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Rotating-disk thin-layer chromatography /DuPont, Deborah Louise. January 1980 (has links)
Thesis (M.S.)--Ohio State University, 1980. / Includes bibliographical references (leaves 100-104). Available online via OhioLINK's ETD Center
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An investigation into some aspects of the thin layer chromatographic assay of Pregnanediol with emphasis on the suitability of this method as a clinical laboratory routinePaton, L T January 1969 (has links)
Pregnanediol (5B Pregnane- 3⋉- 20⋉- dial) is the chief urinary metabolite of progesterone, and as such is important in that variations in its concentration reflect variations in progesterone secretion. Estimations of pregnanediol concentration are therefore of considerable interest to the obstetrician and gynaecologist. Pregnanediol was first identified in the urine of pregnant women in 1929 by Marrian. Nearly ten years later Venning developed a method by which the glucuronic acid ester of pregnanediol could be extracted from the urine and its concentration gravimetrically determined. Numerous variations of the Venning theme were published in the next few years, each being claimed by its authors to be an improvement on the original. Most of these involved the estimation of the conjugated form, and it was a while before the advantage of estimating the hydrolysed aglycone was realized. Hydrolysis, when it was practised, resolved itself into two methods - namely, hydrolysis by heating the urine with a mineral acid, and enzymic hydrolysis by incubation with beta-glucuronidase. Acid hydrolysis, while producing a less clean hydrolysate, is more rapid and convenient than enzyme hydrolysis, and is used in the Klapper method which is presently the most widely used method in clinical studies. Klapper employs a double chromategraphic column separation of pregnanediol followed by colorimetric evaluation. Variations of Klapper's method have also appeared and not a few investigators have published comparisons of the various methods. Klapper himself compared his method to certain other methods and concluded that his was definitely superior. Of the accuracy of the Klapper method there is no doubt. Subsequent methods have proved more sensitive, but in terms of practicability Klapper's is the method of choice. As was pointed out with some complacency, "practicability is most satisfactory, one technician readily performing some twenty determinations in one week." In contrast to the flood of criticisms, comparisons, variations, claims and counter-claims which accompanied the publication of the abovementioned methods, the thin layer chromatographic method perfected by Waldi attracted very little attention. It is very much more rapid than all other existing techniques, is very sensitive, specific and of acceptable accuracy. In an attempt to ensure its usefulness for clinical and medical research laboratories, the Waldi method has been marketed in 'kit' form. It is intended primarily as a diagnostic aid in establishing pregnancy, and as such it might have enjoyed considerable application had it not been for the advent of the immunological method of pregnancy diagnosis which is very much more rapid. Nevertheless, the Waldi method, used purely as a means of assessing the pregnanediol content of the urine is extremely useful, and it is the purpose of this investigation to establish this usefulness, especially with respect to routine clinical investigations. The validity of some diagnoses which are based on pregnanediol assay results, is also investigated. As it is impossible to explain the significance or usefulness of a pregnanediol assay without first explaining the functions of progesterone, some time and space must be expended in a brief description, firstly, of the role played by progesterone in the phenomenon of the menstrual cycle, and secondly, of its vital importance in pregnancy. It must be realized that progesterone is only one of the many hormones involved in these events, but, in order to limit the introduction of extraneous detail, no mention is made of the other hormonal participants except when necessary for the understanding of the whole. It may be mentioned here that much of the evidence that was used for the elucidation of the functions and origins of progesterone, was derived from studies of its metabolite, pregnanediol.
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In situ analysis of thin layer chromatography plates using an imaging detector /Gianelli, Mary Lucille. January 1981 (has links)
Thesis (Ph. D.)--University of Washington, 1981. / Vita. Bibliography: leaves [131]-135.
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A comparative thin layer chromatography study of different brands of five herbal remediesUrbani, Carla 29 February 2008 (has links)
ABSTRACT
The belief that herbal remedies are less invasive on the human body than conventional
medicine and the return of the consumer to a more natural lifestyle, has led to the
development of a multitude of remedies, with many different uses. Because the use of
these herbal remedies has increased drastically in the last decade, it is essential that
the quality and efficacy of these products are well regulated. One of the objectives in
this study includes the investigation of the presence of marker metabolites in five
herbal remedies, namely Serenoa repens, Silybum marianum, Hypericum perforatum,
Echinacea purpurea and Gingko biloba. Although most of the brands tested contained
the active ingredients assayed for, a few exceptions were found. However, because
this study used only thin layer chromatography for analysis of products, verification of
these results should be obtained using other more modern methods for example high
pressure liquid chromatography. Four brands of Serenoa repens were selected and
assayed for the presence of -sitosterol. All four brands tested indicated the presence
of -sitosterol. Five brands of Hypericum perforatum were selected and assayed for
the presence of hypericin, rutin and chlorogenic acid. Four of the five products tested
indicated the presence of hypericin, while three of five products indicated the presence
of rutin and chlorogenic acid. Five brands of Echinacea purpurea were selected and
assayed for the presence of -sitosterol, chlorogenic and caffeic acid. Three of the
five products indicated the presence of -sitosterol, while only one of the five products
contained chlorogenic acid. Caffeic acid was present in 3 of the 5 products. Seven
brands of Gingko biloba were selected and assayed for the presence of rutin and
bilobalide. Five of the seven products indicated the presence of rutin and bilobalide.
