoESI-MS and CESI coupling allowed the most exhaustive characterization of brentuximab vedotin. This methodology allowed the analyze of DAR, the identification of fragments drug conjugates, the simultaneous characterization of the complete structure of antibody, a significant number of post-translational modifications, all peptides drug conjugates and the identification of diagnostic ions

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Zhou, Feng. "Protein characterization by capillary isoelectric focusing electrophoresis, reversed phase liquid chromatography and mass spectrometry." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 103 p, 2008. http://proquest.umi.com/pqdweb?did=1456289241&sid=4&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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Elhamili, Anisa. "Development of Capillary Electrophoresis Methods Coupled to Mass Spectrometry for Biomedical and Pharmaceutical Analysis." Doctoral thesis, Uppsala universitet, Analytisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-143814.

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The analysis of large intact proteins and complex biological samples containing drug molecules is a common complicated task for many scientists. However, due to the importance of these molecules, there is a growing interest in pharmaceutical and medicinal research to develop rapid, highly sensitive and efficient analytical techniques. The advantages of capillary electrophoresis (CE) in combination with mass spectrometry (MS) provide a powerful analytical tool. However, further improvement and development of these techniques are required to extend their utility and to meet the challenges of selected analytes. Thus, the scope of this thesis deals with the development of novel analytical methods to achieve efficient and high performance analysis of peptides, intact proteins, digests of complex samples and basic pharmaceutical drug compounds in biological matrices. Implementation of CE for routine analysis of proteins and complex samples is constrained by the partial adsorption to the capillary wall. Consequently, the use of surface modified capillaries is required to control the surface properties and prevent analyte adsorption. In this thesis, analyte adsorption was successfully prevented using tailored covalent cationic (M7C4I) and electrostatic cationic (PVPy-Me) coatings. Rapid and efficient separations of peptides, proteins and digests of complex samples such as cerebrospinal fluids were obtained with these coatings. The M7C4I coating showed a distinct ability to handle large intact proteins with a molecular size of over 0.5 MDa. The highest peak efficiencies and surprisingly high peak stacking effects were obtained by adding salts to the protein samples. The effect of salt additives on peak efficiencies of intact proteins was further demonstrated and compared using different surface modified capillaries. Additionally, rapid CE-ESI-MS quantification of pharmaceutical drug molecules in human plasma was performed after a SCX-SPE sample preparation method using the M7C4I coating. In conclusion, the results presented in this thesis show the strong potential of CE in combination with MS using electrospray ionization (ESI) for the analysis of peptides and large intact proteins and the applicability for clinical monitoring of the levels of pharmaceutical drug molecules in human plasma with high sensitivity and efficiency.
Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 734

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Hui, Ying-ngai, and 許英毅. "Development and application of chip-based and capillary-based capillary electrophoresis: inductivelycoupled plasma atomic emission spectroscopy and mass spectrometry." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B45014802.

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Hui, Ying-ngai. "Development and application of chip-based and capillary-based capillary electrophoresis : inductively coupled plasma atomic emission spectroscopy and mass spectrometry /." View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B31031250.

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Thakur, Anup P. "METABOLITE ANALYSIS OF CLOSTRIDIUM THERMOCELLUM USING CAPILLARY ELECTROPHORESIS BASED TECHNIQUES." UKnowledge, 2008. http://uknowledge.uky.edu/gradschool_diss/647.

