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ELECTROCHEMICAL STUDIES OF SOME BIOLOGICALLY ACTIVE COMPOUNDS USING GRAPHITE PASTE ELECTRODE

Syed, Azhar Ali (1995) ELECTROCHEMICAL STUDIES OF SOME BIOLOGICALLY ACTIVE COMPOUNDS USING GRAPHITE PASTE ELECTRODE. PhD thesis, University of Karachi, Karachi.

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Abstract

Electrochemical study of some biologically active compounds (a-methylodopa, bendrofluazide, furosemide, hydrochlorothiazide, and reserpine) has been done at a carbon paste electrode vs. Ag/AgCI reference electrode in various supporting electrolytes. Cyclic voltammetry was performed to determine qualitative and quantitative characteristics of these compounds. The compound a-methyldopa showed a quasi-reversible electron transfer reaction. The values of transfer coefficient a or B were determined. In a very few systems, the value of Ko the standard heterogeneous rate constant were obrained form Ep vs. values. The larger values of Ep were obtained due to the use of unmodified carbon paste electrode which decreases the rate of electron transfer at the surface of the test electrode. Other compounds like bendrofluazide, furosemide, hydrochlorothiazde, and reserpine showed a totally irreversible electron transfer at the unmodified carbon paste electrode. The values of transfer coefficients, B were determined by using different equations. The quantitative studies with cyclic voltammetry revealed that the use of a carbon paste electrode can be used to quantify these compounds (a-methyldopa 4.2X10-3 to 8.4X10-6 M, bendrofluazide 2.37X10-5 to 4.28X10-6 M, furosemidel 2X10-5 to 2.42X10-4 M hydrochlorothiazide 3.0X10-4 to 1.0X10-5M, and reserpine 1.41X10-5 to 2.54X10-6 M). This method can be applied in the pharmaceutical quality control assays of these compounds which has not been reported earlier.

Item Type:Thesis (PhD)
Uncontrolled Keywords:graphite paste electrode, a-methylodopa, bendrofluazide, furosemide, hydrochlorothiazide, reserpine, cyclic voltammetry, antihypertensive compounds
Subjects:Physical Sciences (f) > Chemistry(f2)
ID Code:716
Deposited By:Mr. Muhammad Asif
Deposited On:27 Sep 2006
Last Modified:04 Oct 2007 21:02

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