利用3-噻吩丙二酸修饰玻碳电极快速检测苏丹红

Fast Determination of Sudan Dyes Using Poly(3-Thiophenemalonic Acid) Modified Glassy Carbon Electrode

利用电化学聚合法制备3-噻吩丙二酸(3-TPA)修饰玻碳电极。利用循环伏安法研究苏丹红在3-TPA修饰玻碳电极上的电化学行为,得出预富集时间、pH值、扫描速率及扫描范围因素对该修饰电极检测苏丹红的影响。在最佳条件下,利用差分脉冲伏安法得出在2.0×10-5～1.3×10-3mol/L浓度范围内苏丹红Ⅰ响应电流与其浓度对数呈良好的线性关系,相关系数r=0.996,检测限为4.8×10-6mol/L。辣椒粉、辣椒酱加标回收率分别为99.9%和99.4%,相对标准偏差(n=3)分别为0.25%和0.21%。另外,对苏丹红Ⅰ氧化还原机理进行了初步的探讨。

Poly（3-thiophenemalonic acid）（3-TPA） modified glassy carbon electrode was prepared by electrochemical polymerization, and the electrochemical behavior of Sudan dyes was studied on the modified electrode using cyclic voltammetric method. The effects of preconcentration time, pH value of buffer solution and scan rate and range were also studied using differential pulse voltammetry in order to determine their optimal values. Under the optimize conditions, the modified electrode showed a linear response over the SudanⅠconcentration range from 2.0 × 10^-5 to 1.3 × 10^-3 mol/L, with a correlation coefficient of 0.996. The method detection limit was 4.8 × 10^-6 mol/L. The average recoveries （3 replicates） of Sudan Ⅰ in spiked pepper powder and sauce samples were 99.9% and 99.4%, and the relative standard deviations were 0.25% and 0.21%, respectively. Moreover, the oxidation-reduction mechanism of Sudan Ⅰ was preliminarily discussed.