Four brands of Silybum marianum were selected and assayed for the presence of both
taxifolin and sylibin. Only two of the four products contained both taxifolin and
silybin. The second objective of this study is to provide a literature review of the five
herbal remedies mentioned above. Amongst the topics discussed were uses of these
plants, evidence from studies conducted, chemistry and mechanism of action of the
active molecules contained in the plants.
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Separation and detection of cellooligosaccharides on cellulose thin-layer chromatographySookavatana, Narumon 11 June 2001 (has links)
Linear oligosacchardies of 1,4 linked β-D-glucopyranose are commonly
referred to as cellodextrins (CD) or cellooligosaccharides (CO). They are of interest
to those working in disciplines involving cellulose chemistry because they are often
used as model substrates for cellulose itself. They are of interest to food scientists
and nutritionists because they are easily incorporated into foods as non-digestible
oligosaccharides, a category of food ingredients that is thought to be beneficial lo
human health. The intent of the research presented in this thesis was to evaluate the
potential of using cellulose supports for the chromatographic separation of soluble
CDs differing in their degree of polymerization (DP; a numerical value indicating
the number of glucose substituents per molecule). Soluble CDs range in DP from 2
to 8. Thin layer chromatography (TLC), using cellulose-coated TLC plates, was
used as a model chromatographic system.
Mixed CD preparations, containing CDs ranging in DP from 2 to 8 were
prepared by incomplete acid-catalyzed hydrolysis of cellulose. The DP profiles of
the different CD preparations were qualitatively demonstrated by TLC using silica-coated
plates, an organic solvent-based mobile phase, and a standard carbohydrate
visualizing reagent (p-anisaldehye in sulfuric acid). CD-preparations were then
chromatographed on cellulose-coated TLC plates. Visualization of the
chromatographed CDs was accomplished using a silver nitrate-sodium hydroxide
reagent system, a reducing-sugar visualizing reagent. The silver nitrate-sodium
hydroxide system was found to be the most appropriate, based on detection limits,
simplicity and safety, of the several visualization reagents tested.
Eight different mobile phases, all aqueous-based, were tested as potential
solvents for the resolution of CDs, differing in DP, on cellulose-coated tlc plates at
room temperature. The optimum solvent was found to be 60% ethanol/40% water.
This solvent clearly resolved CDs of DP 3, 4 and 5. CD preparations
chromatographed with the same mobile phase, but with silica-coated TLC plates,
were not resolved. These combined results suggest that the TLC system with the
cellulose stationary phase behaves similar to an affinity system, since silica and
cellulose are both relatively hydrophilic stationary phases (i.e. both systems are
typically considered examples of normal phase adsorption chromatography). The
results further illustrate that cellulose supports have potential for use in the
preparation of CDs of defined DP. / Graduation date: 2002
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Planar chromatography coupled with mass spectrometryMullis, James Onis, Jr. 12 1900 (has links)
No description available.
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Thin-layer gel-filtration studies of adenosine deaminase in normal and pathological human seraFrazier, Ronald Burdette January 1980 (has links)
Previous studies of serum adenosine deaminase have neglected consideration of the two molecular forms of this enzyme that exist in human tissues. The purpose of this study was to survey the distribution of these forms in normal and pathological human sera. Both molecular forms were present in normal serum, though the small form predominated. This form also predominates in lymphocytes, erythrocytes, and in tissues with high specific activity of this enzyme. The ratio of the two forms is different for plasma and serum and can change with sample storage. The activity of the small form varied over a wider range than the activity of the large form in normal serum. Many pathological samples showed an altered distribution of the two forms. This study demonstrates the potential usefulness of serum forms of adenosine deaminase for distinguishing some pathological conditions.
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Cation analysis by thin-layer chromatography and reflectance spectroscopyZaye, David F January 1968 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii, 1968. / Bibliography: leaves [80]-87. / xi, 87 l illus., tables
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Reactions of alcohols and organophosphonates on tungsten trioxide epitaxial films /Ma, Shuguo, January 2003 (has links) (PDF)
Thesis (Ph.D.) in Chemistry--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 138-149 ).
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Reactions of Alcohols and Organophosphonates on Tungsten Trioxide Epitaxial FilmsMa, Shuguo January 2003 (has links) (PDF)
No description available.
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