Development of a Sol-Gel-Based Thin-Layer Chromatography Stationary Phase for in-situ Infrared Analysis

Persistent Link:
http://hdl.handle.net/10150/193589
Title:
Development of a Sol-Gel-Based Thin-Layer Chromatography Stationary Phase for in-situ Infrared Analysis
Author:
Jones, Linda
Issue Date:
2008
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:
A sol-gel stationary phase was developed for in-situ infrared (IR) detection of analytes on thin-layer chromatography (TLC) plates. These sol-gel-based TLC plates have improved optical properties compared with conventional TLC plates in IR spectroscopic analysis. Samples can be analyzed in transmission geometry, requiring no special attachments. The sol-gel-based TLC plates demonstrate significantly better light throughput and a wider spectral range than conventional TLC plates analyzed in diffuse reflectance geometries.The sol-gel precursor, methyltrimethoxyorthosilicate (MTES), was templated with cetyltrimethylammonium bromide (CTAB) and urea in order to form a porous sol-gel. Aerosol deposition was used to apply the sol-gel solution onto either glass slides or silicon wafers within an enclosed chamber. Many variables were studied to determine their effect on the quality of the sol-gel stationary phases, including the ratio of MTES:methanol:water:CTAB:urea:HCl:, gelation times and temperatures, and deposition rate. Sol-gel films prepared using MTES/methanol/water/CTAB at ratios of 1 : 20 : 7 : 0.2 containing 5 wt% urea (relative to MTES) and pH 1.5 were crack-free, mechanically stable, and uniform in appearance. The films were tens of microns thick with a highly interconnected porous structure.For chromatographic separations, the films exhibited good solvent migration velocity and could be repeatedly washed and reused for TLC separations without showing degradation in the separation. Several different classes of compounds, including polyaromatic hydrocarbons and dyes, were successfully separated. Theoretical plate values measured on the MTES-based sol-gel films were comparable to those obtained on commercially available TLC plates.
Type:
text; Electronic Dissertation
Keywords:
thin layer chromatography; infrared detection; sol-gel chemistry
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Denton, M. Bonner

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleDevelopment of a Sol-Gel-Based Thin-Layer Chromatography Stationary Phase for in-situ Infrared Analysisen_US
dc.creatorJones, Lindaen_US
dc.contributor.authorJones, Lindaen_US
dc.date.issued2008en_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.abstractA sol-gel stationary phase was developed for in-situ infrared (IR) detection of analytes on thin-layer chromatography (TLC) plates. These sol-gel-based TLC plates have improved optical properties compared with conventional TLC plates in IR spectroscopic analysis. Samples can be analyzed in transmission geometry, requiring no special attachments. The sol-gel-based TLC plates demonstrate significantly better light throughput and a wider spectral range than conventional TLC plates analyzed in diffuse reflectance geometries.The sol-gel precursor, methyltrimethoxyorthosilicate (MTES), was templated with cetyltrimethylammonium bromide (CTAB) and urea in order to form a porous sol-gel. Aerosol deposition was used to apply the sol-gel solution onto either glass slides or silicon wafers within an enclosed chamber. Many variables were studied to determine their effect on the quality of the sol-gel stationary phases, including the ratio of MTES:methanol:water:CTAB:urea:HCl:, gelation times and temperatures, and deposition rate. Sol-gel films prepared using MTES/methanol/water/CTAB at ratios of 1 : 20 : 7 : 0.2 containing 5 wt% urea (relative to MTES) and pH 1.5 were crack-free, mechanically stable, and uniform in appearance. The films were tens of microns thick with a highly interconnected porous structure.For chromatographic separations, the films exhibited good solvent migration velocity and could be repeatedly washed and reused for TLC separations without showing degradation in the separation. Several different classes of compounds, including polyaromatic hydrocarbons and dyes, were successfully separated. Theoretical plate values measured on the MTES-based sol-gel films were comparable to those obtained on commercially available TLC plates.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectthin layer chromatographyen_US
dc.subjectinfrared detectionen_US
dc.subjectsol-gel chemistryen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairDenton, M. Bonneren_US
dc.contributor.committeememberBurke, Michaelen_US
dc.contributor.committeememberDowns, Roberten_US
dc.contributor.committeememberBates, Roberten_US
dc.contributor.committeememberHruby, Victoren_US
dc.identifier.proquest2547en_US
dc.identifier.oclc659748477en_US
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