基于多壁碳纳米管修饰电极的磺胺的电化学检测

Electrochemical detection of sulfanilamide based on multiwall carbon nanotubes modified glassy carbon electrode

运用线性扫描伏安法(LSV)研究了磺胺(SA)在多壁碳纳米管修饰电极(MWNTs/GCE)上的电化学行为,探讨并确定了修饰体积和浓度、支持基质种类、最佳pH值、富集电位和时间等磺胺的最佳检测条件。结果表明,在pH=8.0的Na2HPO4-NaH2PO4缓冲体系中,磺胺在多壁碳纳米管修饰电极上检测到一个不可逆的氧化峰,且在1.0×10-5~2.0×10-4mol/L浓度范围内,磺胺氧化峰电流与其浓度呈现良好的线性关系,线性回归方程为Ip(μA)=0.493 6×C(μmol/L)+9.984 1,相关系数为R=0.996 3,检测下限为8.0×10-6mol/L,平行测定的相对误差(RSD)小于1.463%(n=8),样品平均加标回收率为99.21%~100.93%。

The electrochemical behavior of sulfanilamide（ SA） was studied with the multiwall carbon nanotubes modified glassy carbon electrode（ MWNTs/GCE） by using linear sweep voltammetry（ LSV）,and the best optimal determination conditions of sulfanilamide were investigated including MWNTs modified volume and concentration,supporting electrolyte type,best pH value,preconcentration potential and time,etc. The result showed that in Na2HPO4-Na H2PO4 buffer system at pH value of 8. 0,an irreversible oxidation peak of sulfanilamide was detected on the modified electrode,and between 1. 0 × 10-5and 2. 0 × 10-4mol/L,there is a good linear relation between the oxidation peak current and sulfanilamide concentration,the regression equation with the correlation coefficient of 0. 996 3 was Ip（ μA） = 0. 493 6 × C（ μmol/L） ＋ 9. 984 1. The detection limit was 8. 0 × 10-6mol/L. The relative standard deviation（ RSD） of successive determinations was less than 1. 463%（ n = 8）. The average recovery of the sample was 99. 21% ~ 100. 93%.