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Clostridium thermocellum is a thermophilic bacterium that converts biomass to ethanol directly; however, high sensitivity of this bacterium toward ethanol limits its commercial utility. To elucidate the effect of ethanol on the growth of this bacterium a metabolite analysis of C. thermocellum was performed. The hypothesis of the project was that exogenous ethanol alters the metabolite profile of C. thermocellum. For metabolite analysis, capillary electrophoresis-electrospray ionization-mass spectrometry method (CE-ESI-MS) was developed due to highly polar and charged nature of metabolites. To increase the sensitivity of CE-ESI-MS, several parameters at the ESI interface were optimized. The application of 50% isopropanol as a sheath liquid increased sensitivity for metabolite analysis dramatically. Trimethylamine acetate (pH 10) was used as background electrolyte (BGE) due to its ability to separate the structural isomers of glucose phosphate. For metabolite sample preparation, novel methods for quenching and CE compatible metabolite extraction protocols were developed. Newly developed protocols were applied to metabolite analysis of wild type (WT) and ethanol adapted (EA) strains of C. thermocellum grown in batch cultures. Significant differences were found in key intracellular metabolites such as NAD+ and pyruvic acid. Intracellular concentrations of NAD+ were low in EA cells compared to WT cells and pyruvic acid was only detected in EA cells. To further understand the effect of ethanol on metabolite fluxes, WT and EA cells were grown in increasing concentrations of ethanol and the metabolite profile for each ethanol treatment was obtained. Significant changes were found in intracellular metabolite concentrations. Metabolic data showed that the glycolysis process in WT cells was obstructed due to exogenous ethanol which was evident from accumulation of G6P. On the other hand, no such accumulation of G6P was observed in the EA strain; however pyruvate began to accumulate in EA strain. These changes in intracellular metabolite concentrations due to perturbation of exogenous ethanol supported the hypothesis. Also, this investigation revealed a correlation between ethanol and metabolite profile changes and was able to explain a possible mechanism of growth inhibition of C. thermocellum which will certainly help genetic engineers to develop superior strains of C. thermocellum for commercial cellulosic ethanol production.

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Zuberovic, Aida. "Surface Modified Capillaries in Capillary Electrophoresis Coupled to Mass Spectrometry : Method Development and Exploration of the Potential of Capillary Electrophoresis as a Proteomic Tool." Doctoral thesis, Uppsala universitet, Analytisk kemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9554.

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The increased knowledge about the complexity of the physiological processes increases the demand on the analytical techniques employed to explore them. A comprehensive analysis of the entire sample content is today the most common approach to investigate the molecular interplay behind a physiological deviation. For this purpose a method that offers a number of important properties, such as speed and simplicity, high resolution and sensitivity, minimal sample volume requirements, cost efficiency and robustness, possibility of automation, high-throughput and wide application range of analysis is requested. Capillary electrophoresis (CE) coupled to mass spectrometry (MS) has a great potential and fulfils many of these criteria. However, further developments and improvements of these techniques and their combination are required to meet the challenges of complex biological samples. Protein analysis using CE is a challenging task due to protein adsorption to the negatively charged fused-silica capillary wall. This is especially emphasised with increased basicity and size of proteins and peptides. In this thesis, the adsorption problem was addressed by using an in-house developed physically adsorbed polyamine coating, named PolyE-323. The coating procedure is fast and simple that generates a coating stable over a wide pH range, 2-11. By coupling PolyE-323 modified capillaries to MS, either using electrospray ionisation (ESI) or matrix-assisted laser desorption/ionisation (MALDI), successful analysis of peptides, proteins and complex samples, such as protein digests and crude human body fluids were obtained. The possibilities of using CE-MALDI-MS/MS as a proteomic tool, combined with a proper sample preparation, are further demonstrated by applying high-abundant protein depletion in combination with a peptide derivatisation step or isoelectric focusing (IEF). These approaches were applied in profiling of the proteomes of human cerebrospinal fluid (CSF) and human follicular fluid (hFF), respectively. Finally, a multiplexed quantitative proteomic analysis was performed on a set of ventricular cerebrospinal fluid (vCSF) samples from a patient with traumatic brain injury (TBI) to follow relative changes in protein patterns during the recovery process. The results presented in this thesis confirm the potential of CE, in combination with MS, as a valuable choice in the analysis of complex biological samples and clinical applications.

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Melzer, Tanja [Verfasser]. "Hyphenation of capillary isotachophoresis and capillary electrophoresis-mass spectrometry for online preconcentration and separation of amino acids / Tanja Melzer." Tübingen : Universitätsbibliothek Tübingen, 2021. http://nbn-resolving.de/urn:nbn:de:bsz:21-dspace-1128961.

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Zhou, Wei. "Application of Affinity Chromatography Combined with Capillary Electrophoresis or Mass Spectrometry in the Biochemical Analysis." NCSU, 2000. http://www.lib.ncsu.edu/theses/available/etd-20000117-220916.

