Simultaneous determination of ascorbic acid and acetaminophen at the pre-anodized inlaying ultrathin carbon paste electrode

Abstract

A pre-anodized inlaying ultrathin carbon paste electrode (PAIUCPE) was constructed using simple and fast electrochemical pretreatment for the simultaneous determination of ascorbic acid (AA) and acetaminophen (ACOP). The effect of pH on peak current and peak potential for the oxidation of AA and ACOP was discussed in detail. The results showed that the size of i_p of AA and ACOP was closely related to the degree of oxygen reduction reaction at the auxiliary electrode. In pH 5.00 phosphate buffer solution, a linear relationship between oxidation peak current and concentration of AA and ACOP was obtained in the range of 1.0 × 10⁻⁵ to 1.5 × 10⁻³ mol L⁻¹ and 3.0 × 10⁻⁷ to 2.0 × 10⁻⁴ mol L⁻¹, and the detection limits were estimated to be 3.10 × 10⁻⁷ mol L⁻¹ and 2.28 × 10⁻⁸ mol L⁻¹, respectively. The constructed electrode exhibited excellent reproducibility and stability. Moreover, this method was employed to determine AA and ACOP in Vitamin C Yinqiao Tablets with satisfactory results.