聚伊文思蓝修饰电极对多巴胺和抗坏血酸的电分离及同时测定

Electrocatalytic Separation for Dopamine and Ascorbic Acid Using Poly-Evans Blue Modified Glassy Carbon Electrode and Simultaneous Determination

研究多巴胺（DA）和抗坏血酸（AA）在聚伊文思蓝（Evans Blue）修饰电极上的伏安行为,建立差示脉冲伏安测定法.在pH4.5磷酸盐缓冲液中,聚伊文思蓝修饰电极对DA和AA有显著的增敏和电分离作用.DA和AA氧化峰电流与浓度分别在1.0×10^-6 - 3.0×10^-5mol/L和5.0×10^-6-1.05×10^-4mol/L范围内呈良好的线性关系,检测限分别为2.5×10^-7mol/L和3.0×10^-7mol/L.当DA与AA共存时,由该修饰电极检测的二者氧化峰电位差达184 mV,故可同时测定DA和AA,并有效消除其它组分对DA测定的干扰,已用于实际样品中DA和AA含量的测定,结果令人满意.

Voltammetric behavior of the Dopamine （DA） and ascorbic acid （AA） at PolyEvans Blue modified electrode were studied and a novel method for determination of the content of DA and AA is established. In pH 4.5 phosphate buffer solution, the modified electrode shows enhanced sensitivity and excellent electrochemical discrimination to DA and AA. The relationship between oxidation peak current and the concentration of DA or AA is linear in the range of 1.0×10^-6 - 3.0×10^-5mol/L and 5.0×10^-6-1.05×10^-4molL, the detection limit has been estimated as 2.5× 10^ -7 mol/L and 3.0 × 10^ -7 mol/L, respectively. The oxidable potential difference of DA and AA was about 184 mV at Poly-Evans Blue modified electrode. So it is used to simultaneously determine the DA and AA without any interference. The interference of other components could be efficiently eliminated at the modified electrode, and this method can be used for determination of DA and AA in real sample with satisfactory results.