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The focus of the research has been to develop combined techniques, such as affinity chromatography combined with capillary electrophoresis or mass spectrometry, for the structural analysis of biologically important proteins. In the first part of the research, a method that allows the direct analysis the peptides affinity-bound to the immobilized metal ion media by matrix assisted laser desorption/ionization mass spectrometry (MALDI/MS) has been developed and applied to detect sequence errors of recombinant proteins occuring at the N-terminus and to locate phosphorylation sites in proteins. This method allows the fast identification of two recombinant proteins with expression errors, one is proteins p24, a major capsid protein of human immunodeficiency virus (HIV), the other is Vif, a viral infectivity factor required for the efficient transmission of free virus. Phsophorylation sites on proteins p53 and p21 that are involved in determining cellular response to DNA damage are also detected using this method. Huge gain in terms of selectivity, sensitivity and structural information are achieved with minimal sample consumption. In the second part of the research, affinity capillary electrophoresis (ACE) has been applied to evaluate biomolecular interactions, such as protein-drug and antibody-antigen interactions, and to better understand the interaction. ACE with laser induced fluorescence detection (LIF) is used to systematically evaluate binding between phosphorothioate oligodeoxynucleotides (Sd, potential anti-HIV drugs) and viral envelope glycoprotein HIV-1 gp120. The results show that the interaction has a strong dependence on the sulfur phosphorothioate backbone. Chain length and the sequence of Sd also affect the ability of binding to gp120. The results may provide useful information to clinical trial. ACE is also used to examine the effect of each residue of the epitope of HIV-1 capsid protein p24 on their affinity to an anti-p24 monoclonal antibody. Each amino acid within epitope is successively substituted by alanine, and the effect of the substitutes on their affinity for the antibody is examined by ACE. We are able to determine the relative importance of each amino acid within the epitope to the binding affinity of the peptide. The results provide a better understanding of these interactions. High separation power and ease of automation of ACE offer an effective and rapid means to study of these types of biological interaction.

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Zhao, Shuai Sherry. "Applications of capillary electrophoresis - mass spectrometry interfaced by a flow-thourgh microvial electrospray ionization sprayer." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/51508.

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Capillary electrophoresis – electrospray ionization – mass spectrometry (CE-ESI-MS) combines the superior separation capability of CE and detection and characterization ability of MS. Different CE separation modes can be coupled to ESI-MS, employing an interface with a flow-through microvial. In the first part of the thesis, recent development of CE and CE-MS applications in the analysis of complex samples are reviewed. Capillary isoelectric focusing (cIEF) is an important tool for the separation and characterization of amphoteric molecules based on isoelectric points. Minute structural changes on a large protein can result in changes in isoelectric point, and the changes can be detected by slab gel isoelectric focusing or capillary isoelectric focusing. A systematic study on the interactions among carrier ampholytes, sample media and capillary inner coatings was carried out to provide guidelines for choosing feasible combinations that can achieve isoelectric focusing and successful chemical mobilizations. Within the 0.1%-1% (w/v) carrier ampholytes concentration range, small forward EOFs will ensure a higher chance of good focusing and successful electrophoretic mobilization, while a negative EOF will hinder these processes. Feasible combinations of experimental conditions are summarized. Using the optimized conditions, we reported the direct observation of the shape of focused ampholyte bands in the cIEF process by online cIEF- ESI-MS. The ampholyte bands directly detected by MS have the potential to enable a more accurate pI determination for unknown amphoteric molecules. Immunoglobulin G from rabbit serum is used to demonstrate this possibility. In Chapter 6, a CE-MS method was developed to monitor the concentration variations of major nutrients and/or metabolites in human embryonic stem cell CA1S culture medium over a culturing cycle. Concentration changes for nutrients and/or metabolites in the culturing media provided information on the cell growth behavior without destructing living cells. In the last part of the thesis, an atmospheric ion lens was applied to the flow-through microvial CE-ESI-MS interface to improve the electrospray ionization and sampling efficiency. A mixture of amino acids was tested to show the increased signal-to-noise ratios. The atmospheric ion lens also gives more flexibility when choosing the EOF and chemical modifier flow rates.
Science, Faculty of
Chemistry, Department of
Graduate

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Jones, Megan Renee. "Investigation of the Barrett's esophagus cell line by capillary electrophoresis /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/8573.

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Xu, Jiawei. "Analysis of reproduction proteins from butterflies." Thesis, KTH, Skolan för kemivetenskap (CHE), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-44404.

