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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 82 for “"preconcentration"”.
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Membrane-Based Protein Preconcentration Microfluidic Devices
… devices. I have made membrane-based protein preconcentration systems in capillary and microchip designs to increase the detectability of low-concentration biological samples. A photopolymerized ion-permeable membrane interfaced with a microchannel in poly(methyl methacrylate) (PMMA) formed …
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Nanoporous Silicon in Gas Preconcentration and Sensing
This thesis addresses new developments in the sensing of chemical compounds in the gas phase, a topic which is of great importance in almost every sector. Volatile organic compounds, or VOCs, are emitted by many processes, and have significant effects on human health and the environment. …
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Low-Cost Manufacturing of Electrokinetic Preconcentration Systems
… manufacturable implementation of a sample preconcentration device that uses the ion concentration polarization phenomena to filter charged biomolecules from a solution. Compared to previous electrokinetic concentrators, our device prioritizes manufacturability and sample throughput so that …
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Integrated mining and preconcentration systems for nickel sulfide ores
As part of a strategic research initiative at UBC to design and evaluate integrated underground mining and mineral processing systems, work has been done to determine how to utilize the coarse rejects of pre-concentration in the underground environment. An amenability study for nine orebodies from …
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Field sampling and microcolumn preconcentration techniques in inductively coupled plasma spectrometry.
… device, which gives high sample integrity and preconcentration.
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Metal -Organic Frameworks: Their Microwave Synthesis and Applications as Adsorbents for Preconcentration
MASS method provides us a simple and fast approach to quickly build a library of other new MOFs. In the third part, we demonstrate the syntheses of 14 new MOF materials based on the MASS method. Each has been tested by TGA to explore its sorption behavior with 4 different vapors. The structures for …
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Immunoassay sensitivity and kinetic enhancement in cell culture media using electrokinetic preconcentration
… prior to antibody-antigen binding, or preconcentration. Using this scheme, we have demonstrated a 100 fold sensitivity improvement for antigens directly from cell media without sample preparation when compared with immunoassays without preconcentration.
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Separation, preconcentration and determination of rare earth elements by inductively coupled plasma emission spectroscopy
Rare earth elements, (REE), at ug g⁻¹ levels are used for studies of petrogenisis of different geological materials. For these studies, the REE must be determined precisely. An analytical program was established using an IL 200 Inductively Coupled Plasma, (ICP), spectrometer for the determination …
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Improved mass spectrometry characterization of organic compounds using analyte preconcentration and radio-frequency ionization.
… research projects focus on the use of analyte preconcentration and radio-frequency ionization to improve sensitive characterization of organic compounds with MS. A home-built post-column cryogenic trap (PCCT) coupled to a commercial gas chromatography (GC)/quadrupole MS system was utilized for …
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Electrohydrodynamic focusing and light propagation in 2-dimensional microfluidic devices for preconcentration of low abundance bioanalytes
… transmission to aid the development of species preconcentration and identification. EHDF is an equilibrium focusing method, where a target ion becomes stationary under the influence of a hydrodynamic force opposed by an electromigration force. To achieve this one force must have a non-zero …
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Selective preconcentration of platinum and rhodium from hydrochloric acid media containing tin (II) chloride using polyurethane foam
The potentially quantitative and selective sorption of chloro-(trichlorostannato)-platinum(II) and -rhodium (III/I) complex anions by polyurethane foams has been examined. Quantitative separation of platinum(II) from iridium and ruthenium has been achieved. Rhodium( III) is similarly sorbed by …
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IN-SITU PRECONCENTRATION OF TRACE METALS IN NATURAL WATERS AND BRINES WITH ANALYSIS BY FLOW INJECTION ATOMIC SPECTROMETRY
… methodologies involving on-line sample preconcentration and matrix removal for the determination of trace elements in natural waters and brines using ICP-MS and ICPAES detection for the determination of a suite of trace elements including cadmium, cobalt, copper, lead manganese, nickel, …
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Analysis of Clinically Important Compounds Using Electrophoretic Separation Techniques Coupled to Time-of-Flight Mass Spectrometry
… coupled to TOFMS without employing any preconcentration scheme beyond sample work up by solid phase extraction (SPE). Using this hyphenated approach, submicromolar levels of catecholamines and metanephrines in normal human urine and indolamines in human plasma were detected after the …
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Capillary Electrophoresis of Proteins with Selective On-line Affinity Monoliths
… technique is frequently challenging. Coupling preconcentration techniques with CE greatly improves the CLOD. An on-line preconcentration-CE method that can selectively preconcentrate any protein for which an antibody is available would be very useful for the analysis of low abundance proteins …
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THE DETERMINATION OF TRACE METALS IN CONCENTRATED BRINES FOR PROCESS CONTROL
… through unchanged. This allowed the simultaneous preconcentration of the analytes and matrix removal. Following the preconcentration step, the retained metals were backflushed from the column, using a lactic acid mobile phase, and separated by cation exchange chromatography. Detection was based …
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A preconcentration-spectographic method for the determination of trace elements in plant materials and the application of the biogeochemical method at the Silver Mine lead deposit Cape Breton, Nova Scotia
A combined chemical preconcentration-spectrographic a-c spark method was developed for the simultaneous estimation of the total content of selected trace elements in vegetation. Procedures for adapting it to the determination of the composition of large numbers of plant and soil samples were …
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Mercury-Thiourea Complex Ion Chromatography With on-Line Cold Vapor Generation and Atomic Fluorescence Spectrometric Detection (hgtu/ic-Cvafs)
… and thiourea leaching coupled to on-line thiolic preconcentration has been designed for use with the system and shown to give accurate results with biotic reference materials and have limits of detection of ∼10 pg g-1 with 100 mg of dried sample. A specific solvent extraction for quantitative …
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Development of HPLC Techniques for the Analysis of Trace Metal Species in the Primary Coolant of a Pressurised Water Reactor
… liquid chromatography (HPLC), coupled with preconcentration of sample was an ideal technique. A HPLC system was developed to determine trace metal species in simulated PWR primary coolant. - In order to achieve the desired detection limit an online preconcentration system had to be …
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Electrically Controlled Formation and Release of Admicelles for Solid Phase Extraction
… on surfaces for the purpose of analyte preconcentration prior to chromatographic analysis are presented. The surfactant layer serves as the “stationary phase” in a solid phase extraction sorbent scenario. Analytes are adsorbed on this layer, and then released from the solid phase via …
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Improving vacuum ultraviolet spectroscopy using instrumental modifications and chemometric applications.
… combination of VUV spectroscopy with cryogenic preconcentration. With cryogenic preconcentration, gases can be trapped over an extended period of time and then released quickly. Combination with cryogenic preconcentration improves the poor sensitivity and small dynamic range of VUV spectroscopy. …
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