Edge plane pyrolytic graphite electrodes for halide detection in aqueous solutions

The behavior of chloride, bromide and iodide at edge plane pyrolytic graphite electrodes has been explored in aqueous acid solutions. The voltammetric response in each case has been compared with that of basal plane pyrolytic graphite, glassy carbon and boron-doped diamond. The electrochemical oxidation of chloride is found to only occur on boron-doped diamond while the electrochemical reversibility for the oxidation of bromide on edge plane pyrolytic graphite is similar to that seen at glassy carbon whilst being superior to basal plane pyrolytic graphite and boron-doped diamond. In the case of iodide oxidation, edge plane and basal plane pyrolytic graphite and glassy carbon display similar electrode kinetics but are all superior to boron-doped diamond. The analytical possibilities were examined using the edge plane pyrolytic graphite electrode for both iodide and bromine where is was found that, based on cyclic voltammetry, detection limits in the order of 10(-6) M are possible.