聚色氨酸修饰玻碳电极测定动物性食品中己烯雌酚

马心英; 吕惠萍; 王宜磊

doi:10.13386/j.issn1002-0306.2017.14.003

聚色氨酸修饰玻碳电极测定动物性食品中己烯雌酚

Determination of diethylstilbestrol in animal food by a poly (tryptophan) modified glassy carbon electrode

摘要

摘要: 用循环伏安法制备了聚色氨酸修饰玻碳电极。研究了己烯雌酚在聚色氨酸修饰电极上的电化学行为,建立了一种直接测定动物性食品中己烯雌酚含量的新方法。实验结果表明:在p H=5.0的磷酸盐缓冲溶液体系中,己烯雌酚在聚色氨酸修饰玻碳电极上于-0.2⁰.8 V范围内出现一对可逆的氧化还原峰,与裸玻碳电极相比较,聚色氨酸修饰电极对己烯雌酚的电化学反应具有促进作用。己烯雌酚浓度在5.00×10^-8¹.00×10^-6mol/L范围内与其氧化峰电流成正比,检出限为2.00×10^-9mol/L,对己烯雌酚溶液平行测定6次的RSD为2.4%。该修饰电极具有良好的灵敏度、选择性和稳定性,可用于牛肉、鱼肉及奶粉中己烯雌酚含量的测定,回收率为96.0%¹02.3%,结果满意,方法具有实用价值。

Abstract: A poly ( tryptophan) modified glassy carbon electrode ( PTRY/GCE) was prepared by cyclic voltammetry. The electrochemical behavior of diethylstilbestrol ( DES) at the fabricated electrode was studied.A new method for the determination of DES in animal food was established.The experimental results showed that in p H5.0 phosphate buffer solution ( PBS) system, DES appeared a pair of quasi redox peaks in the potential range of-0.2 to 0.8 V on the PTRY/GCE. The modified electrode showed a catalytic effect to the electrochemical reaction of DES.The oxidation peak current was proportional the concentratio of DES with a linear range of 5.00 × 10^-8 to 1.00 × 10^-6 mol/L and a limit of detection was 2.00 × 10^-9mol/L. The RSD for 6paralled determinations was 2.4%.The poly ( tryptophan) modified glassy carbon electrode had good sensitivity, selectivity, and stability.The method could be applied to the determination of DES in beef, fish and milk powder with recoveries of 96.0% ¹02.3%.The results were satisfactory, and the method had practical value.