聚伊文思蓝膜修饰玻碳电极在抗坏血酸共存时测定去甲肾上腺素

Determination of norepinephrine in the presence of ascorbic acid with poly Evans Blue modified glassy carbon electrode

目的:研究聚伊文思蓝(Evans Blue)膜修饰玻碳电极对去甲肾上腺素(NE)和抗坏血酸(AA)的电化学行为,建立测定NE 含量的电化学分析新方法。方法:采用循环伏安法研究 NE 和 AA 在聚伊文思蓝膜修饰电极上的电化学行为,以差示脉冲伏安对 NE 的含量进行测定。结果:聚伊文思蓝膜修饰电极对 NE 和 AA 有显著的增敏和电分离作用,氧化峰电位差为282mV。在 pH 5.0的磷酸盐缓冲液中,氧化峰电流与 NE 浓度在5.0×10^(-7)～1.8×10^(-5)mol·L^(-1)范围内呈良好的线性关系,检测限为4.0×10^(-8)mol·L^(-1)。结论:该修饰电极在抗坏血酸共存时可测定 NE,有效消除其他组分对 NE 测定的干扰,已用于实际样品 NE 含量的测定,结果令人满意。

Objective： To study the electrochemical behavior of norepinephrine （NE） and ascorbic acid （AA） on the poly Evans Blue film modified electrode by cyclic vohammetry（CV） and establish a novel method for the determination of the content of NE. Method：The electrochemical behavior of NE and AA at the poly Evans Blue film modified electrode was studied by cyclic vohammetry while the content of NE was measured in differential pulse voham- metry （DPV）. Results： The modified electrode shows enhanced sensitivity and excellent electrochemical discrimination to NE and AA, the oxidation potential difference of NE and AA was about 282 mV. In pH 5.0 phosphate buffer solution, the relationship between oxidation peak current and the concentration of NE was linear in the range of 5.0 × 10^-7 - 1.8× 10^-5 mol· L^-1. The detection limit was 4. 0 ×10^-8 mol· L^-1. Conclusion： Norepinephrine could be determined in the presence of ascorbic acid and the interference of other components can be efficiently elimina- ted on the modified electrode. This method can be used for the determination of NE in real sample with satisfactory results.