Modification of carbon paste electrode with Fe (Ⅲ) -clinoptilolite nano-particles for simultaneous voltammetric determination of acetaminophen and ascorbic acid

摘要

A novel carbon paste electrode (CPE) modified with Fe(Ⅲ)-exchanged clinoptilolite nano-particles (Fe(Ⅲ)-NClino/CPE) was constructed and used for simultaneous voltammetric (CV, SqWand chronoamperometry) determination of ascorbic acid and acetaminophen. Raw and modified zeolites were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The square wave peak current was linearly increased in the concentration ranges of 1.0 × 10~(-9)-1.0 × 10~(-2) mol L~(-1) for ascorbic acid and 1.0 × 10~(-10-) 1.0 × 10~(-2) mol L~(-1) for acetaminophen with detection limits of 1.8 × 10~(-9) mol L~(-1) and 9.9 × 10~(-10) mol L~(-1), respectively. The detection limits of 2.4 × 10~(-10) mol L~(-1) and 2.5 × 10~(-11) mol L~(-1) were also obtained for AA and AC in chronoamperometric measurements, respectively. The diffusion coefficients of 7.5 × 10~(-5) cm~2 s~(-1) and 2.4 × 10~(-5) cm~2 s~(-1) were respectively calculated for the oxidation of AC and AA by chronoamperometry. The proposed electrode exhibited high sensitivity and good stability, and would be valuable for the clinical assay of ascorbic acid and acetaminophen.