The Influencing Mechanism of Acidity on the Oxidation Peak Currents of Uric Acid and Ascorbic Acid at the PACPE by Cyclic Voltammetry |
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| Authors: | Li Jing Shangguan En‐bo Li Quan‐min |
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| Affiliation: | School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007, PR China |
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| Abstract: | In this paper, a pre‐anodized carbon paste electrode (PACPE) is fabricated by a simple electrochemical pretreatment method, which can be used for the simultaneous determination of uric acid (UA) and ascorbic acid (AA). The influencing mechanism of the acidity on the size of oxidation peak current (ip,a) of UA and AA is discussed in detail. According to the results, in different pH conditions, the intensity of hydrogen bonding between UA, AA and the surface of PACPE, the degree of reduction reaction at the auxiliary electrode, and the structural configurations of UA and AA with different species in reaction system have evident influence on the size of oxidation peak current. In pH 7.00 phosphate buffer solution, the calibration curves for UA and AA are obtained in the range of 5.0 x 10‐7–5.0 x 10‐5 mol/L and 3.0 x 10‐5–5.0 x 10‐3 mol/L, respectively. The detection limits for UA and AA are found to be 2.0 x 10‐8 mol/L and 1.2 x 10‐6 mol/L, respectively. This proposed method has been successfully applied to determine UA and AA in human urine simultaneously with satisfactory results. |
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| Keywords: | Pre‐anodized carbon paste electrode Cyclic voltammetry Uric acid Ascorbic acid |
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