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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The use of acrylamide disc electrophoresis in the study of isozymes in two populations of sea anemones

Pardy, Rosevelt Lawrence, 1940- 1966 (has links)
No description available.
2

Disc electrophoresis of enzymes in Ulmus Spp. and Picea glauca

Feret, Peter P. 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.
3

Procedures for sample clean-up and concentration in capillary zone electrophoresis for determination of drugs in biosamples

Pálmarsdóttir, Sveinbjörg. 1996 (has links)
Thesis (doctoral)--University of Lund, 1996.
4

Procedures for sample clean-up and concentration in capillary zone electrophoresis for determination of drugs in biosamples

Pálmarsdóttir, Sveinbjörg. 1996 (has links)
Thesis (doctoral)--University of Lund, 1996.
5

Stanovení protaminů kapilární zónovou elektroforézou Capillary zone electrophoresis determination of protamines

Malý, Michal 2015 (has links)
This work deals with development and optimization of a method for separation and detection of pro- tamines using capillary zone electrophoresis. The developed method uses a fused silica capillary with inner diameter of 50 µm and effective length of 41,5 cm. Driving voltage is 30 kV. Background electrolyte is aque- ous solution of 45 mmol dm−3 phosphoric acid. Analyte is detected spectrophotometrically at wavelength of 200 nm. Sample is injected hydrodynamically. The method allows for determination of protamines in the concentration range between 11 µg ml−1 to 1000 µg ml−1 , limit of detection is 4 µg ml−1 . Viablity of the method has been verified with a real sample of NPH insulin injection. For sufficiently sensitive detection of protamines in NPH insuline it is necessary to prepare the sample in acidic environment. For the pur- poses of this work the sample was acidified by addition of background electrolyte into the sample so that the background electrolyte concentration in the resulting solution of the sample was 18 mmol dm−3 . The main advantage of the method is the rapid analysis, migration time of the analyte is about 2 min. Disadvantage of the method in comparison to alternate methods using CZE or RP-HPLC is the inability to separate individ- ual protamine peptides. This disadvantage...
6

Capillary electrophoresis and related techniques for the analysis of fresh water algal toxins.

John, Wilson. 1997 (has links)
As cyanobacteria (also known as blue green algae) produce a range of cyclic peptides which are highly toxic, capillary electrophoresis and associated techniques have been investigated to assess their applicability for toxin monitoring in the water bodies of kwaZulu Natal, South Africa. Capillary electrophoresis (CE) is a technique in which charged molecules can be efficiently separated in a buffer solution within a capillary tube under the influence of a strong electric field. Two CE modes, namely capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) were initially evaluated using a laboratory-built CE instrument. The former mode lacked selectivity due to the similar charge to size ratio of the algal toxins. However, with the latter mode, incorporation of a surfactant (sodium dodecyl sulphate) into the buffer, produced sufficient resolution between components. Parameters including surfactant concentration, buffer ionic strength, buffer pH and operating voltage were systematically optimized to separate the four algal toxins under investigation (microcystin YR, microcystin LR, microcystin RR and nodularin). The optimum separation conditions were: 30 mM borax, 9 mM sodium dodecyl sulphate, pH 9.18, 30 kV applied voltage, 10 s hydrodynamic injection, 70 cm x 50 Ilm Ld. bare fused silica capillary (LEFF 40 cm) and UV detection at 238 nm. Under these conditions, typical detection limits were in the low ng/IlL range (14.13 ng/IlL for microcystin LR to 29.85 ng/ILL for nodularin). The MECC method was evaluated in terms of migration time precision, efficiency and resolution, peak area and normalised peak area precision. Standard deviation values for retention times acquired using replicate electrokinetic injections ranged from 0.018 to 0.054 and 0.069 to 0.148 for hydrodynamic injections. Normalised peak area precision for replicate hydrodynamic injections were in the range 84 to 97 % RSD, while improved % RSD values of 11.5 to 18.7 were achieved for electrokinetic injections. Due to poor precision resulting from the lack of automation on the laboratory built CE system, poor correlation between increasing concentration and a corresponding change in normalised peak areas were achieved. The MECC method developed was applied to the analysis of an algal scum extract to illustrate the technique. A general problem with CE is that it suffers from poor detection sensitivity. Hence in this study, alternative injection modes, sample concentration strategies and alternative detection techniques were investigated in an attempt to improve detection limits for algal toxins. Using optimized electrokinetic injection conditions, detection limits were five to ten times better than those obtained with hydrodynamic injections. On-line sample concentration methods were partially successful. Field amplified back and forth MECC in which analyte injected in the entire column volume and subsequently focused in a narrow band by manipulating the electric field, resulted in an enormous sensitivity enhancement that ranged from 197 times for microcystin RR to 777 times for microcystin YR when compared to hydrodynamic injections. Field amplified sample stacking (FASI) was ineffective for toxin preconcentration, while electro-extraction produced detection limits ranging from 0.27 ng/J.tL for microcystin YR to 1.08 ng/J.tL for microcystin RR. Solid phase extraction, in which analytes are first trapped and concentrated on HPLC material in a cartridge and then eluted in a more concentrated form for injection, was found to be practical only in the offline mode. A concentration detection limit of less than 0.002 ng/J.tL was obtained. Attempts with on-line solid phase extraction failed due to problems associated with coupling the cartridge with the separation capillary. Finally, laser induced fluorescence (LIF) detection was investigated as an alternative to UV detection. Unfortunately, the algal toxins were not amenable to LIF detection because tagging with the fluorescent moiety, fluorescein isothiocyanate (FITC), was prevented by the stereochemistry of these cyclic peptides. A comparative study between HPLC and MECC revealed that the former displayed poor efficiency peaks and long analysis times for toxin analysis. However HPLC was superior in terms of retention time precision (0.12 to 0.64 % RSD) and area precision (1.78 to 2.86 % RSD). Mass detection limits for MECC (0.0142 to 0.0603 ng) were far superior to those achieved by HPLC (0.55 to 1.025 ng). In addition to HPLC and MECC, a preliminary investigation of micro-high performance liquid chromatography (J.tHPLC) and capillary electrochromatography (CEC) for the analysis of algal toxins was made using 50 J.tm Ld. capillary columns packed in-house, with reverse phase HPLC packing material. Thesis (M.Sc.)-University of Natal, 1997.
7

