Electrochemical determination of 8-oxoguanine in the presence of uric acid.
The electrochemical oxidation of 8-oxoguanine (8-oxoG) in the presence of uric acid (UA) was studied by differential pulse voltammetry over a wide pH range (1-12). The results showed that both compounds follow a pH-dependent oxidation mechanism that involves two electrons and two protons corresponding to reversible charge transfer reactions. The difference between the peak potential for the oxidation of each analyte was found to be always less than 100 mV over the whole pH range, the separation being greater in the pH interval 4-7. In mixtures of both analytes, pH 6 was shown to be the best for 8-oxoG determination in the presence of uric acid, since the peak current is higher and a greater peak separation is achieved.
Rebelo
Isabel
I
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal.
Piedade
José António P
JA
Oliveira Brett
Ana Maria
AM
D045424:Complex Mixtures / Q000032:analysis / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D006147:Guanine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D014527:Uric Acid / Q000032:analysis* / Q000737:chemistry*; D016482:Urinalysis / Q000379:methods*
D045424:Complex Mixtures; D014527:Uric Acid; C024829:8-hydroxyguanine; D006147:Guanine