铋膜修饰电极测定蕃茄制品中苏丹红Ⅰ

Determination of Sudan Ⅰ in Tomato Catchup with Bismuth-film Modified Electrode

采用预镀法将Bi 3+还原成金属铋固定在玻碳电极表面,制成稳定的铋膜修饰玻碳电极(BFE),利用循环伏安法(CV)、方波伏安法(SWV)研究了苏丹红Ⅰ在该电极上的电化学行为。实验结果表明,在pH=2.0的B-R缓冲溶液、乙醇溶液中,苏丹红Ⅰ在-380mV附近产生一灵敏的还原峰,在优化的实验条件下,苏丹红Ⅰ的峰电流iP与其浓度在1.0×10-7～1.6×10-5 mol/L范围内有良好的线性关系,R=0.9987,检出限为3.3×10-8 mol/L。铋膜电极无毒、无污染,灵敏度高,为检测苏丹红Ⅰ提供了一种安全有效的新方法。

Bismuth-film electrode（BFE） was prepared by ex situ depositing bismuth onto GCE for the detection of Sudan I. The sufficiently wide negative potential window available made the BFE a potentially suitable electrode for application in the field of cathodic electrochemical detection of Sudan I. The BFE showed similar or even better performance compared to mercury and bare electrode. Operational parameters, including the deposition potential and time of bismuth-film, pH of the assay solution and co-solvents have been optimized. Under the optimum experimental conditions, the cathodic voltammetric response was proportional to the concentration of Sudan Ⅰin the range from 1.0 × 10-7 to 1. 6 × 10-5 mol/L,with a correlation coefficient of 0. 9987. The detection limit was 3.3 × 10.8 mol/L. Due to the easy preparation and regeneration of BFE together with its good reproducibility and stability, the combination of the promising BFE and cathodic voltammetric performances opens new opportunities for fast,simple and sensitive analysis of Sudan I in samples.