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Male butterflies have some certain pathways to prevent the female butterfly which has mated with them from mating with other butterflies. Research shows that some proteins from the male butterflies may play an important role in this mechanism. To investigate how the pathway works, the proteins contained in the spermatophore which is injected into the female butterfly by the male one during mating are very important. In this study, the butterfly spermatophore proteins were mainly studied. The proper procedures to obtain the spermatophore from the female body were developed. Since capillary electrophoresis (CE) has many advantages for separation and detection of low amounts of sample, it was used in this study in order to separate the proteins obtained from spermatophores. Finally, Mass Spectrometry (MS) was performed to analyze the proteins after separation in order to identify the proteins. This thesis mainly introduced the following points: 1. The method for obtaining spermatophores from butterfly bodies and the procedures for extracting proteins from spermatophores. 2. Optimized methods and conditions of Capillary Zone Electrophoresis (CZE) for butterfly spermatophore proteins. Several CZE methods and sets of conditions were compared in order to find the optimized ones. 3. Protein samples were applied to Mass Spectrometry (MS) to try to analyze and identify them. Moreover, the effect of using ZiptipsTM for sample pretreatment was discussed.

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Kato, Dawn M. "APPLICATIONS OF GAS CHROMATOGRAPHY/MASS SPECTROMETRY AND CAPILLARY ELECTROPHORESIS FOR THE ANALYSIS OF LIGNOCELLULOSIC BIOMASS PRETREATMENT." UKnowledge, 2014. http://uknowledge.uky.edu/chemistry_etds/45.

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The focus of this dissertation centers on the development and applications of gas chromatography/mass spectrometry and capillary electrophoresis methodologies to quantify monomeric compositions of the β-O-4 linkages in lignin. Pretreatment is a required step in the utilization of lignocellulosic biomass for biofuels. Lignin is the target of pretreatment because it hinders the accessibility of enzymes and chemicals to cellulose. The effects of pretreatment are commonly assessed utilizing enzymatic saccharification and lignin assays. However, these techniques do not elucidate the effects of pretreatment on the monomeric make up of lignin. The overarching hypothesis of this dissertation is that changes in individual monolignol content upon pretreatment can be observed from quantification. To test the hypothesis, a pretreatment, solution phase Fenton chemistry, was conducted on various lignocellulosic biomass feedstocks. Enzymatic saccharification studies showed a significant increase in glucose production upon Fenton pretreatment, however, lignin assays did not show a significant decrease in lignin content. Project two of this dissertation aimed to synthesize analytical standards in order to develop a quantitative thioacidolysis technique. The successful synthesis of the three arylglycerols were conducted utilizing and epoxidation reaction scheme which was hypothesized to produce a single diastereomer, as supported by GC/MS and chiral CE analysis. Upon method development, a quantitative thioacidolysis GC/MS method was applied to untreated and Fenton treated biomass. Results from this project revealed there was no significant change in the three lignin monomers. To verify the method, quantitative thioacidolysis GC/MS method was applied to a pretreatment method known to degrade lignin, alkaline peroxide pretreatment. The results of this project showed a significant change in monolignol concentrations upon alkaline peroxide pretreatment. Analytical degradative techniques, such as thioacidolysis, has traditionally assessed lignin as monomeric ratios. However, as this dissertation showed, upon alkaline peroxide pretreatment, no significant change was seen in the monomeric ratios, but there was a significant difference in all three monolignol concentrations. These results support the overall hypothesis that changes in individual monolignol content upon pretreatment can be observed from quantification. The works of this dissertation provides an analytical method which contributes to the elucidation of lignin.

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Fu, Hanzhuo. "Development of Advanced Capillary Electrophoresis Techniques with UV and Mass Spectrometry Detection for Forensic, Pharmaceutical and Environmental Applications." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1531.

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Capillary electrophoresis (CE) is a modern analytical technique, which is electrokinetic separation generated by high voltage and taken place inside the small capillaries. In this dissertation, several advanced capillary electrophoresis methods are presented using different approaches of CE and UV and mass spectrometry are utilized as the detection methods. Capillary electrochromatography (CEC), as one of the CE modes, is a recent developed technique which is a hybrid of capillary electrophoresis and high performance liquid chromatography (HPLC). Capillary electrochromatography exhibits advantages of both techniques. In Chapter 2, monolithic capillary column are fabricated using in situ photoinitiation polymerization method. The column was then applied for the separation of six antidepressant compounds. Meanwhile, a simple chiral separation method is developed and presented in Chapter 3. Beta cycodextrin was utilized to achieve the goal of chiral separation. Not only twelve cathinone analytes were separated, but also isomers of several analytes were enantiomerically separated. To better understand the molecular information on the analytes, the TOF-MS system was coupled with the CE. A sheath liquid and a partial filling technique (PFT) were employed to reduce the contamination of MS ionization source. Accurate molecular information was obtained. It is necessary to propose, develop, and optimize new techniques that are suitable for trace-level analysis of samples in forensic, pharmaceutical, and environmental applications. Capillary electrophoresis (CE) was selected for this task, as it requires lower amounts of samples, it simplifies sample preparation, and it has the flexibility to perform separations of neutral and charged molecules as well as enantiomers. Overall, the study demonstrates the versatility of capillary electrophoresis methods in forensic, pharmaceutical, and environmental applications.

