In this study, the first application of a capillary zone electrophoresis-electrochemical detection (CE-ECD) method for concurrent determination of hydrogen peroxide (H2O2) and ascorbic acid (AA), was developed using the Pt nanoparticles (PtNPs) modified Pt micro-disk electrode (PtME). The electrocatalytic activity of the modified electrode for H2O2 and AA was characterized by cyclic voltammetry. Under optimized experimental conditions, highly linear calibration plots were observed for both H2O2 and AA, with concentration linear ranges of 0.8 μM to 0.8 mM and 1.0 μM to 0.8 mM. Detection limits of 0.2 μM H2O2 and 0.5 μM AA were determined on the basis of the signal-to-noise characteristics (S/N=3) of an electropherogram. Compared with the unmodified PtME, the sensitivity was promoted in that PtNPs/PtME provided an increased effective electrode surface and high catalytic activity toward H2O2 and AA. Using this method, the added H2O2 and AA in Mizone, a kind of functional drink, were detected, and the concentration of AA was found to be 2.33 mM (n=3). The recovery rates were 95.3 % for H2O2 and 98.7 % for AA. The novel approach provided a wide linear range, low detection limit, good reproducibility and stability. It will provide a new insight into the balance of reactive oxygen species and antioxidant in biological systems.

中文翻译：

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铂纳米颗粒修饰微盘电极毛细管电泳同时测定过氧化氢和抗坏血酸

在这项研究中，首次应用毛细管区带电泳-电化学检测 (CE-ECD) 方法同时测定过氧化氢 (H2O2) 和抗坏血酸 (AA)，使用 Pt 纳米粒子 (PtNPs) 修饰的 Pt 微圆盘电极（PtME）。通过循环伏安法表征修饰电极对 H2O2 和 AA 的电催化活性。在优化的实验条件下，观察到 H2O2 和 AA 的高度线性校准图，浓度线性范围为 0.8 μM 至 0.8 mM 和 1.0 μM 至 0.8 mM。0.2 μM H2O2 和 0.5 μMA AA 的检测限是根据电泳图的信噪比 (S/N=3) 确定的。与未修饰的 PtME 相比，由于 PtNPs/PtME 提供了增加的有效电极表面和对 H2O2 和 AA 的高催化活性，因此提高了灵敏度。使用该方法检测功能性饮料Mizone中添加的H2O2和AA，AA浓度为2.33mM（n=3）。H2O2 的回收率为 95.3%，AA 的回收率为 98.7%。这种新方法提供了宽的线性范围、低检测限、良好的重现性和稳定性。它将为生物系统中活性氧和抗氧化剂的平衡提供新的见解。这种新方法提供了宽的线性范围、低检测限、良好的重现性和稳定性。它将为生物系统中活性氧和抗氧化剂的平衡提供新的见解。这种新方法提供了宽的线性范围、低检测限、良好的重现性和稳定性。它将为生物系统中活性氧和抗氧化剂的平衡提供新的见解。