多巴胺及抗坏血酸在CTAB/CS复合物膜修饰电极上的电化学行为及其测定

Electrochemical behavior and simultaneous determination of dopamine and ascorbic acid at cetyl trimethyl ammonium bromide/chitosan modified electrode

制备了十六烷基三甲基溴化铵(CTAB)/壳聚糖(CS)复合物膜修饰电极,研究了多巴胺(DA)和抗坏血酸(AA)在该修饰电极以及裸电极上的电化学行为。循环伏安法研究表明,CTAB与带负电荷AA之间的静电作用使AA的氧化过电位降低,DA和AA两者的峰电位差达360 mV,使得DA和AA重叠氧化峰得以分离。以此建立了同时测定DA和AA的电化学方法。微分脉冲伏安法研究结果表明,DA和AA氧化峰电流和其相应浓度分别在1×10^(-5)～2.8×10^(-3) mol/L和5×10^(-6)～6×10^(-4) mol/L的范围内呈良好的线性关系。应用该方法对DA和AA进行了选择性测定研究,取得良好结果。

Cetyl trimethyl ammonium bromide(CTAB)/chitosan hybrid composite film modified electrode was fabricated simply.Electrochemical behavior of dopamine(DA) and ascorbic acid(AA) was investigated at the modified electrode and bare electrode.According to results of cyclic voltmmetry,the oxidation over potential of AA was lowered owing to the electrostatic interaction of CPB and negatively charged AA,and the potential difference of DA and AA was about 360 mV, indicating the common overlapped oxidation peaks of AA and DA can be separated completely.And electrochemical method for simultaneous determination of DA and AA was set up.Shown by the results of differential pulse voltmmetry,it has a good linearity of 1×10^(-5)～2.8×10^(-3) mol/L and 5×10^(-6)～6×10^(-4) mol/L for DA and AA,respectively.Furthermore,selective determination of DA or AA was also investigated using this electrochemical method with pleasing results.