L-半胱氨酸自组装修饰金电极-不可逆双安培测定阿魏酸  

Determination of Ferulic Acid Based on the L-Cysteine Self-assembled Modified Gold Electrode Coupling Irreversible Biamperometry

作　　者：李利军[1] 喻来波[2] 陈其锋[2] 程昊[1] 吴峰敏[2] 吴健玲[2] 孔红星[1] 

机构地区：[1]广西工学院生物与化学工程系,柳州545006 [2]广西大学化学与化学工程学院,南宁530004

出　　处：《分析化学》2007年第7期933-937,共5页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(No20665001);广西科学基金(No0640029);广西区研究生教育创新计划(No2006105930502m33)资助

摘　　要：在裸金电极上制备了L-半胱氨酸自组装膜金修饰电极（L-Cys／SAM—Au／CME），将自组装膜修饰电极用于不可逆双安培体系，利用阿魏酸在L—Cys／SAM—Au／CME上的氧化和KMnO4在裸金电极上的还原，构建双安培检测新体系，建立了在外加电压为0V条件下，流动注射双安培法直接测定阿魏酸的新方法。在0．05mol／LH2SO4溶液中，该氧化峰峰电流与阿魏酸浓度在5．0×10^-7-8．0×10^-5mol／L范围内呈线性关系（r=0．9961，n=10），其线性回归方程为i（nA）=4．16×10^7C＋50，在1．0×10^-4 -1．0×10^-3mol／L范围内呈线性关系（r=0．9955，n=5），其线性回归方程为i（nA）=5．6×10^6C＋300，检出限为1．2×10^-7mol／L。连续测定2．0×10^-5mol／L阿魏酸溶液25次，电流值RSD为1．20％，进样频率为80样／h。该方法具有较宽的线性范围、较高的选择性和灵敏度，样品处理方法简单快速，适于在线分析。对阿魏酸钠盐注射液中阿魏酸的测定结果满意。L-cysteine self-assembled monolayer modified electrode （L-Cys/SAM-Au/CME） has been fabricated on the surface of bare gold wire. The electrochemical behaviors of ferulic acid on the modified electrode were studied. The method of self-assembled monolayer modified electrode was applied to establish the flow-injection irreversible biamperometric analysis. Namely, the irreversible system is composed of electrocatalytic oxidation of ferulic acid at one L-cysteine gold modified electrode and reduction of permanganate at another bare gold electrode. This novel flow-injection irreversible biamperometric method of determination ferulic acid can run without the application of an external potential. In the 0.05 mol/L sulfuric acid, the oxidative peak current increases linearly with the concentration of ferulic acid in the range of 5 × 10^-7 - 8 × 10^-5mol/L, linear regression equation： i（nA） = 4.16 × 10^7C ＋ 50, and in the range of 1 ×10^-4 - 1 × 10^-3 mol/L, linear regression equation： i（nA） = 5.6 × 10^6C ＋ 300 with a sampling frequency of 80 samples per hour. The detection limit for ferulic acid is 1.2 × 10^ -7 mol/L and the RSD for 25 replicate determination of 2.00 × 10^-5 mol/L ferulic acid is 1. 2%. This proposed method has the advantage of wide linear range, high selectivity and sensitivity. The pertreatment procedure of the sample is simple, and it is suitable to online analysis. The method was applied to the analysis of sodium ferulate injection with satisfactory results.

关 键 词：L-半胱氨酸自组装膜 修饰电极 不可逆双安培法 金电极 阿魏酸 

分 类 号：O657.1[理学—分析化学]