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Marie, Anne-Lise. "Electrophorèse capillaire couplée ou non à la spectrométrie de masse pour l’évaluation ou le contrôle qualité de protéines à visée thérapeutique." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS044/document.

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Au cours de cette thèse, nous avons été amenés à développer des méthodes analytiques afin de contrôler la qualité de protéines thérapeutiques en tant que produits finis ou d'évaluer le potentiel de certaines protéines à être des candidats médicaments. Deux protéines ont été étudiées : l'albumine de sérum humain (HSA) et l'antithrombine (AT). Ces protéines diffèrent par leur structure, leur glycosylation et leurs activités biologiques. Une méthode d'électrophorèse capillaire de zone (CZE) a permis de séparer neuf formes dans des préparations commerciales d'HSA plasmatique, dont des formes native, cystéinylée, glyquées et tronquées. Une autre méthode CZE a permis de séparer plus de huit formes dans des préparations commerciales d'AT plasmatique, dont des formes native, latente et hétérodimérique. Les deux méthodes CZE développées ont permis de mettre en évidence des différences significatives quant à la composition de préparations commerciales d'HSA ou d'AT produites par cinq fournisseurs différents. Des méthodes d'électrophorèse capillaire couplée à la spectrométrie de masse (CE-MS), avec un analyseur quadripôle-temps de vol (Q-TOF) et une ionisation électrospray (ESI), ont également été développées. Ces méthodes CE-MS ont permis d'identifier non seulement de nombreuses glycoformes et formes apparentées de l'AT, mais également des formes dimériques. Une méthode CE-MS en conditions non-dénaturantes a permis de montrer que la forme native et la forme latente de l'AT (deux conformères) présentaient un spectre de masse spécifique, permettant de les différencier sans ambiguïté. Afin d'évaluer l'affinité de variants d'AT pour l'héparine, une méthode d'électrophorèse capillaire d'affinité (ACE) a été développée. Cette méthode ACE a permis d'analyser les variants d'AT directement à partir des surnageants de culture cellulaire dans lesquels ils sont produits. Ainsi, il a été montré que certains variants présentaient une affinité très élevée pour l'héparine, en accord avec les mutations réalisées. Enfin, dans le cadre des études d'affinité entre l'AT et l'héparine, nous avons exploré une méthode nouvelle basée sur l'analyse de la dispersion de Taylor (TDA)
During this Ph.D., we developed analytical methods in order to check the quality of therapeutic proteins as finished products or to assess the potential of some proteins to be drug candidates. Two proteins were studied : human serum albumin (HSA) and antithrombin (AT). These proteins are very different regarding their structure, glycosylation, and biological functions. A capillary zone electrophoresis (CZE) method enabled to separate nine forms in commercial preparations of HSA issued from human plasma, among which native, cysteinylated, glycated, and truncated forms. Another CZE method allowed separating more than eight forms in commercial preparations of AT issued from human plasma, among which native, latent, and heterodimeric forms. Both CZE methods enabled to highlight significant differences in the composition of marketed preparations produced by five competitive pharmaceutical companies. Capillary electrophoresis-mass spectrometry (CE-MS) methods, using a quadrupole-time of flight (Q-TOF) analyzer and electrospray ionization (ESI), were also developed. These CE-MS methods enabled to identify not only a high number of glycoforms and related forms of AT, but also dimeric forms. A CE-MS method developed in non-denaturing conditions showed that native and latent forms of AT (two conformers) exhibited a specific mass spectrum, allowing to unambiguously distinguish them. With the aim to assess the binding affinity of AT variants toward heparin, we developed an affinity capillary electrophoresis (ACE) method. This ACE method enabled to analyze AT variants directly from the cell culture supernatants used to produce them. It has been shown that some AT variants had a very high affinity for heparin, in good agreement with the performed mutations. Finally, a new method based on Taylor Dispersion Analysis (TDA) was investigated to study the affinity between AT issued from plasma and heparin

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Johannesson, Nina. "Column Development in Capillary Electrophoresis and Electrochromatography for Bioanalytical Applications." Doctoral thesis, Uppsala universitet, Analytisk kemi, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7124.

