Publication Date

1984

Document Type

Dissertation/Thesis

First Advisor

Roston, Daryl A.

Degree Name

M.S. (Master of Science)

Department

Department of Chemistry

LCSH

Thioguanine||Liquid chromatography||Blood--Analysis||Electrochemistry

Abstract

A new detection system for the analysis of 6-thioguanine (6-TG) and 6-thioguanine riboside (6-TGR) in plasma samples has been investigated. The investigation began with a study of the electrochemistry of 6-TG and 6-TGR. First, cyclic voltammograms, were obtained for each compound. Second, hydrodynamic voltammograms were obtained. From these two voltammograms, the optimal working voltage of 1.00 volt vs. Ag/AgCl reference for oxidative thin-layer amperometry was noted. Another set of hydrodynamic voltammograms using a mercury electrode were obtained for 6-TG and 6-TGR. From these two voltammograms the detector potential of 0.20 volts vs. Ag/AgCl reference was noted as the working potential. After the optimal working potentials were obtained, linearity experiments were performed using three modes of detection: U.V. absorption, oxidative amperometry and mercury electrode detection of the sulfhydryl group. From a standard solution range of 1.0-200 ng, calibration curves for 6-TG and 6-TGR using all three modes of detection were obtained. Using the data from the calibration curves, regression analysis for both compounds was performed. Then using the Student's t-test at the 95% level, detection limits for both compounds using each detection mode were estimated. The U.V. absorption detection mode had the highest estimated detection limits: 0.91 ng for 6-TG and 0.94 ng for 6-TGR. The Au/Hg electrode had estimated detection limits of 49 pg for 6-TG and 73 pg for 6-TGR. Finally, oxidative amperometry produced estimated detection limits of 14 pg for 6-TG and 31 pg for 6-TGR. The two electrochemical detection modes produced estimated detection limits lower than any previously published. The feasibility of using electrochemical detection for the determination of 6-TG and 6-TGR in clinical samples was shown by comparing plasma chromatograms observed with U.V. absorption, oxidative electrochemical and Au/Hg detection.

Comments

Bibliography : pages 55-56.

Extent

viii, 56 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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