Geometry induced fluorescence modifications: An experimental study of micron-size capillaries.

Persistent Link:
http://hdl.handle.net/10150/186352
Title:
Geometry induced fluorescence modifications: An experimental study of micron-size capillaries.
Author:
Hunter, Boyd Vern.
Issue Date:
1993
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Capillary Zone Electrophoresis (CZE) is an important analytical technique used to analyze the chemical makeup of small samples with volumes on the order of picoliters. However, in the quest for smaller sample volumes, smaller capillaries are used. This research has focussed on analyzing the optical properties of these small capillaries to determine if and how they affect the fluorescence spectrum of the molecules inside the capillary. In the course of this research we have determined that for fluorescent liquids, there is no evidence of angular dependencies in the fluorescent emissions for the total intensity or the linear polarization components of the total intensity. This angular isotropy does not show any noticeable temperature dependence. We have also determined that the fluorescence spectrum from these molecules is not smooth. Even with weak reflections from the capillary inner walls, enough feedback exists to superimpose resonances on the otherwise smooth spectrum. If the reflectivity is high enough, typically when the core index of refraction is higher than the capillary's index, it is possible to cause some materials to lase. This lasing has been shown in a variety of systems by several researchers. However, total internal reflection is not required for resonances, although weak, to be present. Resonances between the cavity dimensions and the incident laser light are also responsible for a nonlinearity in fluorescence intensity normalized to volume. This normalized intensity nonlinearity may also be due partially to photoinduced decay processes that were observed. In any event, some care is required in the selection of capillary size for CZE in order to maximize fluorescence intensity per unit volume from the capillary. The use of small capillaries exposes the experimenter to a wide variety of physical phenomena which make their use and appropriate interpretation of the data somewhat complex, although manageable.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Dissertations, Academic.; Chemistry, Analytic.; Optics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Physics; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Bickel, William S.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleGeometry induced fluorescence modifications: An experimental study of micron-size capillaries.en_US
dc.creatorHunter, Boyd Vern.en_US
dc.contributor.authorHunter, Boyd Vern.en_US
dc.date.issued1993en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractCapillary Zone Electrophoresis (CZE) is an important analytical technique used to analyze the chemical makeup of small samples with volumes on the order of picoliters. However, in the quest for smaller sample volumes, smaller capillaries are used. This research has focussed on analyzing the optical properties of these small capillaries to determine if and how they affect the fluorescence spectrum of the molecules inside the capillary. In the course of this research we have determined that for fluorescent liquids, there is no evidence of angular dependencies in the fluorescent emissions for the total intensity or the linear polarization components of the total intensity. This angular isotropy does not show any noticeable temperature dependence. We have also determined that the fluorescence spectrum from these molecules is not smooth. Even with weak reflections from the capillary inner walls, enough feedback exists to superimpose resonances on the otherwise smooth spectrum. If the reflectivity is high enough, typically when the core index of refraction is higher than the capillary's index, it is possible to cause some materials to lase. This lasing has been shown in a variety of systems by several researchers. However, total internal reflection is not required for resonances, although weak, to be present. Resonances between the cavity dimensions and the incident laser light are also responsible for a nonlinearity in fluorescence intensity normalized to volume. This normalized intensity nonlinearity may also be due partially to photoinduced decay processes that were observed. In any event, some care is required in the selection of capillary size for CZE in order to maximize fluorescence intensity per unit volume from the capillary. The use of small capillaries exposes the experimenter to a wide variety of physical phenomena which make their use and appropriate interpretation of the data somewhat complex, although manageable.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectDissertations, Academic.en_US
dc.subjectChemistry, Analytic.en_US
dc.subjectOptics.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePhysicsen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairBickel, William S.en_US
dc.contributor.committeememberStoner, Jr., John O.en_US
dc.contributor.committeememberGarcia, J. D.en_US
dc.contributor.committeememberMilster, Thomas D.en_US
dc.identifier.proquest9408385en_US
dc.identifier.oclc720380364en_US
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