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Analysis of biological samples can be a difficult task. This thesis covers a broad aspect of the analytical areas of capillary electrophoresis (CE) and capillary electrochromatography (CEC) in combination with mass spectrometry (MS) that are of great importance for achieving fast, accurate and sensitive bioanalyses. A significantly time reduced and automated system for sample cleanup was developed to greatly simplify the pretreatment process of biological samples with a complex matrix. Desalting and preconcentration of species in urine was conducted and the limit of detection for the antidepressant escitalopram was lowered 10 times. This extraction devise was also successfully incorporated in a chip based platform for the possibility to be a part of multidimensional separation systems. The reduced risk of sample loss leads to improved detection limits, which are usually one the most challenging parts when working with bioanalyses. In the area of separation, a monomer surface with tailored hydrophobicity was developed to achieve rapid, high efficient separations of complex mixtures. Within five minutes a tryptic digest of a protein could be separated and then identified by a Mascot search. The applications addressed have been focused on medical conditions which are of highest interest for both physicians and patients. A high throughput analysis of the kynurenine metabolites with CE-MS offers a new method to rapidly examine samples from patients with neurological disorders. A screening study of possible biomarkers for the two different types of appendicitis, gangraenous and phlegmonous was conducted. Indicative patterns were found for both pre and post surgery of the two types of inflammation as well as between them. The divergences were traced back to the MS peaks obtained in the CE- and CEC-MS setups as possible biomarkers for the two forms of appendicitis. A preliminary study of polycystic ovary syndrome also offered some valuable results for future biomarker identification.

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Giannakoudi, Theodora. "Determination of organic phosphorus in soil samples by capillary zone electrophoresis coupled to electrospray ionization mass spectrometry." Thesis, Uppsala universitet, Analytisk kemi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-416675.

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Chemical substances that are either produced by nature or by humankind have a consequence on the environment when they are accumulated to a great extent. One of nature’s major problem is that of the eutrophication of surface waters, which is caused by inorganic and organic phosphorus compounds and, in particular, from a group known as Inositol Phosphates. There are six different forms of these inositols and are commonly found in soil and sediment samples. The conducted project was aimed to develop an analytical method that could efficiently analyze and separate all six with repeatable results. As such, soil samples were collected two times from two forest locations and two crop field locations. The first time the soil samples were left overnight to dry in a drying oven while on the second time, the samples left to dry at room temperature. When the samples were considered dry enough, they processed to reach grain size and extracted with a mixture of NaOH and Titriplex® III. The extracted soil samples, the standard solutions containing inositols, and the spiked extracted soil samples with inositol solution were all analyzed with an instrumental combination of a Capillary Electrophoresis instrument coupled manually to an Electrospray mass spectrometer, where the first was operated at reversed mode and the second at negative mode. To achieve the best feasible separation, several background electrolyte solutions were created along with a large number of sheath liquids regulated by an LC pump, two Capillary Electrophoresis methods, and twenty-five distinct MS methods, all tested through extensive screening to obtain the best possible combination of parameters. Out of the obtained results from the runs, four background electrolyte solutions, two MS methods, one sheath liquid controlled by one specific flow rate, and one Capillary Electrophoresis method exhibited promising potentials with a satisfying outcome. However, the intense pulsation of the spray cone observed for many of the runs, the manual protrusion of the Capillary Electrophoresis fused silica capillary, and some random errors, the repeatability of the method is called into question.

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Day, Jason A. "Elemental speciation and trace metal analysis using chemical separations interfaced to inductively coupled plasma - mass spectrometry." Cincinnati, Ohio : University of Cincinnati, 2001. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=ucin991666507.

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40

Wetterhall, Magnus. "Electrifying the Molecules of Life : Peptide and Protein Analysis by Capillary Electrophoresis Coupled to Electrospray Ionization Mass Spectrometry." Doctoral thesis, Uppsala University, Department of Chemistry, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4233.

