الفهرس 
summaryOnly 14 pages are availabe for public view
 |  | from | 318 |  |  |
| | | from | 318 | | |
Abstract
Xanthine, hypoxanthine, 3-methylxanthine and 7xanthine are compounds of great biological importance. Their redox behaviour is important from both an analytical and mechanistic view. Therefore, the adsorption and association in adsorbed state of these derivatives in absence and presence of some divalent metal ions at the mercury/solution interface and the influence of methyl group position on the stacking interaction between vertically oriented molecules were studied at various pH values. The adsorption behaviour was followed by phase-sensitive a.c voltammetric and cyclic voltammetric measurements. In the present work the cathodic adsorptive stripping (CAdS) technique using differential pulse voltammetry is applied for the determination of the investigated compounds. Its application is based on the ability of these derivatives being determined to accumulate as Hg(lI)-xanthines or Cu(II)-Xanthines chelates at the static mercury surface. The effective preconcentration associated with the adsorption of Cu(II)-xanthate complex on the HMDE results in a highly sensitive method for trace determination of these compounds in presence of Cu(II).
In what follow, a brief description of the different chapters reported in this Thesis is given:
1. In Chapter L a general literature survey on the previous electrochemical and electro analytical studies on some purine and pyrimidine compounds is reviewed.