聚亚甲基蓝修饰金电极对过量抗坏血酸存在下尿酸的测定  

Selective Determination of Uric Acid in the Presence of Excessive Ascorbic Acid at Polymethylene Blue Modified Gold Electrode

作　　者：马艳蓉[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,宁夏银川750021

出　　处：《分析测试学报》2008年第2期139-142,147,共5页Journal of Instrumental Analysis

基　　金：宁夏高等学校科学研究基金资助项目(200623)

摘　　要：研究了亚甲基蓝（MB）聚合物膜修饰金电极（PMB／Au）的电化学行为，通过电化学阻抗谱图对其进行了表征，并研究了抗坏血酸（AA）和尿酸（UA）在PMB／Au上的电化学行为。研究结果表明，在PBS水溶液中AA和UA在PMB／Au上的氧化峰电位均负移，峰电流增大，表明PMB／Au对AA和UA电化学氧化反应均产生了催化作用。微分脉冲伏安法（DPV）研究结果表明，在AA和UA共存体系中，AA和UA的氧化峰电位相差约430mV，以此建立了AA和UA的电化学选择性测定方法。在1．0mmol·L^-1 AA共存体系中UA氧化峰电流与其浓度在5．0×10^-6～8．0×10^-3mol·L^-1范围内呈良好的线性关系。在500倍AA共存时UA检出限为1．0μmol·L^-1，PMB／Au可直接应用于人体尿样中UA的测定，结果令人满意。The electrochemical properties of polymethylene blue （PMB）modified gold electrode （PMB/Au） were investigated by cyclic voltammetry and electrochemical impedance spectra（EIS）, the electrochemical behaviors of ascorbic acid （AA） and uric acid （UA） at PMB/Au were also studied. The experimental results showed that the anodic peak potential of AA and UA shifted negatively and that the anodic peak current increased at PMB/Au electrode more than at bare gold electrode. The anodic peak of UA could be separated from AA with 430 mV at PMB/Au electrode by differential pulse voltammetry（DPV） and AA did not interfere the measurement of UA. The catalytic oxidation peak current was linearly dependent on the UA concentration. The linear range of the calibration curve was 5.0×10^-6 -8.0×10^-3 mol·L^-1 with a correlation coefficient of 0. 998 7 in the presence of 1.0 mmol·L^-1 AA. The detection limit of UA was 1.0 μmol·L^-1 in the presence of 500 - fold AA. The method has been applied to the determination of UA concentration in human urine samples with satisfactory result.

关 键 词：抗坏血酸 尿酸 聚亚甲基蓝 修饰电极 

分 类 号：O657.15[理学—分析化学]