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This thesis describes the current status and novel aspects of the analysis of the molecules of life, i.e. peptides and proteins, using capillary electrophoresis (CE) coupled to mass spectrometry (MS) via (sheathless) electrospray ionization (ESI). Early reports of sheathless CE-ESI-MS were plagued by limited lifetimes of the electrospray emitter. In this thesis, two new approaches, the Black Dust and the Black Jack methods, utilizing polymer-embedded graphite instead of noble metals are presented. These emitters have shown improved long-term stability and proven excellent for sheathless electrospray operation. Failure of an emitter is often caused by electrochemical reactions occurring at the emitter-liquid interface. The electrochemical properties of the graphite coated emitters were therefore evaluated by classical electrochemical methods, such as cyclic voltammetry and chronoamperometry. The graphite coated emitters showed excellent electrochemical stability and properties compared to noble metal and polymer configurations.

Analyte-wall interactions have long been known to cause problems in the CE analysis of biomolecules. This can be circumvented by internal modification of the capillary walls. Additionally, it is of outermost importance to have a stable and sufficiently high electroosmotic flow (EOF) to sustain the electrospray, when using a sheathless approach. New monomer and polymer coatings are presented for rapid and high-efficient CE-ESI-MS separations of peptides and proteins.

Furthermore, the use of CE-ESI coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) shows great potential for rapid proteomic probing of human cerebrospinal fluid. The results are comparable with more established techniques, such as liquid chromatography and two-dimensional gel electrophoresis coupled to MS. However, the CE-ESI-FTICRMS analysis has significantly lower sample consumption and faster analysis time compared to the other techniques. The applications and use of CE-ESI-MS is expected to have a bright future with continued growth as current trends of multidimensional hyphenation and microfabricated devices are further developed and explored.

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Driedger, Darcy R. "Analysis of potato glycoalkaloids by immunoassay coupled to capillary electrophoresis or matrix-assisted laser desorption/ionization mass spectrometry." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0011/NQ59948.pdf.

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42

Laude, Nicholas D. "Addressing the Neurochemical Problem: Sensitive and Selective Measurements of Neurotransmitters, Neuropeptides, and Synaptic Vesicles." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/556979.

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The neurochemical problem (1) and the directive of the neuroanalytical chemist (2) can be stated as follows: (1) The chemical space of the nervous system is populated by hundreds of neuroactive species linked through extensive biological circuits which are dynamically changing in time and space in response to myriad inputs. (2) Neurochemical analysis techniques should therefore have the appropriate temporal, spatial, and chemical resolution to study these systems, while perturbing them so minimally as to allow unfettered in vivo measurements. New tools and concepts for analytical measurements of neurotransmitters, neuropeptides, and synaptic vesicles are developed and presented in this dissertation on analytical measurements for addressing the neurochemical problem. The introduction gives a broad overview of chemical neuroscience and introduces quantitative visualization of the multidimensional resolution paradigm for analytical chemists seeking to design effective experiments. Chapters two through four detail advancements in data processing and instrument design which decrease detection limits and allow for improved spatial, temporal, chemical resolution in capillary electrophoresis measurements of neurotransmitters, metabolites, and synaptic vesicles. Chapter five discusses the development of fast-scan controlled-adsorption voltammetry which has dramatically increases the spatial and temporal resolution of basal dopamine measurement in vivo. Chapter six introduces online-preservation microdialysis as a way to overcome enzymatic degradation of endogenous opioid neuropeptides during in vivo sample collection. Because of this discovery of the secretory behavior these neuropeptides is reported in the anterior cingulate cortex (ACC), a region of the brain deeply associated with pain signaling. The advancement of peptide drugs particularly glycosylated neuropeptide analogs through new methods of mass spectrometry analysis for rapid feedback in drug development are presented in chapter 7. Chapter eight concludes this work with future directions pointing towards single-cell electrochemical and mass spectrometry measurements, shotgun-microdialysis for high-throughput screening of neurotherapeutics, preliminary data on the effect of chronic pain of endogenous opioids in the ACC, and the beginnings of in vivo neuroproteomics analysis in rodent pain models.

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Li, Jinhua. "Method development and applications of capillary electrophoresis, liquid chromatography and mass spectrometry for the separation and determination of urinary prophyrins." HKBU Institutional Repository, 2009. http://repository.hkbu.edu.hk/etd_ra/996.

