In this work we report electrocatalytic oxidation and flow injection analysis of tuberculostatic drug isoniazid (INZ) based on a disposable and unmodified screen printed carbon electrode (SPCE). Instead of using chemically modified electrode to increase the sensitivity at low overpotential, the same purpose can be achieved simply by preanodization of a bare SPCE in a suitable electrolyte medium. Surface characterization of the as‐preanodized electrode by X‐ray photoelectron spectroscopy and Raman spectroscopy indicate that both oxygen functionalities and edge/defect sites effectively assist the INZ oxidation. Flow injection analysis extends its applicability with a wide linear range up to 1 mM and an enhanced sensitivity of 100 nA μM⁻¹ with a low detection limit of 2.7 nM (S/N=3). These good analytical features accomplished with disposable and economical devices could make possible the implementation of this methodology for INZ on‐line monitoring in pharmaceuticals.

中文翻译：

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在中性pH下使用未经修饰的丝网印刷碳电极对异烟肼药物进行电催化氧化和流动注射分析

在这项工作中，我们报告了基于一次性和未修饰的丝网印刷碳电极（SPCE）的抗结核药物异烟肼（INZ）的电催化氧化和流动注射分析。代替使用化学修饰的电极来提高低过电势下的灵敏度，可以通过在合适的电解质介质中对裸露的SPCE进行预阳极氧化来简单地达到相同的目的。通过X射线光电子能谱和拉曼光谱对预阳极氧化的电极进行表面表征表明，氧官能度和边缘/缺陷位点都可以有效地帮助INZ氧化。流动注射分析以高达1 mM的宽线性范围和100 nAμM ^- 1的增强的灵敏度扩展了其适用性检测限低至2.7 nM（S / N = 3）。利用一次性且经济的设备实现的这些良好的分析功能可以使这种方法在药物中INZ在线监测的实施成为可能。