Abstract A glassy carbon electrode modified with magnetite nanoparticles dispersed in chitosan was employed as electrochemical detector for the determination of parathion in food samples by cathodic square-wave voltammetry. The modified electrode surface was characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Under optimized experimental conditions, the square-wave voltammograms for parathion obtained with the proposed modified electrode exhibited a well-defined peak at −0.59 V, corresponding to the reduction of the nitro group to the hydroxylamine group. The resultant cathodic peak current was linear for parathion concentrations in the range of 0.34 to 4.46 μmol L−1 (r = 0.997). The limits of detection and quantification were 0.187 and 0.567 μmol L−1, respectively. The novel detector was successfully employed for the analysis of parathion in five food samples (carrot, orange, tomato, lettuce and rice) using the standard addition method. The results were statistically compared with data obtained using the UV–vis technique.

中文翻译：

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用于通过阴极方波伏安法非酶法检测内分泌干扰物对硫磷的磁铁矿纳米颗粒/壳聚糖修饰的玻碳电极

摘要 采用分散在壳聚糖中的磁铁矿纳米颗粒修饰的玻碳电极作为电化学检测器，采用阴极方波伏安法测定食品样品中的对硫磷。通过扫描电子显微镜、循环伏安法和电化学阻抗谱对改性电极表面进行表征。在优化的实验条件下，使用所提出的修饰电极获得的对硫磷方波伏安图在 -0.59 V 处显示出明确的峰，对应于硝基还原为羟胺基团。对硫磷浓度范围为 0.34 至 4.46 μmol L-1 (r = 0.997) 时，所得阴极峰值电流呈线性。检测限和定量限分别为 0.187 和 0.567 μmol L-1。该新型检测器已成功用于使用标准添加方法分析五种食品样品（胡萝卜、橙子、番茄、生菜和大米）中的对硫磷。将结果与使用 UV-vis 技术获得的数据进行统计比较。