Micelle-mediated method for simultaneous determination of ascorbic acid and uric acid by differential pulse voltammetry

Journal of the Brazilian Chemical Society

Kubota, Lauro T.¹  Universidade Federal de Alfenas, Alfenas, Brazil¹  Universidade Estadual de Campinas, Campinas, Brazil¹  Tarley, César R. T.¹  Reis, Alaécio P. dos¹ 

关键词: uric acid;    ascorbic acid;    differential pulse voltammetry;    cationic surfactant;    micelles;   

DOI  :  10.1590/S0103-50532008000800017

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

The present work describes an analytical methodology for simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry employing the cationic surfactant, cetylpyridinium chloride. Differential pulse voltammetry measurements revealed that the cationic micellar media may separate the oxidation peak potentials of AA and UA present in the same solution by about 282 mV, which is enough to determine both species simultaneously. As in pH 7.0 the AA is more ionized than UA, its electrostatic attraction towards the cationic micelles formed onto the surface of glassy carbon electrode is higher, therefore, promoting a decrease in the overpotential and increasing the electron transfer rate. Calibration curves to AA and UA in the concentration range from 4.70 up to 220 µmol L-1 and 0.50 up to 110 µmol L-1 were built. The proposed methodology was applied for the simultaneous determination of AA and UA in human urine samples.

【 授权许可】

Unknown