Studium acidobazických vlastností derivátů bilirubinu metodou kapilární zónové elektroforesy Study of acid-base properties of bilirubin derivatives using capillary zone electrophoresis

Kupcová, Kristýna 2012 (has links)
in English The concise summary of literary information about bilirubin and its structure derivative ranarubin is the topic of this thesis. The experimental part is dedicated to investigation of some properties of this substances and their comparison. The rate of degradation and acid- base behaviour was monitored under the laboratory conditions using capillary zone electrophoresis. The results point to differences in their behaviour.
8

Komplexační rovnováhy beta-blokátorů v CZE Complex equilibriums of beta-blockers in CZE

Kanizsová, Lívia 2016 (has links)
Drugs used in the pharmaceutical industry often occur as a mixture of several isomers with a different biological activity. In a case that some isomer provides an undesirable side effect, it is important to separate it from the mixture and check the chiral purity of a drug. Capillary zone electrophoresis plays a significant role in chiral separations. A different affinity of isomers to complexation reagent is used for their separation from each other. The extent of their interaction is characterized by the complexation constant. Most commonly the cyclodextrins are used for the chiral separations of β-blockers and they could be in neutral or charged form. They probably interact with them through the creation of inclusion complexes. A successful baseline enantioseparation of all the β-blockers that have been studied, labetalol, pindolol, alprenolol and atenolol, was provided by using the background electrolyte containing charged cyclodextrins. The highest resolution of peaks was observed using sulfated cyclodextrins.
9

Stanovení tenzidů metodou kapilární zónové elektroforézy. Determination of surfactants by capillary zone electrophoresis.

Tůmová, Klára 2015 (has links)
Surfactans are synthetically made surface-active ingredients contained in washing and cleaning products. They decrease the surface tension and remove dirt. Surfactans can be divided into four basic classes: anionic, cationic, non-inonic and ampholitic. The most commonly used are the anionic ones. Thanks to the massive use they penetrate into waste water and can disturb the environment. This thesis is focused on the optimization methods and the determination of three anionic surfactants by capillary zone electrophoresis.
10

Electrochemical Methods for Drug Characterisation and Transdermal Delivery : Capillary Zone Electrophoresis, Conductometry, and Iontophoresis

Merclin, Nadia 2003 (has links)

This thesis concerns the development and utilisation of techniques for characterisation and transdermal delivery of various systems for pharmaceutical applications.

The degree of dissociation of drug molecules and the mobilities of the different species formed are essential factors affecting the rate of drug delivery by iontophoresis. Hence, determination of drug mobility parameters and equilibrium constants are important for the development of iontophoretic systems. With capillary zone electrophoresis using a partial filling technique and methyl-β-cyclodextrin as chiral selector, the enantiomers of orciprenaline were separated. The association constants between the enantiomers of the drug and the selector were also evaluated. Precision conductometry studies were performed for the hydrochloride salts of lidocaine and 5-aminolevulinic acid in aqueous propylene glycol and water as media, respectively.

Iontophoresis is a technique for drug delivery where charged molecules are transported into and through skin by application of a weak direct electrical current. The drugs 5-aminolevulinic acid and its methyl ester were used as model compounds and incorporated in two different drug delivery vehicles, a sponge phase and carbopol gel. The bicontinuous structure of the sponge phase, constituted of monoolein and a mixture of propylene glycol and water, makes it interesting for use in iontophoretic delivery, since ions can move more or less freely in the aqueous as well as in the lipid domains. Furthermore, all three components are known for their penetration enhancing abilities. Hydrogels like carbopol gels are interesting media with respect to iontophoretic studies, since devices for iontophoresis often utilize hydrogels as contact interfaces between the skin and the electrodes. The results indicate that the transport achieved iontophoretically using the gel (1 % active substance) was comparable with the passive delivery of clinically used formulations (16 % - 20 % active substance).

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