Selective electronalysis of peracetic acid in the presence of a large excess of H2O2 at Au(111)-like gold electrode.
Peracetic acid (PAA) has been selectively electroanalyzed in the presence of a large excess of hydrogen peroxide (H(2)O(2)), about 500 fold that of PAA, using Au (111)-like gold electrode in acetate buffer solutions of pH 5.4. Au(111)-like gold electrode was prepared by a controlled reductive desorption of a previously assembled thiol, typically cysteine, monolayer onto the polycrystalline gold (poly-Au) electrode. Cysteine molecules were selectively removed from the Au(111) facets of the poly-Au electrode, keeping the other two facets (i.e., Au(110) and Au(100)) under the protection of the adsorbed cysteine. It has been found that Au(111)-like gold electrode positively shifts the reduction peak of PAA, while, fortunately, shifts the reduction peak of H(2)O(2) negatively, achieving a large potential separation (around 750 mV) between the two reduction peaks as compared with that (around 450 mV) obtained at the poly-Au electrode. This large potential separation between the two reduction peaks enabled the analysis of PAA in the presence of a large excess of H(2)O(2). In addition, the positive shift of the reduction peak of PAA gives the present method a high immunity against the interference of the dissolved oxygen.
Department of Chemistry, Faculty of Science, Cairo University, Egypt. mawad70@yahoo.com
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D000327:Adsorption; D002623:Chemistry Techniques, Analytical; D003545:Cysteine / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010463:Peracetic Acid / Q000032:analysis*; D012680:Sensitivity and Specificity; D013499:Surface Properties
D006046:Gold; D006861:Hydrogen Peroxide; D010463:Peracetic Acid; D003545:Cysteine; D010100:Oxygen