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Gill, Anila Fiaz. "Insights into Sulfonated Phthalocyanines; Insights into Anionic Tetraaryl Porphyrins; Irradiation of Cationic Metalloporphyrins Bound to DNA." unrestricted, 2006. http://etd.gsu.edu/theses/available/etd-11122006-111108/.

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Thesis (Ph. D.)--Georgia State University, 2006.
Title from title screen. Dabne White Dixon, committee chair; Kathryn Betty Grant, Markus W. Germann, committee members. Electronic text (252 p. : ill., charts (some col.)) : digital, PDF file. Description based on contents viewed June 18, 2007. Includes bibliographical references.

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Peterson, Zlatuše D. "Analysis of clinically important compounds using electrophoretic separation techniques coupled to time-of-flight mass spectrometry /." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd410.pdf.

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Wang, Bin. "Utility of Cationic and Anionic Chiral Surfactants in Capillary Electrophoresis (CE) and CE Coupled to Mass Spectrometry (CE-MS)." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/chemistry_theses/16.

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The research presented in this thesis involves the application of chiral cationic and anionic surfactants for simultaneous enantioseparation of structurally similar compounds in capillary electrophoresis (CE) and CE coupled to mass spectrometry (CE-MS). The first chapter briefly introduces the fundamentals of CE and CE-MS, emphasizing the micellar electrokinetic chromatography (MEKC) and MEKC-MS techniques, as well as ionic liquids (ILs) and affinity CE (ACE). In chapter 2, a mixture of five racemic profen (PROF) drugs are simultaneously separated with the combined use of 2,3,6-tri-O-methyl-β-cyclodextrin (TM-β-CD) and IL-type surfactant, N-undecenoxycarbonyl-L-leucinol bromide (L-UCLB). Enantioseparations of these PROFs are optimized using a standard recipe containing 35.00 mM TM-β-CD, 5.00 mM sodium acetate at pH 5.0, and varying the concentration as well as chain length of the IL surfactants. The batch-to-batch reproducibility of L-UCLB is found to be acceptable in terms of enantiomeric resolution, and migration time. A competitive inhibition mechanism is proposed to investigate the ternary interactions among TM-β-CD, ILs, and PROFs. The apparent binding constant of TM-β-CD to L-UCLB is estimated by nonlinear and linear plotting methods. The binding constants of one representative PROF (e.g., fenoprofen) to TM-β-CD and to L-UCLB are estimated by a secondary plotting approach. The R- and S-fenoprofen having different binding constant values, resulting in the enantioseparation due to the synergistic effect of TM-β-CD and L-UCLB. The R- and S-configurations of barbiturates display differences in potency and biological activity. In Chapter 3, a multivariate MEKC-ESI-MS approach for the simultaneous analysis of the racemic mixture of three barbiturates is presented. The chiral selector employed is the polymeric surfactant polysodium N-undecenoxycarbonyl-L-isoleucinate. The central composite design is used to optimize the chiral resolution, decrease the total analysis time, and improve the ESI-MS signal-to-noise ratio for these barbiturates. In preliminary experiments, the ranges of the factors investigated in the multivariate approaches are determined. Then the multivariate optimizations are conducted to determine the best overall chiral resolution with shortest possible run times for barbiturates. The limit of detection of ESI-MS is several folds higher compared to the UV detection. The predicted optimum results are in good agreement with the experimental data.

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47

Willberger, Christian [Verfasser]. "Study of Complexation and Redox Reactions Using Capillary Electrophoresis Inductively Coupled Plasma Mass Spectrometry (CE-ICP-MS) / Christian Willberger." Mainz : Universitätsbibliothek Mainz, 2019. http://d-nb.info/119240498X/34.

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48

Loiselle, Teresa M. (Teresa Marie) Carleton University Dissertation Chemistry. "Analysis of selected proteins using capillary zone electrophoresis with absorbance and mass spectrometric detection." Ottawa, 1995.

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49

KANNAMKUMARATH, SASI S. "TRACE ELEMENTAL SPECIATION USING CHROMATOGRAPHY/CAPILLARY ELECTROPHORESIS COUPLED TO INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY FOR FOOD, PHARMACEUTICAL AND ENVIRONMENTAL ANALYSIS." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1085673299.

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50

VanStone, Nancy Anne. "Capillary electrophoresis-inductively coupled plasma mass spectrometry for the characterization and quantification of humic substances and their interactions with metal species." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ57999.pdf.

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Dissertations / Theses on the topic 'Capillary electrophoresis with mass spectrometry'

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