Nafion-离子液体-修饰碳糊电极在抗坏血酸和尿酸存在下选择性测定多巴胺  

A nafion/ionic liquid/modified carbon paste electrode for selective detection of dopamine in the presence of ascorbic acid and uric acid

作　　者：张亚[1,2] 张宏芳[1] 郑建斌[1] 

机构地区：[1]西北大学分析科学研究所,西安710069 [2]榆林学院化学与化学工程学院,榆林719000

出　　处：《分析试验室》2008年第12期34-37,共4页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学基金(20675062);陕西省自然科学基金(2004B20)项目资助

摘　　要：用Nation和亲水性离子液体溴化1-辛基-3-甲基咪唑（[OMIM]Br）作修饰剂制作了Nation．离子液体．修饰碳糊电极；在0．1mol／L磷酸盐缓冲溶液（pH7．40）中，用循环伏安法（Cv）和方波伏安法（SWV）研究了多巴胺在该修饰电极上的电化学行为，建立了抗坏血酸和尿酸存在下选择性测定多巴胺的新方法。研究表明，该修饰电极降低了多巴胺氧化、还原反应的过电位，增大了其氧化、还原反应的峰电流，而抗坏血酸和尿酸在该修饰电极上无响应；在方波伏安曲线上，多巴胺的氧化电流与其浓度在3．0×10^-8～2．0×10^-6umol／L范围内呈线性关系，检出限为1．0×10^-8mol／L。该法可用于注射液和模拟生物样品中多巴胺的测定。A carbon paste electrode modified with nation and hydrophilic ionic liquid 1-octyl-3-methylimidazolium bromide （Nafion/IL/CPE） was fabricated. In 0.1 mol/L phosphate buffer solution （pH 7.40）, cyclic voltammetry and square wave voltammetry were used to investigate the electrochemical behavior of dopamine （DA） at the modified electrode and a new method for selective detection of dopamine in the presence of ascorbic acid and uric acid was established. As a result, an improved response of DA at the modified electrode was observed with reduction of overpotentials and increase of peak current, while ascorbic acid and uric acid had no response at this electrode. Under the optimal conditions, the oxidation peak current on square wave voltammogranls increases linearly with the concentration of DA in the range of 3.0 × 10^-8 - 2.0 × 10^-6 mol/L with a detection limit of 1.0 × 10^-8 mol/L. Satisfactory results are achieved when detecting DA in injections and simulated biology samples.

关 键 词：伏安法 NATION 离子液体 碳糊电极 催化作用 多巴胺 

分 类 号：O657.1[理学—分析化学]