DA和AA在CPB现场修饰碳糊电极上的电化学行为及电分析方法  

Electrochemical Behavior of Dopamine and Ascorbic acid at CPB/CPE and Its Application

作　　者：韩晓霞[1] 高作宁[1] 

机构地区：[1]宁夏大学能源化工重点实验室化学化工学院,银川750021

出　　处：《应用化学》2007年第7期770-773,共4页Chinese Journal of Applied Chemistry

基　　金：教育部科学研究重点项目(204149);宁夏高等学校科学研究基金项目(2006)资助

摘　　要：研究了多巴胺（Dopamine,DA）和抗坏血酸（Ascorbic acid,AA）在裸碳糊电极（Carbon Paste Electrode,CPE）和溴化十六烷基吡啶（Cetylpyrid bromide,CPB）现场修饰碳糊电极（CPB/CPE）上的电化学行为。与CPE相比,DA在CPB/CPE上与CPB产生了静电排斥作用,氧化峰电流减小,氧化峰电位正移;AA和CPB产生了静电吸引作用,氧化峰电流增大,氧化峰电位负移。循环伏安法研究表明,在DA和AA共存体系中,DA和AA的氧化峰电位相差约340 mV,以此建立了DA和AA的电化学同时测定方法。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在1.0×10^-5-5.0×10^-3mol/L的范围内呈良好的线性关系。本方法也可用于DA和AA共存体系中选择性测定DA。在100倍AA共存时DA的检出限为2.0×10^-6mol/L,CPB修饰碳糊电极直接用于市售针剂中DA含量的测定,所得结果令人满意。The electrochemical behavior of Dopamine （DA） and Ascorbic Acid （AA） at both carbon paste electrode（CPE） and in situ CPB modified carbon paste electrode （CPB/CPE） was investigated. On the surface of CPB/CPE electrode, owing to the electrostatic interaction of CPB and negatively charged AA, the oxidation peak potential shifted more negatively and the peak current increased. On the other hand, the positively charged DA was repelled from the electrode surface and the oxidation peak potential shifted more positively and the peak current decreased. The anodic potential difference between AA and DA is about 340 mV, and AA does not interfere with the electroanalytical determination of DA at CPB/CPE. Linear calibration curves were obtained for both AA and DA in a concentration range of 1.0×10^5 - 5.0 ×10^3 moL/L. The detection limit of DA in the presence of AA 100-fold that of DA was 2.0×10^6 mol/L. The CPB/CPE was used to determine DA in dopamine injection samples spiked with AA.

关 键 词：多巴胺 抗坏血酸 溴化十六烷基吡啶 碳糊电极 现场修饰 

分 类 号：O657.1[理学—分析化学]