Abstract

Electroanalysis of ethanol at a Pt-Pb(ad) and Pt-Pb(ad)-I(ad) adatomelectrodes

Author(s): Wojdan W.Qaddumi, Mohammed Khair Hourani

The hyperrecativity of platinum electrodes renders these electrodes useless for routine electrochemical analysis. The present work utilizes modification of polycrystalline platinum with Pb for enhancing the reactivity of Pt electrode towards oxidation of ethanol and I atoms for suppression of its liability towards molecular adsorption. The notion of enhancement of oxidation of ethanol was fully tested by cyclic voltammetry. For better sensitivity, ethanol was analyzed at the Pt-Pb(ad)-I(ad) electrode by differential pulse voltammetry. The electrode showed a linear response for ethanol within a concentration range of 5x10-6M to 4x10-5M with a minimum detectability of 1.1x10-7mol l-1 (0.11 ppmethanol). The accuracy of analysis of ethanol at the Pt-Pb(ad)-I(ad) electrode was tested by comparing it with a spectrometric analysis of ethanol.