聚脯氨酸修饰电极循环伏安法选择性测定去甲肾上腺素

目的 建立聚脯氨酸修饰电极测定去甲肾上腺素的新方法,并有效排除肾上腺素与抗坏血酸干扰.方法 在pH 9.0的磷酸盐缓冲溶液中.用循环伏安法制备了聚脯氨酸修饰电极,研究去甲肾上腺索在聚合物薄膜上的电化学行为,建立测定去甲肾上腺素的电化学分析新方法.结果 在pH 7.0的磷酸盐缓冲溶液中,去甲肾上腺素在修饰电极上呈现一对灵敏的氧化还原峰,利用循环伏安法测定其还原峰电流可排除肾上腺素与抗坏血酸干扰.去甲肾上腺素检测的线性范围是7.0×10-7～1.1×10-4mol/L:检出限为6.0×10-8mol/L.结论 该修饰电极具有良好的灵敏度、选择性和稳定性,用于药剂样品分析,结果满意.

Selective determination of norepinephrine by a cyclic voltammetric method using poly-proline-modified electrodes

OBJECTIVE: To establish a new method for determining norepinephrine (NE) in the presence of epinephrine and ascorbic acid using proline-modified glassy carbon electrode (GCE). METHODS: In phosphate buffer solution (pH 9.0), the poly-proline-modified electrode was prepared by cyclic voltammetry method. The voltammetric behavior of NE on poly(proline) film were analyzed to establish a electrochemical analysis method for determination of NE on the modified electrode. RESULTS: In PBS (pH 7.0), a couple of redox peaks of NE was observed on the modified electrode. The modified electrode was used to determine NE in a excess of epinephrine (EP) and ascorbic acid (AA) by reduction peak current of cyclic voltammetry. The reduction peak currents were in linear relationship with the NE concentrations within the range of 7.0x10(-7) to 1.1x10(-4) mol/L, with the detection limit of 6.0x10(-8) mol/L. CONCLUSION: The modified electrode shows good sensitivity, selectivity, and stability for NE determination, and is well applicable for analysis of injection solution samples.