APPLICATIONS OF ZMEs IN ELECTROANALYSIS OF ORGANICS

Abstract

In this paper, the role of Ag/Cu-modified zeolite in order to improve the electroanalytical performances of zeolite-modified electrodes (ZMEs) to detect organic pollutants is discussed. Two types of ZMEs, i.e., Ag/Cu-modified zeolite-expanded graphiteepoxy composite electrodes are discussed in comparison with expanded graphite-epoxy composite electrode. Function of the electroactivity of target species, two major characteristics of the zeolite was exploited, e.g., sorption capacity and catalytic properties of Cu/Ag-modified zeolite. Thus, for the electrochemical determination of 4-chlorophenol, the sensitivity was improved by applying a preconcentration step before electrochemical quantification. Ag-modified zeolite-expanded graphitecomposite electrode exhibited both the electrocatalytic and preconcentration effect toward urea oxidation that led to its determination in aqueous solution, and Cu-modified zeolite-expanded graphite-composite electrode allowed the electrochemical determination of glucose. These modified electrodes impart both catalytic properties to the electrode surface for the electrooxidation of organics and/or selective sorption capacity to preconcentrate the target analyte prior its sensitive electrochemical detection.