Show simple item record

Item Description Williams, Karen L. en_US 2009-07-15T17:26:56Z 2009-07-15T17:26:56Z 1994 en_US
dc.description Thesis (Ph. D.)--University of Hawaii at Manoa, 1994. en_US
dc.description Includes bibliographical references (leaves 86-90). en_US
dc.description Microfiche. en_US
dc.description xiii, 90 leaves, bound 29 cm en_US
dc.description.abstract The effect of naphthylethylcarbamate (NEC) substituent configuration on the enantioselectivity of maltooligosaccharide-based chiral stationary phases (CSPs) was investigated by preparing bonded phases derivatized with (R)-, (S)-, and racemic l-(l-naphthyl)ethyl isocyanate. Various 3,5-dinitrobenzoyl derivatized amines and amino acid esters, as well as 3,S-dinitrophenylcarbamoylated alcohols, were utilized as analytes. In most instances, retention was found to correlate with the surface concentration of the bonded ligands. The best enantioselectivity typically occurred on the S-NEC CSP. Elution order of the enantiomers provided an indication of the importance of carbamate substituent configuration in chiral recognition. The chiral carbohydrates were also found to contribute to the chiral selectivity of the CSP. The effect of mobile phase and derivatizing agent on the chromatographic behavior of the NEC CSPs was also evaluated. An isocyanate derived from (S)-6-methoxy-α-methyl-2-naphthaleneacetic acid, via an azide intermediate, was evaluated as a derivatizing agent and found to produce a CSP with comparable selectivity and superior resolution relative to the NEC CSPs. In order to gain insight into the nature of the bonded maltooligosaccharide mixture, derivatized bonded phases were prepared using maltotriose, maltopentaose, and maltoheptaose as the carbohydrate ligand. Surface concentrations of the bonded glucose oligomers were found to decrease as the carbon chain length of the oligomer increased. In general, retention, selectivity, and resolution diminished as the oligomer chain lengthened. Comparison of the selectivities of the derivatized glucose oligomer CSPs to those of a derivatized maltooligosaccharide CSP provided a measure of the relative effectiveness of the maltooligosaccharide mixture as a chiral selector. en_US
dc.language.iso en-US en_US
dc.relation Theses for the degree of Doctor of Philosophy (University of Hawaii at Manoa). Chemistry; no. 3068 en_US
dc.rights All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner. en_US
dc.subject High performance liquid chromatography en_US
dc.subject Oligomers en_US
dc.title Effect of oligomer chain length and substituent configuration on the enantioselectivity of a maltooligosaccharide chiral stationary phrase for HPLC en_US
dc.type Thesis en_US
dc.type.dcmi Text en_US

Item File(s)

Description Files Size Format View
Restricted for viewing only uhm_phd_9506237_r.pdf 2.044Mb PDF View/Open
For UH users only uhm_phd_9506237_uh.pdf 2.015Mb PDF View/Open

This item appears in the following Collection(s)

Show simple item record


Advanced Search


My Account